Search Results

Search found 17884 results on 716 pages for 'column types'.

Page 549/716 | < Previous Page | 545 546 547 548 549 550 551 552 553 554 555 556  | Next Page >

• SQL Community – stronger than ever

  - by Rob Farley

  I posted a few hours ago about a reflection of the Summit, but I wanted to write another one for this month’s T-SQL Tuesday, hosted by Chris Yates. In January of this year, Adam Jorgensen and I joked around in a video that was used for the SQL Server 2012 launch. We were asked about SQLFamily, and we said how we were like brothers – how we could drive each other crazy (the look he gave me as I patted his stomach was priceless), but that we’d still look out for each other, just like in a real family. And this is really true. Last week at the PASS Summit, there was a lot going on. I was busy as always, as were many others. People told me their good news, their awful news, and some whinged to me about other people who were driving them crazy. But throughout this, people in the SQL Server community genuinely want the best for each other. I’m sure there are exceptions, but I don’t see much of this. Australians aren’t big on cheering for each other. Neither are the English. I think we see it as an American thing. It could be easy for me to consider that the SQL Community that I see at the PASS Summit is mainly there because it’s a primarily American organisation. But when you speak to people like sponsors, or people involved in several types of communities, you quickly hear that it’s not just about that – that PASS has something special. It goes beyond cheering, it’s a strong desire to see each other succeed. I see MVPs feel disappointed for those people who don’t get awarded. I see Summit speakers concerned for those who missed out on the chance to speak. I see chapter leaders excited about the opportunity to help other chapters. And throughout, I see a gentleness and love for people that you rarely see outside the church (and sadly, many churches don’t have it either). Chris points out that the M-W dictionary defined community as “a unified body of individuals”, and I feel like this is true of the SQL Server community. It goes deeper though. It’s not just unity – and we’re most definitely different to each other – it’s more than that. We all want to see each other grow. We all want to pull ourselves up, to serve each other, and to grow PASS into something more than it is today. In that other post of mine I wrote a bit about Paul White’s experience at his first Summit. His missus wrote to me on Facebook saying that she welled up over it. But that emotion was nothing about what I wrote – it was about the reaction that the SQL Community had had to Paul. Be proud of it, my SQL brothers and sisters, and never lose it.

  Read the article

• Solution for developers wanting to run a standalone WLS 10.3.6 server against JDev 11.1.1.6.0

  - by Chris Muir

  In my previous post I discussed how to install the 11.1.1.6.0 ADF Runtimes into a standalone WLS 10.3.6 server by using the ADF Runtime installer, not the JDeveloper installer.  Yet there's still a problem for developers here because JDeveloper 11.1.1.6.0 comes coupled with a WLS 10.3.5 server.  What if you want to develop, deploy and test with a 10.3.6 server?  Have we lost the ability to integrate the IDE and the WLS server where we can run and stop the server, deploy our apps automatically the server and more? JDeveloper actually solved this issue sometime back but not many people will have recognized the feature for what it does as it wasn't needed until now. Via the Application Server Navigator you can create 2 types of connections, one to a remote "standalone WLS" and another to an "integrated WLS".  It's this second option that is useful because what we can do is install a local standalone WLS 10.3.6 server on our developer PC, then create a separate "integrated WLS" connection to the standalone server.  Then by accessing your Application's properties through the Application menu -> Application Properties -> Run -> Bind to Integration Application Server option we can choose the newly created WLS server connection to work with our application. In this way JDeveloper will now treat the new server as if it was the integrated WLS.  It will start when we run and deploy our applications, terminate it at request and so on.  Of course don't forget you still need to install the ADF Runtimes for the server to be able to work with ADF applications. Note there is bug 13917844 lurking in the Application Server Navigator for at least JDev 11.1.1.6.0 and earlier.  If you right click the new connection and select "Start Server Instance" it will often start one of the other existing connections instead (typically the original IntegratedWebLogicServer connection).  If you want to manually start the server you can bypass this by using the Run menu -> Start Server Instance option which works correctly.

  Read the article

• SQL Community – stronger than ever

  - by Rob Farley

  I posted a few hours ago about a reflection of the Summit, but I wanted to write another one for this month’s T-SQL Tuesday, hosted by Chris Yates. In January of this year, Adam Jorgensen and I joked around in a video that was used for the SQL Server 2012 launch. We were asked about SQLFamily, and we said how we were like brothers – how we could drive each other crazy (the look he gave me as I patted his stomach was priceless), but that we’d still look out for each other, just like in a real family. And this is really true. Last week at the PASS Summit, there was a lot going on. I was busy as always, as were many others. People told me their good news, their awful news, and some whinged to me about other people who were driving them crazy. But throughout this, people in the SQL Server community genuinely want the best for each other. I’m sure there are exceptions, but I don’t see much of this. Australians aren’t big on cheering for each other. Neither are the English. I think we see it as an American thing. It could be easy for me to consider that the SQL Community that I see at the PASS Summit is mainly there because it’s a primarily American organisation. But when you speak to people like sponsors, or people involved in several types of communities, you quickly hear that it’s not just about that – that PASS has something special. It goes beyond cheering, it’s a strong desire to see each other succeed. I see MVPs feel disappointed for those people who don’t get awarded. I see Summit speakers concerned for those who missed out on the chance to speak. I see chapter leaders excited about the opportunity to help other chapters. And throughout, I see a gentleness and love for people that you rarely see outside the church (and sadly, many churches don’t have it either). Chris points out that the M-W dictionary defined community as “a unified body of individuals”, and I feel like this is true of the SQL Server community. It goes deeper though. It’s not just unity – and we’re most definitely different to each other – it’s more than that. We all want to see each other grow. We all want to pull ourselves up, to serve each other, and to grow PASS into something more than it is today. In that other post of mine I wrote a bit about Paul White’s experience at his first Summit. His missus wrote to me on Facebook saying that she welled up over it. But that emotion was nothing about what I wrote – it was about the reaction that the SQL Community had had to Paul. Be proud of it, my SQL brothers and sisters, and never lose it.

  Read the article

• WPF Control Toolkits Comparison for LOB Apps

  In preparation for a new WPF project Ive been researching options for WPF Control toolkits.  While we want a lot of the benefits of WPF, the application is a fairly typical line of business application (LOB).  So were not focused on things like media and animations, but instead a simple, solid, intuitive, and modern user interface that allows for well architected separation of business logic and presentation layers. While WPF is mature, it hasnt lived the long life that Winforms has yet, so there is still a lot of room for third party and community control toolkits to fill the gaps between the controls that ship with the Framework.  There are two such gaps I was concerned about.  As this is an LOB app, we have needs for presenting lots of data and not surprisingly much of it is in grid format with the need for high performance, grouping, inline editing, aggregation, printing and exporting and things that weve been doing with LOB apps for a long time.  In addition we want a dashboard style for the UI in which the user can rearrange and shrink and grow tiles that house the content and functionality.  From a cost perspective, building these types of well performing controls from scratch doesnt make sense.  So I evaluated what you get from the .NET Framework along with a few different options for control toolkits.  I tried to be fairly thorough, but know that this isnt a detailed benchmarking comparison or intense evaluation.  Its just meant to be a feature set comparison to be used when thinking about building an LOB app in WPF.  I tried to list important feature differences and notes based on my experience with the trial versions and what I found in documentation and reference materials and samples.  Ive also listed the importance of the controls based on how I think they are needed in LOB apps.  There are several toolkits available, but given I dont have unlimited time, I picked just a few.  Maybe Ill add on more later.  The toolkits I compared are: Teleriks RadControls for WPF since I had heard some good things about Telerik Infragistics NetAdvantage WPF since both I and the customer have some experience with the vendors tools WPF Toolkit on codeplex since many of my colleagues have used it Blacklight codeplex project which had WPF support for the Tile View control  (with Release 4.3 WPF is not going to be supported in favor of focusing only on SilverLight controls, so I dropped that from the comparison) Click Here to Download the WPF Control Toolkits Comparison Hopefully this helps someone out there.  Feel free to post a comment on your experiences or if you think something I listed is incorrect or missing.  Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

  Read the article

• GWT: Generate more complete crawl error report

  - by Mike

  I'm a developer in charge of managing Webmasters and related issues (including correcting crawl errors) for dozens (hundreds, maybe?) of active sites and as part of my duties I create a report of every discrepancy, including all pages generating a 404 and all pages that link to those pages. Currently within Webmaster Tools I'm able to download a csv file of all pages with a 404 response, but I'm then having to manually click on every single one of those links and copy the "linked from" field to paste into my spreadsheet. This is extremely tedious and seems unnecessary; I would expect the ability to download all that data at once. I'm ultimately looking for the end result of one csv file that has every url with a 404, but also has every url that links to each one of them. Am I overlooking this functionality somewhere or does anyone have a good solution? Edit 1 (2/11/2013): Example of what the csv output looks like now: URL,Response Code,News Error,Detected,Category http://www.abcdef.com/123.php,404,,11/12/13,Not found http://www.abcdef.com/456.php,404,,11/12/13,Not found Which is great, but let's say 123.php has 5 pages that link to it. Now I have to duplicate that row in my spreadsheet 4 more times, then go into Webmasters, get all the url's that link to the page, and add that data to my spreadsheet. The output I would prefer: URL,Response Code,Linked From,News Error,Detected,Category http://www.abcdef.com/123.php,404,http://www.ghijkl.com/naughtypage1.php,,11/12/13,Not found http://www.abcdef.com/123.php,404,http://www.ghijkl.com/naughtypage2.php,,11/12/13,Not found http://www.abcdef.com/123.php,404,http://www.ghijkl.com/naughtypage3.php,,11/12/13,Not found http://www.abcdef.com/456.php,404,http://www.ghijkl.com/naughtypage1.php,,11/12/13,Not found http://www.abcdef.com/456.php,404,http://www.ghijkl.com/naughtypage2.php,,11/12/13,Not found http://www.abcdef.com/456.php,404,http://www.ghijkl.com/naughtypage3.php,,11/12/13,Not found Note the (hypothetical) addition of a "Linked From" column, as well as the fact there are only 2 unique URL's now (like before) but all of the "Linked To" pages are shown in one report. Edit 2 (2/12/2013): To clarify, my question is less about detecting and correcting 404's, but more about generating a report of what Google has listed as errors. Oftentimes, these errors aren't even valid anymore but I still need documentation to show that Google detected a problem and that problem is now fixed. Many of the "linked from" url's I find are actually outdated, cached resources. For example, I'll frequently see that the linked-from url is the sitemap, which is actually an old sitemap cached by Google that points to an old page. Neither the sitemap or old page exist, but they still appear in my crawl error reports because they are cached resources.

  Read the article

• Need suggestion for Mutiple Windows application design

  - by King Chan

  This was previously posted in StackOverflow, I just moved to here... I am using VS2008, MVVM, WPF, Prism to make a mutiple window CRM Application. I am using MidWinow in my MainWindow, I want Any ViewModel would able to make request to MainWindow to create/add/close MidChildWindow, ChildWindow(from WPF Toolkit), Window (the Window type). ViewModel can get the DialogResult from the ChildWindow its excutes. MainWindow have control on all opened window types. Here is my current approach: I made Dictionary of each of the windows type and stores them into MainWindow class. For 1, i.e in a CustomerInformationView, its CustomerInformationViewModel can execute EditCommand and use EventAggregator to tell MainWindow to open a new ChildWindow. CustomerInformationViewModel: CustomerEditView ceView = new CustomerEditView (); CustomerEditViewModel ceViewModel = CustomerEditViewModel (); ceView.DataContext = ceViewModel; ChildWindow cWindow = new ChildWindow(); cWindow.Content = ceView; MainWindow.EvntAggregator.GetEvent<NewWindowEvent>().Publish(new WindowEventArgs(ceViewModel.ViewModeGUID, cWindow )); cWindow.Show(); Notice that all my ViewModel will generates a Guid for help identifies the ChildWindow from MainWindow's dictionary. Since I will only be using 1 View 1 ViewModel for every Window. For 2. In CustomerInformationViewModel I can get DialogResult by OnClosing event from ChildWindow, in CustomerEditViewModel can use Guid to tell MainWindow to close the ChildWindow. Here is little question and problems: Is it good idea to use Guid here? Or should I use HashKey from ChildWindow? My MainWindows contains windows reference collections. So whenever window close, it will get notifies to remove from the collection by OnClosing event. But all the Windows itself doesn't know about its associated Guid, so when I remove it, I have to search for every KeyValuePair to compares... I still kind of feel wrong associate ViewModel's Guid for ChildWindow, it would make more sense if ChildWindow has it own ID then ViewModel associate with it... But most important, is there any better approach on this design? How can I improve this better?

  Read the article

• Am I deluding myself? Business analyst transition to programmer

  - by Ryan

  Current job: Working as the lead business analyst for a Big 4 firm, leading a team of developers and testers working on a large scale re-platforming project (4 onshore dev, 4 offshore devs, several onshore/offshore testers). Also work in a similar capacity on other smaller scale projects. Extent of my role: Gathering/writing out requirements, creating functional specifications, designing the UI (basically mapping out all front-end aspects of the system), working closely with devs to communicate/clarify requirements and come up with solutions when we hit roadblocks, writing test cases (and doing much of the testing), working with senior management and key stakeholders, managing beta testers, creating user guides and leading training sessions, providing key technical support. I also write quite a few macros in Excel using VBA (several of my macros are now used across the entire firm, so there are maybe around 1000 people using them) and use SQL on a daily basis, both on the SQL compact files the program relies on, our SQL Server data and any Access databases I create. The developers feel that I am quite good in this role because I understand a lot about programming, inherent system limitations, structure of the databases, etc so it's easier for me to communicate ideas and come up with suggestions when we face problems. What really interests me is developing software. I do a fair amount of programming in VBA and have been wanting to learn C# for awhile (the dev team uses C# - I review code occasionally for my own sake but have not had any practical experience using it). I'm interested in not just the business process but also the technical side of things, so the traditional BA role doesn't really whet my appetite for the kind of stuff I want to do. Right now I have a few small projects that managers have given me and I'm finding new ways to do them (like building custom Access applications), so there's a bit here and there to keep me interested. My question is this: what I would like to do is create custom Excel or Access applications for small businesses as a freelance business (working as a one-man shop; maybe having an occasional contractor depending on a project's complexity). This would obviously start out as a part-time venture while I have a day job, but eventually become a full-time job. Am I deluding myself to thinking I can go from BA/part-time VBA programmer to making a full-time go of a freelance business (where I would be starting out just writing custom Excel/Access apps in VBA)? Or is this type of thing not usually attempted until someone gains years of full-time programming experience? And is there even a market for these types of applications amongst small businesses (and maybe medium-sized) businesses?

  Read the article

• Telesharp – An Application Repository for .NET applications

  - by cibrax

  A year ago, we released SO-Aware as our first product in Tellago Studios. SO-Aware represented a new way to manage web services and all the related artifacts like configuration, tests or monitoring data in the Microsoft stack. It was based on the idea of using a lightweight SOA governance approach with a central repository exposed through RESTful services. At that point, we thought the same idea could be extended to enterprise applications in general by providing a generic repository for many of the runtime or design time artifacts generated during the development like configuration, application description or topology (a high level view of the components that made up a system), logging information or binaries. It took us several months to give a form to that idea and implement it as a product, but it is finally here and I am very proud to announce the release today under the name of “TeleSharp”. Telesharp provides in a nutshell the following features, 1. Configure your application topology in a central repository. Application topology in this context means that you can decompose your application and describe it in terms of components and how they interact each other. For example, you can tell that the CRM system is made up of a couple of WCF services and a ASP.NET MVC front end. 2. Centralize configuration for your applications and components.  You can import existing .NET configuration sections into the repository and associate them to the different components. In addition, environment overrides are supported for the configuration sections. We provide tooling and extensions in Visual Studio for managing all the configuration, and a set of powershell commands for automating the configuration deployment. 3. Browse all the assemblies and types remotely in your application servers in a web browser using an interface similar to any of the existing .NET reflection tools. You can easily determine this way whether the server is running the correct version of your applications. 4. Centralize logging and exception management into the repository. You get different reports and a pivot viewer experience for browsing all the different logging information generated by your applications. In addition, TeleSharp provides different providers for pushing the logging information to the central repository using well-known frameworks like ELMAH, Log4Net, EntLib or even Windows ETW.  The central repository itself is implemented as a set of OData services that any application can easily consume using regular Http. You can read more details in this introductory post If you think this product can be a good fit in your organization, you can request a trial version in our Tellago Studios website.

  Read the article

• How do I get long command lines to wrap to the next line?

  - by BrianH

  Edit It was my .bashrc file. I've copied the same profile from machine to machine, and I used special characters in my $PS1 that are somehow throwing it off. I'm now sticking with the standard bash variables for my $PS1. Thanks to @ændrük for the tip on the .bashrc! ...End Edit... Something I have noticed in Ubuntu for a long time that has been frustrating to me is when I am typing a command at the command line that gets longer (wider) than the terminal width, instead of wrapping to a new line, it goes back to column 1 on the same line and starts over-writing the beginning of my command line. (It doesn't actually overwrite the actual command, but visually, it is overwriting the text that was displayed). It's hard to explain without seeing it, but let's say my terminal was 20 characters wide (Mine is more like 120 characters - but for the sake of an example), and I want to echo the English alphabet. What I type is this: echo abcdefghijklmnopqrstuvwxyz But what my terminal looks like before I hit the key is: pqrstuvwxyzghijklmno When I hit enter, it echos abcdefghijklmnopqrstuvwxyz so I know the command was received properly. It just wrapped my typing after the "o" and started over on the same line. What I would expect to happen, if I typed this command in on a terminal that was only 20 characters wide would be this: echo abcdefghijklmno pqrstuvwxyz Background: I am using bash as my shell, and I have this line in my ~/.bashrc: set -o vi to be able to navigate the command line with VI commands. I am currently using Ubuntu 10.10 server, and connecting to the server with Putty. In any other environment I have worked in, if I type a long command line, it will add a new line underneath the line I am working on when my command gets longer than the terminal width and when I keep typing I can see my command on 2 different lines. But for as long as I can remember using Ubuntu, my long commands only occupy 1 line. This also happens when I am going back to previous commands in the history (I hit Esc, then 'K' to go back to previous commands) - when I get to a previous command that was longer than the terminal width, the command line gets mangled and I cannot tell where I am at in the command. The only work-around I have found to see the entire long command is to hit "Esc-V", which opens up the current command in a VI editor. I don't think I have anything odd in my .bashrc file. I commented out the "set -o vi" line, and I still had the problem. I downloaded a fresh copy of Putty and didn't make any changes to the configuration - I just typed in my host name to connect, and I still have the problem, so I don't think it's anything with Putty (unless I need to make some config changes) Has anyone else had this problem, and can anyone think of how to fix it? Thanks in advance! Brian

  Read the article

• Is There a Real Advantage to Generic Repository?

  - by Sam

  Was reading through some articles on the advantages of creating Generic Repositories for a new app (example). The idea seems nice because it lets me use the same repository to do several things for several different entity types at once: IRepository repo = new EfRepository(); // Would normally pass through IOC into constructor var c1 = new Country() { Name = "United States", CountryCode = "US" }; var c2 = new Country() { Name = "Canada", CountryCode = "CA" }; var c3 = new Country() { Name = "Mexico", CountryCode = "MX" }; var p1 = new Province() { Country = c1, Name = "Alabama", Abbreviation = "AL" }; var p2 = new Province() { Country = c1, Name = "Alaska", Abbreviation = "AK" }; var p3 = new Province() { Country = c2, Name = "Alberta", Abbreviation = "AB" }; repo.Add<Country>(c1); repo.Add<Country>(c2); repo.Add<Country>(c3); repo.Add<Province>(p1); repo.Add<Province>(p2); repo.Add<Province>(p3); repo.Save(); However, the rest of the implementation of the Repository has a heavy reliance on Linq: IQueryable<T> Query(); IList<T> Find(Expression<Func<T,bool>> predicate); T Get(Expression<Func<T,bool>> predicate); T First(Expression<Func<T,bool>> predicate); //... and so on This repository pattern worked fantastic for Entity Framework, and pretty much offered a 1 to 1 mapping of the methods available on DbContext/DbSet. But given the slow uptake of Linq on other data access technologies outside of Entity Framework, what advantage does this provide over working directly with the DbContext? I attempted to write a PetaPoco version of the Repository, but PetaPoco doesn't support Linq Expressions, which makes creating a generic IRepository interface pretty much useless unless you only use it for the basic GetAll, GetById, Add, Update, Delete, and Save methods and utilize it as a base class. Then you have to create specific repositories with specialized methods to handle all the "where" clauses that I could previously pass in as a predicate. Is the Generic Repository pattern useful for anything outside of Entity Framework? If not, why would someone use it at all instead of working directly with Entity Framework? Edit: Original link doesn't reflect the pattern I was using in my sample code. Here is an (updated link).

  Read the article

• Question about BoundingSpheres and Ray intersections

  - by NDraskovic

  I'm working on a XNA project (not really a game) and I'm having some trouble with picking algorithm. I have a few types of 3D models that I draw to the screen, and one of them is a switch. So I'm trying to make a picking algorithm that would enable the user to click on the switch and that would trigger some other function. The problem is that the BoundingSphere.Intersect() method always returns null as result. This is the code I'm using: In the declaration section: ` //Basic matrices private Matrix world = Matrix.CreateTranslation(new Vector3(0, 0, 0)); private Matrix view = Matrix.CreateLookAt(new Vector3(10, 10, 10), new Vector3(0, 0, 0), Vector3.UnitY); private Matrix projection = Matrix.CreatePerspectiveFieldOfView(MathHelper.ToRadians(45), 800f / 600f, 0.01f, 100f); //Collision detection variables Viewport mainViewport; List<BoundingSphere> spheres = new List<BoundingSphere>(); Ray ControlRay; Vector3 nearPoint, farPoint, nearPlane, farPlane, direction; ` And then in the Update method: ` nearPlane = new Vector3((float)Mouse.GetState().X, (float)Mouse.GetState().Y, 0.0f); farPlane = new Vector3((float)Mouse.GetState().X, (float)Mouse.GetState().Y, 10.0f); nearPoint = GraphicsDevice.Viewport.Unproject(nearPlane, projection, view, world); farPoint = GraphicsDevice.Viewport.Unproject(farPlane, projection, view, world); direction = farPoint - nearPoint; direction.Normalize(); ControlRay = new Ray(nearPoint, direction); if (spheres.Count != 0) { for (int i = 0; i < spheres.Count; i++) { if (spheres[i].Intersects(ControlRay) != null) { Window.Title = spheres[i].Center.ToString(); } else { Window.Title = "Empty"; } } ` The "spheres" list gets filled when the 3D object data gets loaded (I read it from a .txt file). For every object marked as switch (I use simple numbers to determine which object is to be drawn), a BoundingSphere is created (center is on the coordinates of the 3D object, and the diameter is always the same), and added to the list. The objects are drawn normally (and spheres.Count is not 0), I can see them on the screen, but the Window title always says "Empty" (of course this is just for testing purposes, I will add the real function when I get positive results) meaning that there is no intersection between the ControlRay and any of the bounding spheres. I think that my basic matrices (world, view and projection) are making some problems, but I cant figure out what. Please help.

  Read the article

• Subterranean IL: Exception handling 1

  - by Simon Cooper

  Today, I'll be starting a look at the Structured Exception Handling mechanism within the CLR. Exception handling is quite a complicated business, and, as a result, the rules governing exception handling clauses in IL are quite strict; you need to be careful when writing exception clauses in IL. Exception handlers Exception handlers are specified using a .try clause within a method definition. .try <TryStartLabel> to <TryEndLabel> <HandlerType> handler <HandlerStartLabel> to <HandlerEndLabel> As an example, a basic try/catch block would be specified like so: TryBlockStart: // ... leave.s CatchBlockEndTryBlockEnd:CatchBlockStart: // at the start of a catch block, the exception thrown is on the stack callvirt instance string [mscorlib]System.Object::ToString() call void [mscorlib]System.Console::WriteLine(string) leave.s CatchBlockEnd CatchBlockEnd: // method code continues... .try TryBlockStart to TryBlockEnd catch [mscorlib]System.Exception handler CatchBlockStart to CatchBlockEnd There are four different types of handler that can be specified: catch <TypeToken> This is the standard exception catch clause; you specify the object type that you want to catch (for example, [mscorlib]System.ArgumentException). Any object can be thrown as an exception, although Microsoft recommend that only classes derived from System.Exception are thrown as exceptions. filter <FilterLabel> A filter block allows you to provide custom logic to determine if a handler block should be run. This functionality is exposed in VB, but not in C#. finally A finally block executes when the try block exits, regardless of whether an exception was thrown or not. fault This is similar to a finally block, but a fault block executes only if an exception was thrown. This is not exposed in VB or C#. You can specify multiple catch or filter handling blocks in each .try, but fault and finally handlers must have their own .try clause. We'll look into why this is in later posts. Scoped exception handlers The .try syntax is quite tricky to use; it requires multiple labels, and you've got to be careful to keep separate the different exception handling sections. However, starting from .NET 2, IL allows you to use scope blocks to specify exception handlers instead. Using this syntax, the example above can be written like so: .try { // ... leave.s EndSEH}catch [mscorlib]System.Exception { callvirt instance string [mscorlib]System.Object::ToString() call void [mscorlib]System.Console::WriteLine(string) leave.s EndSEH}EndSEH:// method code continues... As you can see, this is much easier to write (and read!) than a stand-alone .try clause. Next time, I'll be looking at some of the restrictions imposed by SEH on control flow, and how the C# compiler generated exception handling clauses.

  Read the article

• How can I solve the same problems a CB-architecture is trying to solve without using hacks? [on hold]

  - by Jefffrey

  A component based system's goal is to solve the problems that derives from inheritance: for example the fact that some parts of the code (that are called components) are reused by very different classes that, hypothetically, would lie in a very different branch of the inheritance tree. That's a very nice concept, but I've found out that CBS is often hard to accomplish without using ugly hacks. Implementations of this system are often far from clean. But I don't want to discuss this any further. My question is: how can I solve the same problems a CBS try to solve with a very clean interface? (possibly with examples, there are a lot of abstract talks about the "perfect" design already). Here's an example I was going for before realizing I was just reinventing inheritance again: class Human { public: Position position; Movement movement; Sprite sprite; // other human specific components }; class Zombie { Position position; Movement movement; Sprite sprite; // other zombie specific components }; After writing that I realized I needed an interface, otherwise I would have needed N containers for N different types of objects (or to use boost::variant to gather them all together). So I've thought of polymorphism (move what systems do in a CBS design into class specific functions): class Entity { public: virtual void on_event(Event) {} // not pure virtual on purpose virtual void on_update(World) {} virtual void on_draw(Window) {} }; class Human { private: Position position; Movement movement; Sprite sprite; public: virtual void on_event(Event) { ... } virtual void on_update(World) { ... } virtual void on_draw(Window) { ... } }; class Zombie { private: Position position; Movement movement; Sprite sprite; public: virtual void on_event(Event) { ... } virtual void on_update(World) { ... } virtual void on_draw(Window) { ... } }; Which was nice, except for the fact that now the outside world would not even be able to know where a Human is positioned (it does not have access to its position member). That would be useful to track the player position for collision detection or if on_update the Zombie would want to track down its nearest human to move towards him. So I added const Position& get_position() const; to both the Zombie and Human classes. And then I realized that both functionality were shared, so it should have gone to the common base class: Entity. Do you notice anything? Yes, with that methodology I would have a god Entity class full of common functionality (which is the thing I was trying to avoid in the first place).

  Read the article

• Stop trying to be perfect

  - by Kyle Burns

  Yes, Bob is my uncle too.  I also think the points in the Manifesto for Software Craftsmanship (manifesto.softwarecraftsmanship.org) are all great.  What amazes me is that tend to confuse the term “well crafted” with “perfect”.  I'm about to say something that will make Quality Assurance managers and many development types as well until you think about it as a craftsman – “Stop trying to be perfect”. Now let me explain what I mean.  Building software, as with building almost anything, often involves a series of trade-offs where either one undesired characteristic is accepted as necessary to achieve another desired one (or maybe stave off one that is even less desirable) or a desirable characteristic is sacrificed for the same reasons.  This implies that perfection itself is unattainable.  What is attainable is “sufficient” and I think that this really goes to the heart both of what people are trying to do with Agile and with the craftsmanship movement.  Simply put, sufficient software drives the greatest business value.   I've been in many meetings where “how can we keep anything from ever going wrong” has become the thing that holds us in analysis paralysis.  I've also been the guy trying way too hard to perfect some function to make sure that every edge case is accounted for.  Somewhere in there, something a drill instructor said while I was in boot camp occurred to me.  In response to being asked a question by another recruit having to do with some edge case (I can barely remember the context), he said “What if grasshoppers had machine guns?  Would the birds still **** with them?”  It sounds funny, but there's a lot of wisdom in those words.   “Sufficient” is different for every situation and it’s important to understand what sufficient means in the context of the work you’re doing.  If I’m writing a timesheet application (and please shoot me if I am), I’m going to have a much higher tolerance for imperfection than if you’re writing software to control life support systems on spacecraft.  I’m also likely to have less need for high volume performance than if you’re writing software to control stock trading transactions.   I’d encourage anyone who has read this far to instead of trying to be perfect, try to create software that is sufficient in every way.  If you’re working to make a component that is sufficient “better”, ask yourself if there is any component left that is not yet sufficient.  If the answer is “yes” you’re working on the wrong thing and need to adjust.  If the answer is “no”, why aren’t you shipping and delivering business value?

  Read the article

• Turn Chrome’s New Tab Page into an Ubuntu Forums Powerhouse

  - by Asian Angel

  There’s a lot of start page plug-ins for Google Chrome, but if you’re an Ubuntu Forums enthusiast, you might be interested in the powerful UbuntuForums.org Start Page extension. Using the Ubuntu Forums Chrome Start Page Once you’ve installed the extension and opened a new tab, you’ll notice quite a difference from the boring default “New Tab Page”. While you may look at this and wonder if what you see is all that there is to it, there’s actually a lot of hidden customization and functionality. The upper left corner is where you will control the content displayed in the “Ubuntu New Tab Page”. The “Buttons Toolbar” that you see at the top lets you shift between the types of content viewed, from RSS feeds to bookmarks and more. This entire set of links provides direct links to the appropriate section in the Ubuntu Forums. As with the set of links pictured above each of these will open in a new tab when clicked on. There’s even a feature to browse wallpapers from DesktopNexus with categories on the left and pictures to the right. If you want to return to the regular layout you should use the “Start Page Link” highlighted here. Options The options will allow you to customize the colors shown in the “Ubuntu New Tab Page” to create a very nice match to your current browser and/or system theme if desired. You can also do some customization to the fonts, “Bookmark Shortcuts”, and populate the “Custom Links Section” in the main page. Conclusion If you are an Ubuntu enthusiast then this will be a very useful extension to add to your browser. The wealth of direct links and built-in functionality make this extension worth trying. Links Download the Ubuntuforums.org Start Page extension (Google Chrome Extensions) Similar Articles Productive Geek Tips Turn Off Auto-Play of Audio and Video CDs and DVDs in UbuntuScroll Backwards From the Ubuntu Server Command LineAnnouncing the How-To Geek ForumsDisable the System Beep on Ubuntu EdgyEnable Smooth fonts on Ubuntu Linux TouchFreeze Alternative in AutoHotkey The Icy Undertow Desktop Windows Home Server – Backup to LAN The Clear & Clean Desktop Use This Bookmarklet to Easily Get Albums Use AutoHotkey to Assign a Hotkey to a Specific Window Latest Software Reviews Tinyhacker Random Tips DVDFab 6 Revo Uninstaller Pro Registry Mechanic 9 for Windows PC Tools Internet Security Suite 2010 Gadfly is a cool Twitter/Silverlight app Enable DreamScene in Windows 7 Microsoft’s “How Do I ?” Videos Home Networks – How do they look like & the problems they cause Check Your IMAP Mail Offline In Thunderbird Follow Finder Finds You Twitter Users To Follow

  Read the article

• The Solution

  - by Patrick Liekhus

  So I recently attended a class about time management as well as read the book “The Seven Habits of Highly Effective People” by Stephen Covey.  Both have been instrumental in helping me get my priorities aligned as well as keep me focused. The reason I bring this up is that it gave me a great idea for a small application with which to create a great technical stack solution that would be easy to demo and explain.  Therefore, the project from this point forward with be the Liekhus.TimeTracker application which will bring some the time management skills that I have acquired into a technical implementation.  The idea is rather simple, but leverages some of the basic principles of Covey along with some of the worksheets that I garnered from class.  The basics are as such: 1) a plan is a must have and 2) write it down!  A plan not written down is just an idea.  How many times have you had an idea that didn’t materialize?  Exactly.  Hence why I am writing it all down now! The worksheet consists of a few simple columns that I will outline below as well as some modifications that I made according to the Covey habits.  The worksheet looks like the following: Status Issue Area CQ Notes P  F  L     1234   P  F  L     1234   P  F  L     1234   P  F  L     1234   P  F  L     1234   P  F  L     1234   P  F  L     1234   P  F  L     1234   P  F  L     1234   The idea is really simple and straightforward; you write down all your tasks and keep track of them along the way.  The status stands for (P)ending, (F)inished or (L)ater.  You write a quick title for the issue and select the CQ (Covey Quadrant) with which the issue occurs.  The notes section is for things that happen while you are working through the issue.  And last, but not least, is the Area column that I added as a way to identify the Role or Area of your life that this task falls within based upon Covey’s teachings. The second part of this application is a simple phone log that allows you to track your phone conversations throughout the day.  All of this is currently done on a sheet of paper, but being involved in technology, I want it to have bells and whistles.  Therefore, this is my simple idea for a project that will allow me to test my theories about coding and implementations.  Stay tuned as the next session will be flushing out the concept and coming up with user stories to begin the SCRUM process. Thanks

  Read the article

• Data Transformation Pipeline

  - by davenewza

  I have create some kind of data pipeline to transform coordinate data into more useful information. Here is the shell of pipeline: public class PositionPipeline { protected List<IPipelineComponent> components; public PositionPipeline() { components = new List<IPipelineComponent>(); } public PositionPipelineEntity Process(Position position) { foreach (var component in components) { position = component.Execute(position); } return position; } public PositionPipeline RegisterComponent(IPipelineComponent component) { components.Add(component); return this; } } Every IPipelineComponent accepts and returns the same type - a PositionPipelineEntity. Code: public interface IPipelineComponent { PositionPipelineEntity Execute(PositionPipelineEntity position); } The PositionPipelineEntity needs to have many properties, many which are unused in certain components and required in others. Some properties will also have become redundant at the end of the pipeline. For example, these components could be executed: TransformCoordinatesComponent: Parse the raw coordinate data into a Coordinate type. DetermineCountryComponent: Determine and stores country code. DetermineOnRoadComponent: Determine and store whether coordinate is on a road. Code: pipeline .RegisterComponent(new TransformCoordinatesComponent()) .RegisterComponent(new DetermineCountryComponent()) .RegisterComponent(new DetermineOnRoadComponent()); pipeline.Process(positionPipelineEntity); The PositionPipelineEntity type: public class PositionPipelineEntity { // Only relevant to the TransformCoordinatesComponent public decimal RawCoordinateLatitude { get; set; } // Only relevant to the TransformCoordinatesComponent public decimal RawCoordinateLongitude { get; set; } // Required by all components after TransformCoordinatesComponent public Coordinate CoordinateLatitude { get; set; } // Required by all components after TransformCoordinatesComponent public Coordinate CoordinateLongitude { get; set; } // Set in DetermineCountryComponent, not required anywhere. // Requires CoordinateLatitude and CoordinateLongitude (TransformCoordinatesComponent) public string CountryCode { get; set; } // Set in DetermineOnRoadComponent, not required anywhere. // Requires CoordinateLatitude and CoordinateLongitude (TransformCoordinatesComponent) public bool OnRoad { get; set; } } Problems: I'm very concerned about the dependency that a component has on properties. The way to solve this would be to create specific types for each component. The problem then is that I cannot chain them together like this. The other problem is the order of components in the pipeline matters. There is some dependency. The current structure does not provide any static or runtime checking for such a thing. Any feedback would be appreciated.

  Read the article

• Sync Google Calendar with SharePoint Calendar

  - by dataintegration

  The ADO.NET Providers for Google and SharePoint make it easy to retrieve and update data in both Google's web services and SharePoint. This article shows how the SQL interface to data makes it easy to build applications that need to move data from one source to another. The application described here is a demo Windows application that synchronizes calendar events between Google and SharePoint, but the RSSBus Providers can be used to achieve integrations on both the .NET and the Java platforms, including more sophisticated features like full automation. Getting the Events Step 1: Google accounts can have several calendars. Obtain a list of a user's Google Calendars by issuing a query to the Calendars table. For example: SELECT * FROM Calendars. Step 2: In order to get a list of the events from a given Google Calendar, issue a query to the CalendarEvents table while specifying the CalendarId from the Calendars table. The resulting events can be further filtered by using the StartDateTime or EndDateTime columns. For example: SELECT * FROM CalendarEvents WHERE (CalendarId = '[email protected]') AND (StartDateTime >= '1/1/2012') AND (StartDateTime <= '2/1/2012') Step 3: SharePoint stores data in Lists. There are various types of lists, e.g., document lists and calendar lists. A SharePoint account can have several lists of the same type. To find all the calendar lists in SharePoint, use the ListLists stored procedure and inspect the BaseTemplate column. Step 4: The SharePoint data provider models each SharPoint list as a table. Get the events in a particular calendar by querying the table with the same name as the list. The events may be filtered further by specifying the EventDate or EndDate columns. For example: SELECT * FROM Calendar WHERE (EventDate >= '1/1/2012') AND (EventDate <= '2/1/2012') Synchronizing the Events Synchronizing the events is a simple process. Once the events from Google and SharePoint are available they can be compared and synchronized based on user preference. The sample application does this based on user input, but it is easy to create one that does the synchronization automatically. The INSERT, UPDATE, and DELETE statements available in both data providers makes it easy to create, update, or delete events as needed. Pre-Built Demo Application The executable for the demo application can be downloaded here. Note that this demo is built using BETA builds of the ADO.NET Provider for Google V2 and ADO.NET Provider for SharePoint V2, and will expire in 2013. Source Code You can download the full source of the demo application here. You will need the Google ADO.NET Data Provider V2 and the SharePoint ADO.NET Data Provider V2, which can be obtained here.

  Read the article

• Questions about identifying the components in MVC

  - by luiscubal

  I'm currently developing an client-server application in node.js, Express, mustache and MySQL. However, I believe this question should be mostly language and framework agnostic. This is the first time I'm doing a real MVC application and I'm having trouble deciding exactly what means each component. (I've done web applications that could perhaps be called MVC before, but I wouldn't confidently refer to them as such) I have a server.js that ties the whole application together. It does initialization of all other components (including the database connection, and what I think are the "models" and the "views"), receiving HTTP requests and deciding which "views" to use. Does this mean that my server.js file is the controller? Or am I mixing code that doesn't belong there? What components should I break the server.js file into? Some examples of code that's in the server.js file: var connection = mysql.createConnection({ host : 'localhost', user : 'root', password : 'sqlrevenge', database : 'blog' }); //... app.get("/login", function (req, res) { //Function handles a GET request for login forms if (process.env.NODE_ENV == 'DEVELOPMENT') { mu.clearCache(); } session.session_from_request(connection, req, function (err, session) { if (err) { console.log('index.js session error', err); session = null; } login_view.html(res, user_model, post_model, session, mu); //I named my view functions "html" for the case I might want to add other output types (such as a JSON API), or should I opt for completely separate views then? }); }); I have another file that belongs named session.js. It receives a cookies object, reads the stored data to decide if it's a valid user session or not. It also includes a function named login that does change the value of cookies. First, I thought it would be part of the controller, since it kind of dealt with user input and supplied data to the models. Then, I thought that maybe it was a model since it dealt with the application data/database and the data it supplies is used by views. Now, I'm even wondering if it could be considered a View, since it outputs data (cookies are part of HTTP headers, which are output)

  Read the article

• How to make a queue switches from FIFO mode to priority mode?

  - by enzom83

  I would like to implement a queue capable of operating both in the FIFO mode and in the priority mode. This is a message queue, and the priority is first of all based on the message type: for example, if the messages of A type have higher priority than the messages of the B type, as a consequence all messages of A type are dequeued first, and finally the messages of B type are dequeued. Priority mode: my idea consists of using multiple queues, one for each type of message; in this way, I can manage a priority based on the message type: just take first the messages from the queue at a higher priority and progressively from lower priority queues. FIFO mode: how to handle FIFO mode using multiple queues? In other words, the user does not see multiple queues, but it uses the queue as if it were a single queue, so that the messages leave the queue in the order they arrive when the priority mode is disabled. In order to achieve this second goal I have thought to use a further queue to manage the order of arrival of the types of messages: let me explain better with the following code snippet. int NUMBER_OF_MESSAGE_TYPES = 4; int CAPACITY = 50; Queue[] internalQueues = new Queue[NUMBER_OF_MESSAGE_TYPES]; Queue<int> queueIndexes = new Queue<int>(CAPACITY); void Enqueue(object message) { int index = ... // the destination queue (ie its index) is chosen according to the type of message. internalQueues[index].Enqueue(message); queueIndexes.Enqueue(index); } object Dequeue() { if (fifo_mode_enabled) { // What is the next type that has been enqueued? int index = queueIndexes.Dequeue(); return internalQueues[index].Dequeue(); } if (priority_mode_enabled) { for(int i=0; i < NUMBER_OF_MESSAGE_TYPES; i++) { int currentQueueIndex = i; if (!internalQueues[currentQueueIndex].IsEmpty()) { object result = internalQueues[currentQueueIndex].Dequeue(); // The following statement is fundamental to a subsequent switching // from priority mode to FIFO mode: the messages that have not been // dequeued (since they had lower priority) remain in the order in // which they were queued. queueIndexes.RemoveFirstOccurrence(currentQueueIndex); return result; } } } } What do you think about this idea? Are there better or more simple implementations?

  Read the article

• SQL: empty string vs NULL value

  - by Jacek Prucia

  I know this subject is a bit controversial and there are a lot of various articles/opinions floating around the internet. Unfortunatelly, most of them assume the person doesn't know what the difference between NULL and empty string is. So they tell stories about surprising results with joins/aggregates and generally do a bit more advanced SQL lessons. By doing this, they absolutely miss the whole point and are therefore useless for me. So hopefully this question and all answers will move subject a bit forward. Let's suppose I have a table with personal information (name, birth, etc) where one of the columns is an email address with varchar type. We assume that for some reason some people might not want to provide an email address. When inserting such data (without email) into the table, there are two available choices: set cell to NULL or set it to empty string (''). Let's assume that I'm aware of all the technical implications of choosing one solution over another and I can create correct SQL queries for either scenario. The problem is even when both values differ on the technical level, they are exactly the same on logical level. After looking at NULL and '' I came to a single conclusion: I don't know email address of the guy. Also no matter how hard i tried, I was not able to sent an e-mail using either NULL or empty string, so apparently most SMTP servers out there agree with my logic. So i tend to use NULL where i don't know the value and consider empty string a bad thing. After some intense discussions with colleagues i came with two questions: am I right in assuming that using empty string for an unknown value is causing a database to "lie" about the facts? To be more precise: using SQL's idea of what is value and what is not, I might come to conclusion: we have e-mail address, just by finding out it is not null. But then later on, when trying to send e-mail I'll come to contradictory conclusion: no, we don't have e-mail address, that @!#$ Database must have been lying! Is there any logical scenario in which an empty string '' could be such a good carrier of important information (besides value and no value), which would be troublesome/inefficient to store by any other way (like additional column). I've seen many posts claiming that sometimes it's good to use empty string along with real values and NULLs, but so far haven't seen a scenario that would be logical (in terms of SQL/DB design). P.S. Some people will be tempted to answer, that it is just a matter of personal taste. I don't agree. To me it is a design decision with important consequences. So i'd like to see answers where opion about this is backed by some logical and/or technical reasons.

  Read the article

• SharePoint 2010 Hosting :: How to Create an External Content Type SharePoint 2010

  - by mbridge

  In this simple Article trying to show how SharePoint Designer 2010 more the External Content Type to External Database are very easy to create and can be integrated with our SharePoint Portals. You can download SharePoint Designer 2010 here: http://www.microsoft.com/downloads/en/details.aspx?FamilyID=d88a1505-849b-4587-b854-a7054ee28d66&displaylang=en For this Example I will create a Database in SQL Server and will use SharePoint Designer 2010 to create the connections and use as a mirror from our SharePoint Portal using List and the Database. The first thing we need to do, is connect to SQL Server and create our Database call “Contacts” and add the Table “Contact” with the following fields.  When we create the External Content Type. We  will need to associate the Content Type, in this case i am using the Generic List, then we can create the Connection to the external Data Source. After create the Connection to the Database we can define what Columns we will use and what operations we will add our custom List. For this example i select all Operation they came default. This operation are very important because the Business rules are defined in each operation. After we create the diferent operations we can create the Custom List and define the how will be the Operation and add the Name for our custom List.  If you try to access the New Custom List Call “Custom Contact” you will see we will not have access to the Business Data Connectivity. To Resolve this issue we will need to give Access and permissions to users to the Custom External Content Type BDC connection in the Central administration.  Access to Central Administration Page and select the option “Service Application Tab> Manage Service Application”. There you select the Service “Business Data Connectivity Service” then select “Manage”.  This Option will list all External Content Type, choose the External Content Type we create and select the option “Set Object Permission”, this option will allow to add users to the BDC and manage the permissions to the Custom List.  After the correct permissions are given we can Access to Data on our custom Contact List and start creating new Item and all the other options and operation we define to the same List.  Hope you like this litle Article about connect Database Content to SharePoint Portal using the Externa Content Types and BCS.Thank you.

  Read the article

• Register Game Object Components in Game Subsystems? (Component-based Game Object design)

  - by topright

  I'm creating a component-based game object system. Some tips: GameObject is simply a list of Components. There are GameSubsystems. For example, rendering, physics etc. Each GameSubsystem contains pointers to some of Components. GameSubsystem is a very powerful and flexible abstraction: it represents any slice (or aspect) of the game world. There is a need in a mechanism of registering Components in GameSubsystems (when GameObject is created and composed). There are 4 approaches: 1: Chain of responsibility pattern. Every Component is offered to every GameSubsystem. GameSubsystem makes a decision which Components to register (and how to organize them). For example, GameSubsystemRender can register Renderable Components. pro. Components know nothing about how they are used. Low coupling. A. We can add new GameSubsystem. For example, let's add GameSubsystemTitles that registers all ComponentTitle and guarantees that every title is unique and provides interface to quering objects by title. Of course, ComponentTitle should not be rewrited or inherited in this case. B. We can reorganize existing GameSubsystems. For example, GameSubsystemAudio, GameSubsystemRender, GameSubsystemParticleEmmiter can be merged into GameSubsystemSpatial (to place all audio, emmiter, render Components in the same hierarchy and use parent-relative transforms). con. Every-to-every check. Very innefficient. con. Subsystems know about Components. 2: Each Subsystem searches for Components of specific types. pro. Better performance than in Approach 1. con. Subsystems still know about Components. 3: Component registers itself in GameSubsystem(s). We know at compile-time that there is a GameSubsystemRenderer, so let's ComponentImageRender will call something like GameSubsystemRenderer::register(ComponentRenderBase*). pro. Performance. No unnecessary checks as in Approach 1. con. Components are badly coupled with GameSubsystems. 4: Mediator pattern. GameState (that contains GameSubsystems) can implement registerComponent(Component*). pro. Components and GameSubystems know nothing about each other. con. In C++ it would look like ugly and slow typeid-switch. Questions: Which approach is better and mostly used in component-based design? What Practice says? Any suggestions about implementation of Approach 4? Thank you.

  Read the article

• Why enumerator structs are a really bad idea (redux)

  - by Simon Cooper

  My previous blog post went into some detail as to why calling MoveNext on a BCL generic collection enumerator didn't quite do what you thought it would. This post covers the Reset method. To recap, here's the simple wrapper around a linked list enumerator struct from my previous post (minus the readonly on the enumerator variable): sealed class EnumeratorWrapper : IEnumerator<int> { private LinkedList<int>.Enumerator m_Enumerator; public EnumeratorWrapper(LinkedList<int> linkedList) { m_Enumerator = linkedList.GetEnumerator(); } public int Current { get { return m_Enumerator.Current; } } object System.Collections.IEnumerator.Current { get { return Current; } } public bool MoveNext() { return m_Enumerator.MoveNext(); } public void Reset() { ((System.Collections.IEnumerator)m_Enumerator).Reset(); } public void Dispose() { m_Enumerator.Dispose(); } } If you have a look at the Reset method, you'll notice I'm having to cast to IEnumerator to be able to call Reset on m_Enumerator. This is because the implementation of LinkedList<int>.Enumerator.Reset, and indeed of all the other Reset methods on the BCL generic collection enumerators, is an explicit interface implementation. However, IEnumerator is a reference type. LinkedList<int>.Enumerator is a value type. That means, in order to call the reset method at all, the enumerator has to be boxed. And the IL confirms this: .method public hidebysig newslot virtual final instance void Reset() cil managed { .maxstack 8 L_0000: nop L_0001: ldarg.0 L_0002: ldfld valuetype [System]System.Collections.Generic.LinkedList`1/Enumerator<int32> EnumeratorWrapper::m_Enumerator L_0007: box [System]System.Collections.Generic.LinkedList`1/Enumerator<int32> L_000c: callvirt instance void [mscorlib]System.Collections.IEnumerator::Reset() L_0011: nop L_0012: ret } On line 0007, we're doing a box operation, which copies the enumerator to a reference object on the heap, then on line 000c calling Reset on this boxed object. So m_Enumerator in the wrapper class is not modified by the call the Reset. And this is the only way to call the Reset method on this variable (without using reflection). Therefore, the only way that the collection enumerator struct can be used safely is to store them as a boxed IEnumerator<T>, and not use them as value types at all.

  Read the article

• What Precalculus knowledge is required before learning Discrete Math Computer Science topics?

  - by Ein Doofus

  Below I've listed the chapters from a Precalculus book as well as the author recommended Computer Science chapters from a Discrete Mathematics book. Although these chapters are from two specific books on these subjects I believe the topics are generally the same between any Precalc or Discrete Math book. What Precalculus topics should one know before starting these Discrete Math Computer Science topics?: Discrete Mathematics CS Chapters 1.1 Propositional Logic 1.2 Propositional Equivalences 1.3 Predicates and Quantifiers 1.4 Nested Quantifiers 1.5 Rules of Inference 1.6 Introduction to Proofs 1.7 Proof Methods and Strategy 2.1 Sets 2.2 Set Operations 2.3 Functions 2.4 Sequences and Summations 3.1 Algorithms 3.2 The Growths of Functions 3.3 Complexity of Algorithms 3.4 The Integers and Division 3.5 Primes and Greatest Common Divisors 3.6 Integers and Algorithms 3.8 Matrices 4.1 Mathematical Induction 4.2 Strong Induction and Well-Ordering 4.3 Recursive Definitions and Structural Induction 4.4 Recursive Algorithms 4.5 Program Correctness 5.1 The Basics of Counting 5.2 The Pigeonhole Principle 5.3 Permutations and Combinations 5.6 Generating Permutations and Combinations 6.1 An Introduction to Discrete Probability 6.4 Expected Value and Variance 7.1 Recurrence Relations 7.3 Divide-and-Conquer Algorithms and Recurrence Relations 7.5 Inclusion-Exclusion 8.1 Relations and Their Properties 8.2 n-ary Relations and Their Applications 8.3 Representing Relations 8.5 Equivalence Relations 9.1 Graphs and Graph Models 9.2 Graph Terminology and Special Types of Graphs 9.3 Representing Graphs and Graph Isomorphism 9.4 Connectivity 9.5 Euler and Hamilton Ptahs 10.1 Introduction to Trees 10.2 Application of Trees 10.3 Tree Traversal 11.1 Boolean Functions 11.2 Representing Boolean Functions 11.3 Logic Gates 11.4 Minimization of Circuits 12.1 Language and Grammars 12.2 Finite-State Machines with Output 12.3 Finite-State Machines with No Output 12.4 Language Recognition 12.5 Turing Machines Precalculus Chapters R.1 The Real-Number System R.2 Integer Exponents, Scientific Notation, and Order of Operations R.3 Addition, Subtraction, and Multiplication of Polynomials R.4 Factoring R.5 Rational Expressions R.6 Radical Notation and Rational Exponents R.7 The Basics of Equation Solving 1.1 Functions, Graphs, Graphers 1.2 Linear Functions, Slope, and Applications 1.3 Modeling: Data Analysis, Curve Fitting, and Linear Regression 1.4 More on Functions 1.5 Symmetry and Transformations 1.6 Variation and Applications 1.7 Distance, Midpoints, and Circles 2.1 Zeros of Linear Functions and Models 2.2 The Complex Numbers 2.3 Zeros of Quadratic Functions and Models 2.4 Analyzing Graphs of Quadratic Functions 2.5 Modeling: Data Analysis, Curve Fitting, and Quadratic Regression 2.6 Zeros and More Equation Solving 2.7 Solving Inequalities 3.1 Polynomial Functions and Modeling 3.2 Polynomial Division; The Remainder and Factor Theorems 3.3 Theorems about Zeros of Polynomial Functions 3.4 Rational Functions 3.5 Polynomial and Rational Inequalities 4.1 Composite and Inverse Functions 4.2 Exponential Functions and Graphs 4.3 Logarithmic Functions and Graphs 4.4 Properties of Logarithmic Functions 4.5 Solving Exponential and Logarithmic Equations 4.6 Applications and Models: Growth and Decay 5.1 Systems of Equations in Two Variables 5.2 System of Equations in Three Variables 5.3 Matrices and Systems of Equations 5.4 Matrix Operations 5.5 Inverses of Matrices 5.6 System of Inequalities and Linear Programming 5.7 Partial Fractions 6.1 The Parabola 6.2 The Circle and Ellipse 6.3 The Hyperbola 6.4 Nonlinear Systems of Equations

  Read the article

< Previous Page | 545 546 547 548 549 550 551 552 553 554 555 556  | Next Page >