Search Results

Search found 94227 results on 3770 pages for 'common code'.

Page 791/3770 | < Previous Page | 787 788 789 790 791 792 793 794 795 796 797 798  | Next Page >

  • Windows Phone 7 Development &ndash; Useful Links

    - by David Turner
    Here are some excellent links for anyone developing for Windows Phone 7: J.D. Meier’s Windows Phone Developer Guidance Map – this is immense.  Also check out the Silverlight version Justin Angel’s site – some really great articles on unlocked roms, automation and Continuous Integration Windows Phone 7 Development Best Practices Wiki Jeff Blankenburg’s 31 days of Windows Phone 7 This post of Links to sample code for Windows Phone Tim Heuers blog, particularly this post of Tips and Tricks Kevin Marshall's blog, particularly the epic WP7 Development Tips Part 1 post Code Samples for Windows Phone on MSDN If you have unlocked your phone for development, then you can use the WPConnect tool to connect to the device rather than using the Zune client.  I found it useful to pin a shortcut to WPConnect in my Start Menu. The Performance Counters displayed when you debug your app on a device are useful for seeing things like frame rate and memory usage, this page on MSDN explains what the numbers mean.  Jeff Blankenburg covers this in more details on his blog I also came across this set of links to tutorials recently which looks very useful. Creating Windows Phone 7 Application and Marketplace Icons: http://expression.microsoft.com/en-us/gg317447.aspx

    Read the article

  • Help with creating symbolic link

    - by user1737794
    I'm a little bit confused with how the symbolic links work. I hope someone can guide me in the right direction. I want to put a demo online from our software, which normally only runs locally on a Mac Mini. So I put all the files in the var/www from my Ubuntu 12.04 server installation. There are a lot of hardcoded links in the software which point to "/Applications/XAMPP/xamppfiles/htdocs/narrowcasting" Of course I can change all these code on my html/php files in /var/www, but that would be quite annoying. I hope I can fix this by creating a symbolic link. For example I have a directory called thumb in /var/www/thumb. The php code is trying to put a image in /Applications/XAMPP/xamppfiles/htdocs/narrowcasting/thumb. Can anyone give me a tip how to achieve this with a symbolic link? Thanks in advance.

    Read the article

  • Beware of const members

    - by nmarun
    I happened to learn a new thing about const today and how one needs to be careful with its usage. Let’s say I have a third-party assembly ‘ConstVsReadonlyLib’ with a class named ConstSideEffect.cs: 1: public class ConstSideEffect 2: { 3: public static readonly int StartValue = 10; 4: public const int EndValue = 20; 5: } In my project, I reference the above assembly as follows: 1: static void Main(string[] args) 2: { 3: for (int i = ConstSideEffect.StartValue; i < ConstSideEffect.EndValue; i++) 4: { 5: Console.WriteLine(i); 6: } 7: Console.ReadLine(); 8: } You’ll see values 10 through 19 as expected. Now, let’s say I receive a new version of the ConstVsReadonlyLib. 1: public class ConstSideEffect 2: { 3: public static readonly int StartValue = 5; 4: public const int EndValue = 30; 5: } If I just drop this new assembly in the bin folder and run the application, without rebuilding my console application, my thinking was that the output would be from 5 to 29. Of course I was wrong… if not you’d not be reading this blog. The actual output is from 5 through 19. The reason is due to the behavior of const and readonly members. To begin with, const is the compile-time constant and readonly is a runtime constant. Next, when you compile the code, a compile-time constant member is replaced with the value of the constant in the code. But, the IL generated when you reference a read-only constant, references the readonly variable, not its value. So, the IL version of the Main method, after compilation actually looks something like: 1: static void Main(string[] args) 2: { 3: for (int i = ConstSideEffect.StartValue; i < 20; i++) 4: { 5: Console.WriteLine(i); 6: } 7: Console.ReadLine(); 8: } I’m no expert with this IL thingi, but when I look at the disassembled code of the exe file (using IL Disassembler), I see the following: I see our readonly member still being referenced by the variable name (ConstVsReadonlyLib.ConstSideEffect::StartValue) in line 0001. Then there’s the Console.WriteLine in line 000b and finally, see the value of 20 in line 0017. This, I’m pretty sure is our const member being replaced by its value which marks the upper bound of the ‘for’ loop. Now you know why the output was from 5 through 19. This definitely is a side-effect of having const members and one needs to be aware of it. While we’re here, I’d like to add a few other points about const and readonly members: const is slightly faster, but is less flexible readonly cannot be declared within a method scope const can be used only on primitive types (numbers and strings) Just wanted to share this before going to bed!

    Read the article

  • Approach on working with many programmers on one module/feature

    - by Panoy
    How can 2 or more developers code a certain feature/module of a software? Let's assume that the module is big and feature rich. How would they prevent each other from overlapping their code? Say, we have the same method but is implemented in a different way. Do you think it might be better to have one focused at a specific feature only? Is a version control system like Git would help solve the problem? Is it correct that it allows developers to have these "branches" and then merge it later on? What's your take on this?

    Read the article

  • Performance tracking/monitoring in games

    - by vitaliy kotik
    Let's say I have an online game with a downloadable client / browser plugin. I want to track performance of my software and automatically send summary to the server. Let it be fps, latency, load time, physics step calc. time, whatever... I also want tools to perform data analysis: per session stats, per hardware stats, avgs, totals, diagrams, etc. So that I could see what are the real world hotspots / bottlenecks. Is there any common out-of-the-box / SaS solution?

    Read the article

  • Question about Target parameter of Matrix.CreateLookAt

    - by manning18
    I have a newbie question that's causing me a little bit of confusion when experimenting with cameras and reading other peoples implementations - does this parameter represent a point or a vector? In some examples I've seen people treat it like a specific point they are looking at (eg a position in the world), other times I see people caching the orientation of the camera in a rotation matrix and simply using the Matrix.Forward property as the "target", and other times it's a vector that's the result of targetPos - camPos and also I saw a camPos + orientation.Forward I was also just playing around with hard-coded target positions with same direction eg 1 to 10000 with no discernible difference in what I saw in the scene. Is the "Target" parameter actually a position or a direction (irrespective of magnitude)? Are there any subtle differences in behaviors, common mistakes or gotchas that are associated with what values you provide, or HOW you provide this paramter? Are all the methods I mentioned above equivalent? (sorry, I've only recently started and my math is still catching up)

    Read the article

  • Setting up CLASSPATH and ant in Ubuntu

    - by Dzung Nguyen
    I just started to learn Java using Thinking in Java book, and have some troubles using ant. I'm using Ubuntu 12.04, and have openjdk 7 java installed. I also setup the CLASSPATH to be the code folder When I run ant in code folder, this is the output: Exception in thread "main" java.lang.RuntimeException: JDK 1.4.1 or higher is required to run the examples in this book. [CheckVersion] at com.bruceeckel.tools.CheckVersion.main(Unknown Source) However when I run java -version, this is the output: java version "1.6.0_27" OpenJDK Runtime Environment (IcedTea6 1.12.5) (6b27-1.12.5-0ubuntu0.12.04.1) OpenJDK 64-Bit Server VM (build 20.0-b12, mixed mode) How to setup ant and classpath correctly?

    Read the article

  • Best C# database communication technique

    - by user65439
    A few days ago I read a reply to a question where people said that the days of writing queries within your c# code are long gone. I'm not sure what the specific person meant with the comment but it got me thinking. At the company I'm currently working at we maintain an assembly containing all the queries to the database (let's call it Queries), this assembly is reference by a QueryService (Retrieve the correct queries) assembly which in turn is referenced by a UnitOfWork assembly (The database connector classes, we have different connector classes for SQL, MySQL etc.). We use these three assemblies to perform operations on our database and all queries/commands are written in our C# code. Is there a better way to communicate with the database and is there a better way to communicate with different database types?

    Read the article

  • Theoretically bug-free programs

    - by user2443423
    I have read lot of articles which state that code can't be bug-free, and they are talking about these theorems: Halting problem Gödel's incompleteness theorem Rice's theorem Actually Rice's theorem looks like an implication of the halting problem and the halting problem is in close relationship with Gödel's incompleteness theorem. Does this imply that every program will have at least one unintended behavior? Or does it mean that it's not possible to write code to verify it? What about recursive checking? Let's assume that I have two programs. Both of them have bugs, but they don't share the same bug. What will happen if I run them concurrently? And of course most of discussions talked about Turing machines. What about linear-bounded automation (real computers)?

    Read the article

  • Simple heart container script for 2D game (Unity)?

    - by N1ghtshade3
    I'm attempting to create a simple mobile game (C#) that involves a simple three-heart life system. After searching for hours online, many of the solutions use OnGUI (which is apparently horrible for performance) and the rest are too complicated for me to understand and add to my code. The other solutions involve using a single texture and just hiding part of it when damage is taken. In my game, however, the player should be able to go over three hearts (for example, every 100 points). Sebastian Lague's Zelda-Style Health is what I'm looking for, but even though it's a tutorial there is way too much going on that I don't need or can't customize to fit in mine. What I have so far is a script called HealthScript.cs which contains a variable lives. I have another script, PlayerPhysics.cs which calls HealthScript and subtracts a life when an enemy is hit. The part I don't get is actually drawing the hearts. I think I understand what needs to happen, I just am not experienced enough with Unity to know how. The Start function should draw three (or whatever lives is set to) hearts in the top right corner. Since the game should be resolution-independent to accommodate the various sizes of Android devices, I'd rather use scaling rather than PixelInset. When the player hits an enemy as detected by PlayerPhysics.cs, it should subtract from lives. I think that I have this working using this.GetComponent<HealthScript>().lives -= 1 but I'm not sure if it actually works. This should trigger a redraw of the hearts so that there are now two hearts. The same principle would apply for adding hearts when a score is reached, except when lives > maxHeartsPerRow, the new hearts should be drawn below the old ones. I realise I don't have much code to show but believe me; I've tried for quite some time to figure this out and have little to show for it. Any help at all would be welcome; it seems like it shouldn't take that much code to put an image on the screen for each life there is, but I haven't found anything yet. Thanks!

    Read the article

  • Part 1: What are EBS Customizations?

    - by volker.eckardt(at)oracle.com
    Everything what is not shipped as Oracle standard may be called customization. And very often we differentiate between setup and customization, although setup can also be required when working with customizations.This highlights one of the first challenges, because someone needs to track setup brought over with customizations and this needs to be synchronized with the (standard) setup done manually. This is not only a tracking issue, but also a documentation issue. I will cover this in one of the following blogs in more detail.But back to the topic itself. Mainly our code pieces (java, pl/sql, sql, shell scripts), custom objects (tables, views, packages etc.) and application objects (concurrent programs, lookups, forms, reports, OAF pages etc.) are treated as customizations. In general we define two types: customization by extension and customization by modification. For sure we like to minimize standard code modifications, but sometimes it is just not possible to provide a certain functionality without doing it.Keep in mind that the EBS provides a number of alternatives for modifications, just to mention some:Files in file system    add your custom top before the standard top to the pathBI Publisher Report    add a custom layout and disable the standard layout, automatically yours will be taken.Form /OAF Change    use personalization or substitutionUsing such techniques you are on the safe site regarding standard patches, but for sure a retest is always required!Many customizations are growing over the time, initially it was just one file, but in between we have 5, 10 or 15 files in our customization pack. The more files you have, the more important is the installation order.Last but not least also personalization's are treated as customizations, although you may not use any deployment pack to transfer such personalisation's (but you can). For OAF personalization's you can use iSetup, I have also enabled iSetup to allow Forms personalizations to transport.Interfaces and conversion objects are quite often also categorized as customizations and I promote this decision. Your development standards are related to all these kinds of custom code whether we are exchanging data with users (via form or report) or with other systems (via inbound or outbound interface).To cover all these types of customizations two acronyms have been defined: RICE and CEMLI.RICE = Reports, Interfaces, Conversions, and ExtensionsCEMLI = Customization, Extension, Modification, Localization, IntegrationThe word CEMLI has been introduced by Oracle On Demand and is used within Oracle projects quite often, but also RICE is well known as acronym.It doesn't matter which acronym you are using, the main task here is to classify and categorize your customizations to allow everyone to understand when you talk about RICE- 211, CEMLI XXFI_BAST or XXOM_RPT_030.Side note: Such references are not automatically objects prefixes, but they are often used as such. I plan also to address this point in one other blog.Thank you!Volker

    Read the article

  • Building a Flash Platformer

    - by Jonathan O
    I am basically making a game where the whole game is run in the onEnterFrame method. This is causing a delay in my code that makes debugging and testing difficult. Should programming an entire platformer in this method be efficient enough for me to run hundreds of lines of code? Also, do variables in flash get updated immediately? Are there just lots of threads listening at the same time? Here is the code... stage.addEventListener(Event.ENTER_FRAME, onEnter); function onEnter(e:Event):void { //Jumping if (Yoshi.y > groundBaseLevel) { dy = 0; canJump = true; onGround = true; //This line is not updated in time } if (Key.isDown(Key.UP) && canJump) { dy = -10; canJump = false; onGround = false; //This line is not updated in time } if(!onGround) { dy += gravity; Yoshi.y += dy; } //limit screen boundaries //character movement if (! Yoshi.hitTestObject(Platform)) //no collision detected { if (Key.isDown(Key.RIGHT)) { speed += 4; speed *= friction; Yoshi.x = Yoshi.x + movementIncrement + speed; Yoshi.scaleX = 1; Yoshi.gotoAndStop('Walking'); } else if (Key.isDown(Key.LEFT)) { speed -= 4; speed *= friction; Yoshi.x = Yoshi.x - movementIncrement + speed; Yoshi.scaleX = -1; Yoshi.gotoAndStop('Walking'); } else { speed *= friction; Yoshi.x = Yoshi.x + speed; Yoshi.gotoAndStop('Still'); } } else //bounce back collision detected { if(Yoshi.hitTestPoint(Platform.x - Platform.width/2, Platform.y - Platform.height/2, false)) { trace('collision left'); Yoshi.x -=20; } if(Yoshi.hitTestPoint(Platform.x, Platform.y - Platform.height/2, false)) { trace('collision top'); onGround=true; //This update is not happening in time speed = 0; } } }

    Read the article

  • C#/.NET Little Wonders: The Generic Func Delegates

    - by James Michael Hare
    Once again, in this series of posts I look at the parts of the .NET Framework that may seem trivial, but can help improve your code by making it easier to write and maintain. The index of all my past little wonders posts can be found here. Back in one of my three original “Little Wonders” Trilogy of posts, I had listed generic delegates as one of the Little Wonders of .NET.  Later, someone posted a comment saying said that they would love more detail on the generic delegates and their uses, since my original entry just scratched the surface of them. Last week, I began our look at some of the handy generic delegates built into .NET with a description of delegates in general, and the Action family of delegates.  For this week, I’ll launch into a look at the Func family of generic delegates and how they can be used to support generic, reusable algorithms and classes. Quick Delegate Recap Delegates are similar to function pointers in C++ in that they allow you to store a reference to a method.  They can store references to either static or instance methods, and can actually be used to chain several methods together in one delegate. Delegates are very type-safe and can be satisfied with any standard method, anonymous method, or a lambda expression.  They can also be null as well (refers to no method), so care should be taken to make sure that the delegate is not null before you invoke it. Delegates are defined using the keyword delegate, where the delegate’s type name is placed where you would typically place the method name: 1: // This delegate matches any method that takes string, returns nothing 2: public delegate void Log(string message); This delegate defines a delegate type named Log that can be used to store references to any method(s) that satisfies its signature (whether instance, static, lambda expression, etc.). Delegate instances then can be assigned zero (null) or more methods using the operator = which replaces the existing delegate chain, or by using the operator += which adds a method to the end of a delegate chain: 1: // creates a delegate instance named currentLogger defaulted to Console.WriteLine (static method) 2: Log currentLogger = Console.Out.WriteLine; 3:  4: // invokes the delegate, which writes to the console out 5: currentLogger("Hi Standard Out!"); 6:  7: // append a delegate to Console.Error.WriteLine to go to std error 8: currentLogger += Console.Error.WriteLine; 9:  10: // invokes the delegate chain and writes message to std out and std err 11: currentLogger("Hi Standard Out and Error!"); While delegates give us a lot of power, it can be cumbersome to re-create fairly standard delegate definitions repeatedly, for this purpose the generic delegates were introduced in various stages in .NET.  These support various method types with particular signatures. Note: a caveat with generic delegates is that while they can support multiple parameters, they do not match methods that contains ref or out parameters. If you want to a delegate to represent methods that takes ref or out parameters, you will need to create a custom delegate. We’ve got the Func… delegates Just like it’s cousin, the Action delegate family, the Func delegate family gives us a lot of power to use generic delegates to make classes and algorithms more generic.  Using them keeps us from having to define a new delegate type when need to make a class or algorithm generic. Remember that the point of the Action delegate family was to be able to perform an “action” on an item, with no return results.  Thus Action delegates can be used to represent most methods that take 0 to 16 arguments but return void.  You can assign a method The Func delegate family was introduced in .NET 3.5 with the advent of LINQ, and gives us the power to define a function that can be called on 0 to 16 arguments and returns a result.  Thus, the main difference between Action and Func, from a delegate perspective, is that Actions return nothing, but Funcs return a result. The Func family of delegates have signatures as follows: Func<TResult> – matches a method that takes no arguments, and returns value of type TResult. Func<T, TResult> – matches a method that takes an argument of type T, and returns value of type TResult. Func<T1, T2, TResult> – matches a method that takes arguments of type T1 and T2, and returns value of type TResult. Func<T1, T2, …, TResult> – and so on up to 16 arguments, and returns value of type TResult. These are handy because they quickly allow you to be able to specify that a method or class you design will perform a function to produce a result as long as the method you specify meets the signature. For example, let’s say you were designing a generic aggregator, and you wanted to allow the user to define how the values will be aggregated into the result (i.e. Sum, Min, Max, etc…).  To do this, we would ask the user of our class to pass in a method that would take the current total, the next value, and produce a new total.  A class like this could look like: 1: public sealed class Aggregator<TValue, TResult> 2: { 3: // holds method that takes previous result, combines with next value, creates new result 4: private Func<TResult, TValue, TResult> _aggregationMethod; 5:  6: // gets or sets the current result of aggregation 7: public TResult Result { get; private set; } 8:  9: // construct the aggregator given the method to use to aggregate values 10: public Aggregator(Func<TResult, TValue, TResult> aggregationMethod = null) 11: { 12: if (aggregationMethod == null) throw new ArgumentNullException("aggregationMethod"); 13:  14: _aggregationMethod = aggregationMethod; 15: } 16:  17: // method to add next value 18: public void Aggregate(TValue nextValue) 19: { 20: // performs the aggregation method function on the current result and next and sets to current result 21: Result = _aggregationMethod(Result, nextValue); 22: } 23: } Of course, LINQ already has an Aggregate extension method, but that works on a sequence of IEnumerable<T>, whereas this is designed to work more with aggregating single results over time (such as keeping track of a max response time for a service). We could then use this generic aggregator to find the sum of a series of values over time, or the max of a series of values over time (among other things): 1: // creates an aggregator that adds the next to the total to sum the values 2: var sumAggregator = new Aggregator<int, int>((total, next) => total + next); 3:  4: // creates an aggregator (using static method) that returns the max of previous result and next 5: var maxAggregator = new Aggregator<int, int>(Math.Max); So, if we were timing the response time of a web method every time it was called, we could pass that response time to both of these aggregators to get an idea of the total time spent in that web method, and the max time spent in any one call to the web method: 1: // total will be 13 and max 13 2: int responseTime = 13; 3: sumAggregator.Aggregate(responseTime); 4: maxAggregator.Aggregate(responseTime); 5:  6: // total will be 20 and max still 13 7: responseTime = 7; 8: sumAggregator.Aggregate(responseTime); 9: maxAggregator.Aggregate(responseTime); 10:  11: // total will be 40 and max now 20 12: responseTime = 20; 13: sumAggregator.Aggregate(responseTime); 14: maxAggregator.Aggregate(responseTime); The Func delegate family is useful for making generic algorithms and classes, and in particular allows the caller of the method or user of the class to specify a function to be performed in order to generate a result. What is the result of a Func delegate chain? If you remember, we said earlier that you can assign multiple methods to a delegate by using the += operator to chain them.  So how does this affect delegates such as Func that return a value, when applied to something like the code below? 1: Func<int, int, int> combo = null; 2:  3: // What if we wanted to aggregate the sum and max together? 4: combo += (total, next) => total + next; 5: combo += Math.Max; 6:  7: // what is the result? 8: var comboAggregator = new Aggregator<int, int>(combo); Well, in .NET if you chain multiple methods in a delegate, they will all get invoked, but the result of the delegate is the result of the last method invoked in the chain.  Thus, this aggregator would always result in the Math.Max() result.  The other chained method (the sum) gets executed first, but it’s result is thrown away: 1: // result is 13 2: int responseTime = 13; 3: comboAggregator.Aggregate(responseTime); 4:  5: // result is still 13 6: responseTime = 7; 7: comboAggregator.Aggregate(responseTime); 8:  9: // result is now 20 10: responseTime = 20; 11: comboAggregator.Aggregate(responseTime); So remember, you can chain multiple Func (or other delegates that return values) together, but if you do so you will only get the last executed result. Func delegates and co-variance/contra-variance in .NET 4.0 Just like the Action delegate, as of .NET 4.0, the Func delegate family is contra-variant on its arguments.  In addition, it is co-variant on its return type.  To support this, in .NET 4.0 the signatures of the Func delegates changed to: Func<out TResult> – matches a method that takes no arguments, and returns value of type TResult (or a more derived type). Func<in T, out TResult> – matches a method that takes an argument of type T (or a less derived type), and returns value of type TResult(or a more derived type). Func<in T1, in T2, out TResult> – matches a method that takes arguments of type T1 and T2 (or less derived types), and returns value of type TResult (or a more derived type). Func<in T1, in T2, …, out TResult> – and so on up to 16 arguments, and returns value of type TResult (or a more derived type). Notice the addition of the in and out keywords before each of the generic type placeholders.  As we saw last week, the in keyword is used to specify that a generic type can be contra-variant -- it can match the given type or a type that is less derived.  However, the out keyword, is used to specify that a generic type can be co-variant -- it can match the given type or a type that is more derived. On contra-variance, if you are saying you need an function that will accept a string, you can just as easily give it an function that accepts an object.  In other words, if you say “give me an function that will process dogs”, I could pass you a method that will process any animal, because all dogs are animals.  On the co-variance side, if you are saying you need a function that returns an object, you can just as easily pass it a function that returns a string because any string returned from the given method can be accepted by a delegate expecting an object result, since string is more derived.  Once again, in other words, if you say “give me a method that creates an animal”, I can pass you a method that will create a dog, because all dogs are animals. It really all makes sense, you can pass a more specific thing to a less specific parameter, and you can return a more specific thing as a less specific result.  In other words, pay attention to the direction the item travels (parameters go in, results come out).  Keeping that in mind, you can always pass more specific things in and return more specific things out. For example, in the code below, we have a method that takes a Func<object> to generate an object, but we can pass it a Func<string> because the return type of object can obviously accept a return value of string as well: 1: // since Func<object> is co-variant, this will access Func<string>, etc... 2: public static string Sequence(int count, Func<object> generator) 3: { 4: var builder = new StringBuilder(); 5:  6: for (int i=0; i<count; i++) 7: { 8: object value = generator(); 9: builder.Append(value); 10: } 11:  12: return builder.ToString(); 13: } Even though the method above takes a Func<object>, we can pass a Func<string> because the TResult type placeholder is co-variant and accepts types that are more derived as well: 1: // delegate that's typed to return string. 2: Func<string> stringGenerator = () => DateTime.Now.ToString(); 3:  4: // This will work in .NET 4.0, but not in previous versions 5: Sequence(100, stringGenerator); Previous versions of .NET implemented some forms of co-variance and contra-variance before, but .NET 4.0 goes one step further and allows you to pass or assign an Func<A, BResult> to a Func<Y, ZResult> as long as A is less derived (or same) as Y, and BResult is more derived (or same) as ZResult. Sidebar: The Func and the Predicate A method that takes one argument and returns a bool is generally thought of as a predicate.  Predicates are used to examine an item and determine whether that item satisfies a particular condition.  Predicates are typically unary, but you may also have binary and other predicates as well. Predicates are often used to filter results, such as in the LINQ Where() extension method: 1: var numbers = new[] { 1, 2, 4, 13, 8, 10, 27 }; 2:  3: // call Where() using a predicate which determines if the number is even 4: var evens = numbers.Where(num => num % 2 == 0); As of .NET 3.5, predicates are typically represented as Func<T, bool> where T is the type of the item to examine.  Previous to .NET 3.5, there was a Predicate<T> type that tended to be used (which we’ll discuss next week) and is still supported, but most developers recommend using Func<T, bool> now, as it prevents confusion with overloads that accept unary predicates and binary predicates, etc.: 1: // this seems more confusing as an overload set, because of Predicate vs Func 2: public static SomeMethod(Predicate<int> unaryPredicate) { } 3: public static SomeMethod(Func<int, int, bool> binaryPredicate) { } 4:  5: // this seems more consistent as an overload set, since just uses Func 6: public static SomeMethod(Func<int, bool> unaryPredicate) { } 7: public static SomeMethod(Func<int, int, bool> binaryPredicate) { } Also, even though Predicate<T> and Func<T, bool> match the same signatures, they are separate types!  Thus you cannot assign a Predicate<T> instance to a Func<T, bool> instance and vice versa: 1: // the same method, lambda expression, etc can be assigned to both 2: Predicate<int> isEven = i => (i % 2) == 0; 3: Func<int, bool> alsoIsEven = i => (i % 2) == 0; 4:  5: // but the delegate instances cannot be directly assigned, strongly typed! 6: // ERROR: cannot convert type... 7: isEven = alsoIsEven; 8:  9: // however, you can assign by wrapping in a new instance: 10: isEven = new Predicate<int>(alsoIsEven); 11: alsoIsEven = new Func<int, bool>(isEven); So, the general advice that seems to come from most developers is that Predicate<T> is still supported, but we should use Func<T, bool> for consistency in .NET 3.5 and above. Sidebar: Func as a Generator for Unit Testing One area of difficulty in unit testing can be unit testing code that is based on time of day.  We’d still want to unit test our code to make sure the logic is accurate, but we don’t want the results of our unit tests to be dependent on the time they are run. One way (of many) around this is to create an internal generator that will produce the “current” time of day.  This would default to returning result from DateTime.Now (or some other method), but we could inject specific times for our unit testing.  Generators are typically methods that return (generate) a value for use in a class/method. For example, say we are creating a CacheItem<T> class that represents an item in the cache, and we want to make sure the item shows as expired if the age is more than 30 seconds.  Such a class could look like: 1: // responsible for maintaining an item of type T in the cache 2: public sealed class CacheItem<T> 3: { 4: // helper method that returns the current time 5: private static Func<DateTime> _timeGenerator = () => DateTime.Now; 6:  7: // allows internal access to the time generator 8: internal static Func<DateTime> TimeGenerator 9: { 10: get { return _timeGenerator; } 11: set { _timeGenerator = value; } 12: } 13:  14: // time the item was cached 15: public DateTime CachedTime { get; private set; } 16:  17: // the item cached 18: public T Value { get; private set; } 19:  20: // item is expired if older than 30 seconds 21: public bool IsExpired 22: { 23: get { return _timeGenerator() - CachedTime > TimeSpan.FromSeconds(30.0); } 24: } 25:  26: // creates the new cached item, setting cached time to "current" time 27: public CacheItem(T value) 28: { 29: Value = value; 30: CachedTime = _timeGenerator(); 31: } 32: } Then, we can use this construct to unit test our CacheItem<T> without any time dependencies: 1: var baseTime = DateTime.Now; 2:  3: // start with current time stored above (so doesn't drift) 4: CacheItem<int>.TimeGenerator = () => baseTime; 5:  6: var target = new CacheItem<int>(13); 7:  8: // now add 15 seconds, should still be non-expired 9: CacheItem<int>.TimeGenerator = () => baseTime.AddSeconds(15); 10:  11: Assert.IsFalse(target.IsExpired); 12:  13: // now add 31 seconds, should now be expired 14: CacheItem<int>.TimeGenerator = () => baseTime.AddSeconds(31); 15:  16: Assert.IsTrue(target.IsExpired); Now we can unit test for 1 second before, 1 second after, 1 millisecond before, 1 day after, etc.  Func delegates can be a handy tool for this type of value generation to support more testable code.  Summary Generic delegates give us a lot of power to make truly generic algorithms and classes.  The Func family of delegates is a great way to be able to specify functions to calculate a result based on 0-16 arguments.  Stay tuned in the weeks that follow for other generic delegates in the .NET Framework!   Tweet Technorati Tags: .NET, C#, CSharp, Little Wonders, Generics, Func, Delegates

    Read the article

  • How to incorporate existing open source software from a licensing perspective?

    - by Matt
    I'm working on software that uses the following libraries: Biopython SciPy NumPy All of the above have licenses similar to MIT or BSD. Three scenarios: First, if I don't redistribute those dependencies, and only my code, then all I need is my own copyright and license (planing on using the MIT License) for my code. Correct? What if I use py2exe or py2app to create a binary executable to distribute so as to make it easy for people to run the application without needing to install python and all the dependencies. Of course this also means that my binary file(s) contains python itself (along with any other packages I might have performed a pip install xyz). What if I bundle Biopython, SciPy, and NumPy binaries in my package? In the latter two cases, what do I need to do to comply with copyright laws.

    Read the article

  • Is the slow performance of programming languages a bad thing?

    - by Emanuil
    Here's how I see it. There's machine code and it's all that the computers needs in order to run something. The computers don't care about programming languages. It doesn't matter to them if the machine code comes from Perl, Python or PHP. Programming languages exist to serve programmers. Some programming languages run slower than others but that's not necessarily because there is something wrong with them. In many cases it's just because they do more things that otherwise programmers would have to do and by doing these things, they do better what they are supposed to do - serve programmers. So is the slower performance (at runtime) of a programming language really a bad thing?

    Read the article

  • How Microwave Ovens Work [Video]

    - by Jason Fitzpatrick
    In this informative how-it-works video, we’re treated to a peek inside the common microwave and the science behind the magnetron that powers it. Bill details how a microwave oven heats food. He describes how the microwave vacuum tube, called a magnetron, generates radio frequencies that cause the water in food to rotate back and forth. He shows the standing wave inside the oven, and notes how you can measure the wavelength with melted cheese. He concludes by describing how a magnetron generates radio waves. [via Make] How to Banish Duplicate Photos with VisiPic How to Make Your Laptop Choose a Wired Connection Instead of Wireless HTG Explains: What Is Two-Factor Authentication and Should I Be Using It?

    Read the article

  • OpenJDK pour MacOS : le projet a débuté, les premiers codes sont disponibles

    OpenJDK pour MacOS : le projet a débuté Les premiers codes sont disponibles Mise à jour du 13/01/2011 par Idelways Les premiers codes de la version pour MacOS X du Java Development Kit 7 (dans le cadre du projet OpenJDK) sont disponibles. Il s'agit du port d'un code initial destiné à BSD (UNIX). Ce code est téléchargeable sur le site de OpenJDK, dans le projet « MacOS X Port ». Une mailing-list et un wiki ont également été ajouté, et bientôt un gestionnaire de rapports de bugs Pour mémoire, Apple avait provoqué un vent de panique dans la communauté Java en déclarant à la mi-novembre 2010 qu'il ne comptait...

    Read the article

  • Integration Patterns with Azure Service Bus Relay, Part 2: Anonymous full-trust .NET consumer

    - by Elton Stoneman
    This is the second in the IPASBR series, see also: Integration Patterns with Azure Service Bus Relay, Part 1: Exposing the on-premise service Part 2 is nice and easy. From Part 1 we exposed our service over the Azure Service Bus Relay using the netTcpRelayBinding and verified we could set up our network to listen for relayed messages. Assuming we want to consume that service in .NET from an environment which is fairly unrestricted for us, but quite restricted for attackers, we can use netTcpRelay and shared secret authentication. Pattern applicability This is a good fit for scenarios where: the consumer can run .NET in full trust the environment does not restrict use of external DLLs the runtime environment is secure enough to keep shared secrets the service does not need to know who is consuming it the service does not need to know who the end-user is So for example, the consumer is an ASP.NET website sitting in a cloud VM or Azure worker role, where we can keep the shared secret in web.config and we don't need to flow any identity through to the on-premise service. The service doesn't care who the consumer or end-user is - say it's a reference data service that provides a list of vehicle manufacturers. Provided you can authenticate with ACS and have access to Service Bus endpoint, you can use the service and it doesn't care who you are. In this post, we’ll consume the service from Part 1 in ASP.NET using netTcpRelay. The code for Part 2 (+ Part 1) is on GitHub here: IPASBR Part 2 Authenticating and authorizing with ACS In this scenario the consumer is a server in a controlled environment, so we can use a shared secret to authenticate with ACS, assuming that there is governance around the environment and the codebase which will prevent the identity being compromised. From the provider's side, we will create a dedicated service identity for this consumer, so we can lock down their permissions. The provider controls the identity, so the consumer's rights can be revoked. We'll add a new service identity for the namespace in ACS , just as we did for the serviceProvider identity in Part 1. I've named the identity fullTrustConsumer. We then need to add a rule to map the incoming identity claim to an outgoing authorization claim that allows the identity to send messages to Service Bus (see Part 1 for a walkthrough creating Service Idenitities): Issuer: Access Control Service Input claim type: http://schemas.xmlsoap.org/ws/2005/05/identity/claims/nameidentifier Input claim value: fullTrustConsumer Output claim type: net.windows.servicebus.action Output claim value: Send This sets up a service identity which can send messages into Service Bus, but cannot register itself as a listener, or manage the namespace. Adding a Service Reference The Part 2 sample client code is ready to go, but if you want to replicate the steps, you’re going to add a WSDL reference, add a reference to Microsoft.ServiceBus and sort out the ServiceModel config. In Part 1 we exposed metadata for our service, so we can browse to the WSDL locally at: http://localhost/Sixeyed.Ipasbr.Services/FormatService.svc?wsdl If you add a Service Reference to that in a new project you'll get a confused config section with a customBinding, and a set of unrecognized policy assertions in the namespace http://schemas.microsoft.com/netservices/2009/05/servicebus/connect. If you NuGet the ASB package (“windowsazure.servicebus”) first and add the service reference - you'll get the same messy config. Either way, the WSDL should have downloaded and you should have the proxy code generated. You can delete the customBinding entries and copy your config from the service's web.config (this is already done in the sample project in Sixeyed.Ipasbr.NetTcpClient), specifying details for the client:     <client>       <endpoint address="sb://sixeyed-ipasbr.servicebus.windows.net/net"                 behaviorConfiguration="SharedSecret"                 binding="netTcpRelayBinding"                 contract="FormatService.IFormatService" />     </client>     <behaviors>       <endpointBehaviors>         <behavior name="SharedSecret">           <transportClientEndpointBehavior credentialType="SharedSecret">             <clientCredentials>               <sharedSecret issuerName="fullTrustConsumer"                             issuerSecret="E3feJSMuyGGXksJi2g2bRY5/Bpd2ll5Eb+1FgQrXIqo="/>             </clientCredentials>           </transportClientEndpointBehavior>         </behavior>       </endpointBehaviors>     </behaviors>   The proxy is straight WCF territory, and the same client can run against Azure Service Bus through any relay binding, or directly to the local network service using any WCF binding - the contract is exactly the same. The code is simple, standard WCF stuff: using (var client = new FormatService.FormatServiceClient()) { outputString = client.ReverseString(inputString); } Running the sample First, update Solution Items\AzureConnectionDetails.xml with your service bus namespace, and your service identity credentials for the netTcpClient and the provider:   <!-- ACS credentials for the full trust consumer (Part2): -->   <netTcpClient identityName="fullTrustConsumer"                 symmetricKey="E3feJSMuyGGXksJi2g2bRY5/Bpd2ll5Eb+1FgQrXIqo="/> Then rebuild the solution and verify the unit tests work. If they’re green, your service is listening through Azure. Check out the client by navigating to http://localhost:53835/Sixeyed.Ipasbr.NetTcpClient. Enter a string and hit Go! - your string will be reversed by your on-premise service, routed through Azure: Using shared secret client credentials in this way means ACS is the identity provider for your service, and the claim which allows Send access to Service Bus is consumed by Service Bus. None of the authentication details make it through to your service, so your service is not aware who the consumer is (MSDN calls this "anonymous authentication").

    Read the article

  • What should be the minimal design/scope documentation before development begins?

    - by Oliver Hyde
    I am a junior developer working on my own in the programming aspect of projects. I am given a png file with 5-6 of the pages designed, most times in specific detail. From this I'm asked to develop the back end system needed to maintain the website, usually a cataloging system with products, tags and categories and match the front end to the design. I find myself in a pickle because when I make decisions based on assumptions about the flow of the website, due to a lack of outlining details, I get corrected and am required to rewrite the code to suit what was actually desired. This process happens multiple times throughout a project, often times on the same detail, until it's finally finished, with broken windows all through it. I understand that projects have scope creep, and can appreciate that I need to plan for this, but I feel that in this situation, I'm not receiving enough outlining details to effectively plan for the project, resulting in broken code and a stressed mind. What should be the minimal design/scope documentation I receive before I begin development?

    Read the article

  • Single IBAction for multiple UIButtons versus single IBAction for single UIButton

    - by Miraaj
    While using story-board there are two different approaches which my team mates follow: Approach 1: To bind unique action with each button, ie: Done button - binded to - doneButtonAction Cancel button - binded to - cancelButtonAction OR Approach 2: To bind single action to multiple buttons, ie: Done button - binded to - commonButtonAction Cancel button - binded to - commonButtonAction Then in commonButtonAction they prefer to use switch case like this: - (IBAction)commonButtonAction:(id)sender { UIButton *button = (UIButton *)sender; switch (button.tag) { case 201: // done button [self doneButtonAction:sender]; break; case 202: // cancel button [self cancelButtonAction:sender]; break; default: break; } } - (void)cancelButtonAction:(id)sender { // no interesting stuff, simple dismiss of view :-( } - (void)doneButtonAction:(id)sender { // some interesting stuff ;-) } Reasoning which they give to follow approach 2 is - in each view controller during code walk through anyone can easily identify where to find code related to button actions. While others discard this idea because they say that adding an extra switch case is unnecessary and is not a common practice. What are your views?

    Read the article

  • Most efficient way to rebuild a tree structure from data

    - by Ahsan
    Have a question on recursively populating JsTree using the .NET wrapper available via NuGet. Any help would be greatly appreciated. the .NET class JsTree3Node has a property named Children which holds a list of JsTree3Nodes, and the pre-existing table which contains the node structure looks like this NodeId ParentNodeId Data AbsolutePath 1 NULL News /News 2 1 Financial /News/Financial 3 2 StockMarket /News/Financial/StockMarket I have a EF data context from the the database, so my code currently looks like this. var parentNode = new JsTree3Node(Guid.NewGuid().ToString()); foreach(var nodeItem in context.Nodes) { parentNode.Children.Add(nodeItem.Data); // What is the most efficient logic to do this recursively? } as the inline comment says in the above code, what would be the most efficient way to load the JStree data on to the parentNode object. I can change the existing node table to suite the logic so feel free to suggest any changes to improve performance.

    Read the article

  • Playing a Song causing WP7 to crash on phone, but not on emulator

    - by Michael Zehnich
    Hi there, I am trying to implement a song into a game that begins playing and continually loops on Windows Phone 7 via XNA 4.0. On the emulator, this works fine, however when deployed to a phone, it simply gives a black screen before going back to the home screen. Here is the rogue code in question, and commenting this code out makes the app run fine on the phone: // in the constructor fields private Song song; // in the LoadContent() method song = Content.Load<Song>("song"); // in the Update() method if (MediaPlayer.GameHasControl && MediaPlayer.State != MediaState.Playing) { MediaPlayer.Play(song); } The song file itself is a 2:53 long, 2.28mb .wma file at 106kbps bitrate. Again this works perfectly on emulator but does not run at all on phone. Thanks for any help you can provide!

    Read the article

  • Few specific questions on how games are developed

    - by russ
    When it comes to programming games from the old school sega games like sonic to indie games or angry birds or even to more advance games like Diablo, how exactly is level design done? As in, are the levels sometimes designed straight out of code in an IDE? Or do they create a visual level design editor where things can be placed at the click of a mouse button? I'm imagining old school games or very simple ones like indies are done via code, where extremely complicated ones require a visual editor. Is this correct? Also, when it comes to libraries like SDL or XNA, how often are these used rather than just utilizing OpenGL or DirectX? What about creating your own game engine vs utilizing one already made? Do most use already built engines? This question is directed toward the whole gaming spectrum of indie/big game development. Thanks.

    Read the article

  • SQLAuthority News – Great Time Spent at Great Indian Developers Summit 2014

    - by Pinal Dave
    The Great Indian Developer Conference (GIDS) is one of the most popular annual event held in Bangalore. This year GIDS is scheduled on April 22, 25. I will be presented total four sessions at this event and each session is very different from each other. Here are the details of four of my sessions, which I presented there. Pluralsight Shades This event was a great event and I had fantastic fun presenting a technology over here. I was indeed very excited that along with me, I had many of my friends presenting at the event as well. I want to thank all of you to attend my session and having standing room every single time. I have already sent resources in my newsletter. You can sign up for the newsletter over here. Indexing is an Art I was amazed with the crowd present in the sessions at GIDS. There was a great interest in the subject of SQL Server and Performance Tuning. Audience at GIDS I believe event like such provides a great platform to meet and share knowledge. Pinal at Pluralsight Booth Here are the abstract of the sessions which I had presented. They were recorded so at some point in time they will be available, but if you want the content of all the courses immediately, I suggest you check out my video courses on the same subject on Pluralsight. Indexes, the Unsung Hero Relevant Pluralsight Course Slow Running Queries are the most common problem that developers face while working with SQL Server. While it is easy to blame SQL Server for unsatisfactory performance, the issue often persists with the way queries have been written, and how Indexes has been set up. The session will focus on the ways of identifying problems that slow down SQL Server, and Indexing tricks to fix them. Developers will walk out with scripts and knowledge that can be applied to their servers, immediately post the session. Indexes are the most crucial objects of the database. They are the first stop for any DBA and Developer when it is about performance tuning. There is a good side as well evil side to indexes. To master the art of performance tuning one has to understand the fundamentals of indexes and the best practices associated with the same. We will cover various aspects of Indexing such as Duplicate Index, Redundant Index, Missing Index as well as best practices around Indexes. SQL Server Performance Troubleshooting: Ancient Problems and Modern Solutions Relevant Pluralsight Course Many believe Performance Tuning and Troubleshooting is an art which has been lost in time. However, truth is that art has evolved with time and there are more tools and techniques to overcome ancient troublesome scenarios. There are three major resources that when bottlenecked creates performance problems: CPU, IO, and Memory. In this session we will focus on High CPU scenarios detection and their resolutions. If time permits we will cover other performance related tips and tricks. At the end of this session, attendees will have a clear idea as well as action items regarding what to do when facing any of the above resource intensive scenarios. Developers will walk out with scripts and knowledge that can be applied to their servers, immediately post the session. To master the art of performance tuning one has to understand the fundamentals of performance, tuning and the best practices associated with the same. We will discuss about performance tuning in this session with the help of Demos. Pinal Dave at GIDS MySQL Performance Tuning – Unexplored Territory Relevant Pluralsight Course Performance is one of the most essential aspects of any application. Everyone wants their server to perform optimally and at the best efficiency. However, not many people talk about MySQL and Performance Tuning as it is an extremely unexplored territory. In this session, we will talk about how we can tune MySQL Performance. We will also try and cover other performance related tips and tricks. At the end of this session, attendees will not only have a clear idea, but also carry home action items regarding what to do when facing any of the above resource intensive scenarios. Developers will walk out with scripts and knowledge that can be applied to their servers, immediately post the session. To master the art of performance tuning one has to understand the fundamentals of performance, tuning and the best practices associated with the same. You will also witness some impressive performance tuning demos in this session. Hidden Secrets and Gems of SQL Server We Bet You Never Knew Relevant Pluralsight Course SQL Trio Session! It really amazes us every time when someone says SQL Server is an easy tool to handle and work with. Microsoft has done an amazing work in making working with complex relational database a breeze for developers and administrators alike. Though it looks like child’s play for some, the realities are far away from this notion. The basics and fundamentals though are simple and uniform across databases, the behavior and understanding the nuts and bolts of SQL Server is something we need to master over a period of time. With a collective experience of more than 30+ years amongst the speakers on databases, we will try to take a unique tour of various aspects of SQL Server and bring to you life lessons learnt from working with SQL Server. We will share some of the trade secrets of performance, configuration, new features, tuning, behaviors, T-SQL practices, common pitfalls, productivity tips on tools and more. This is a highly demo filled session for practical use if you are a SQL Server developer or an Administrator. The speakers will be able to stump you and give you answers on almost everything inside the Relational database called SQL Server. I personally attended the session of Vinod Kumar, Balmukund Lakhani, Abhishek Kumar and my favorite Govind Kanshi. Summary If you have missed this event here are two action items 1) Sign up for Resource Newsletter 2) Watch my video courses on Pluralsight Reference: Pinal Dave (http://blog.sqlauthority.com)Filed under: MySQL, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, SQLAuthority Author Visit, SQLAuthority News, T SQL Tagged: GIDS

    Read the article

  • Obtaining In game Warcraft III data to program standalone AI

    - by Slav
    I am implementing common purpose behavioral algorithm and would like to test it under my lovely Warcraft III game and watch how it will fight against real players. The problem is how to obtain information about in game state (units, structures, environment, etc. ). Algorithm needs access to hard drive and possibly distributed computing, that's why JASS (WC3 Editor language) usage doesn't solve the issue. Direct 3D hooking is an approach, but it wasn't done for WC3 yet and significant drawback is inability to watch online at how AI performs since it uses the viewport to issue commands. How in game data can be obtained to a different process in a fastest and easiest way? Thank you.

    Read the article

< Previous Page | 787 788 789 790 791 792 793 794 795 796 797 798  | Next Page >