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• how to call a C++ dll from C# windows application project

  - by chathuradd

  I have created a dll in C++ using a Class Library project in Visual Studio. I need to call a method in the dll from a C# application. I got to know there are 2 approches. One is to add the dll project reference to C# project or use DllExport to export method. However when I tried in both ways it always gives the following error when the dll method is called in runtime. An unhandled exception of type 'System.BadImageFormatException' occurred in TestClient.exe Additional information: An attempt was made to load a program with an incorrect format. (Exception from HRESULT: 0x8007000B) Can i know how to avoid this problem ? Thanks in advance!

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• Preprocessor directive to test if this is C or C++

  - by Collin

  I'm trying to find a standard macro which will test whether a header file is being compiled as C or as C++. The purpose of this is that the header may be included by either C or C++ code, and must behave slightly differently depending on which. Specifically: In C, I need this to be the code: extern size_t insert (const char*); In C++, I need this to be the code: extern "C" size_t insert (const char*); Additionally, is there a way to avoid putting #ifdef's around every declaration in the header?

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• IntelliJ Split Window Navigation

  - by jmquigley

  If I split the editor window (horizontal or vertical) into N tab groups, how do I switch/toggle from one tab group to another via the keyboard? If all of the tabs are in the same group you can switch from each tab easily (CTRL + right/left arrow), but when they're in separate tab groups I can't. I've searched through the key mappings and have not found one that seems to accomplish this. I know I can use the mouse, but I'm trying to find ways to avoid the mouse and stay with the keyboard. TIA for any help on this.

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• website is very slow on IE

  - by Bhupi

  Hi, I need to know what can be the main reasons (apart from the basics like grouping CSS selectors, reducing image size, using image sprite etc.) which makes a website slow on Internet Explorer, because my website works fine on the others like FF, chrome etc. Is it the huge use of Javascript framework (ie. jQuery, extjs, prototype)? Is it because of the use of plugins based on JS framework? Should I use core javascript and remove the use of any js framework? Should I try to avoid using jQuery(document).ready()? in case of jQuery framework? Above some of the questions which I know and please answer the questions which I couldn't ask because of lesser knowledge about these. I need to make my website perform well on IE (6,7,8) also please suggest. Thanks

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• Enterprise Library Validation Block - Should validation be placed on class or interface?

  - by Robert MacLean

  I am not sure where the best place to put validation (using the Enterprise Library Validation Block) is? Should it be on the class or on the interface? Things that may effect it Validation rules would not be changed in classes which inherit from the interface. Validation rules would not be changed in classes which inherit from the class. Inheritance will occur from the class in most cases - I suspect some fringe cases to inherit from the interface (but I would try and avoid it). The interface main use is for DI which will be done with the Unity block.

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• Is shortening properties names worth it?

  - by raam86

  in how to node Blog rolling with node.js and mongoDB the author mentions it's a good idea to shorten proprieties names: ....oft-reported issue with mongoDB is the size of the data on the disk... each and every record stores all the field-names .... This means that it can often be more space-efficient to have properties such as 't', or 'b' rather than 'title' or 'body', however for fear of confusion I would avoid this unless truly required! I am aware of solutions of how to do it I am more intrested in when is it truly required?

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• How to assess the risk of a java version upgrade?

  - by Roy Tang

  I'm being asked to assess whether we can safely upgrade the java version on one of our production-deployed webapps. The codebase is fairly large and we want to avoid having to regression test everything (no automated tests sadly), but we've already encountered at least one problem during some manual testing (XmlStringReader.getLocalName now throws an IllegalStateExeption when it just used to return null) and higher-ups are pretty nervous about the upgrade. The current suggested approach is to do a source compare of the JDK sources for each version and assess those changes to see which ones might have impact, but it seems there's a lot of changes to go through (and as mentioned the codebase is kinda large). Is it safe and easier to just review the java version changes for each version? Or is there an easier way to conduct this assessment? Edit: I forgot to mention the version upgrade being considered is a minor version upgrade, i.e. 1.6.10 to 1.6.33

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• Is the "message" of an exception culturally independent?

  - by Ray Hayes

  In an application I'm developing, I have the need to handle a socket-timeout differently from a general socket exception. The problem is that many different issues result in a SocketException and I need to know what the cause was. There is no inner exception reported, so the only information I have to work with is the message: "A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond" This question has a general and specific part: is it acceptable to write conditional logic based upon the textual representation of an exception? Is there a way to avoid needing exception handling? Example code below... try { IPEndPoint endPoint = null; client.Client.ReceiveTimeout = 1000; bytes = client.Receive(ref endPoint); } catch( SocketException se ) { if ( se.Message.Contains("did not properly respond after a period of time") ) { // Handle timeout differently.. } }

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• Is there a way to cause a new C++ class instance to fail, if certain conditions in the contructor ar

  - by Jim Fell

  As I understand it, when a new class is instantiated in C++, a pointer to the new class is returned, or NULL, if there is insufficient memory. I am writing a class that initializes a linked list in the constructor. If there is an error while initializing the list, I would like the class instantiator to return NULL. For example: MyClass * pRags = new MyClass; If the linked list in the MyClass constructor fails to initialize properly, I would like pRags to equal NULL. I know that I can use flags and additional checks to do this, but I would like to avoid that, if possible. Does anyone know of a way to do this? Thanks.

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• How to enforce lazy loading of entities on certain conditions

  - by Samuel

  We have an JPA @Entity class (say User) which has a @ManyToOne reference (say Address) loaded using the EAGER option which in turn loads it's own @ManyToOne fields (say Country) in a EAGER fashion. We use the EntityQuery interface to count the list of User's based on a search criteria, during such a load all the @ManyToOne fields which have been marked as EAGER get loaded. But in order to perform a EntityQuery.resultCount(), I actually don't need to load the @ManyToOne fields. Is there a way to prevent loading of the EAGER fields in such cases so that we can avoid the unnecessary joins?

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• Multivalue parametres in SSRS- display in the report

  - by pfeffer

  I just started working with SSRS, so this question might seem silly. Anyway, for now I'm trying to avoid multi-valued parameters, because I want my parameters to be able to be NULL. So I'm just passing a comma-separated string of ID values to my stored procedure, and everything works. The problem I encountered is that I want to display the actual values, not IDs, in the report, so that users can see, what filter was used. If that were a multi-valued parameter, I would simply use JOIN function, but now I am out of ideas and would really appreciate some help. Thanks!

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• mysql reference result from subquery

  - by iamrohitbanga

  this is what i am doing update t1 set x=a,y=b where a and b are obtained from (select query here) i know the select query the select query returns multiple results which are the same when i use group by or distinct query execution slows down considerably a and b are forward references so mysql reports an error i want to set a equal to the value obtained in the first row and b equal to the value obtained in the first row for the respective columns, to avoid group by. i don't know how to refer to the first result from the select query. how can i achieve all this?

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• C# - Why can't I enforce derived classes to have parameterless constructors?

  - by FrisbeeBen

  I am trying to do the following: public class foo<T> where T : bar, new { _t = new T(); private T _t; } public abstract class bar { public abstract void someMethod(); // Some implementation } public class baz : bar { public overide someMethod(){//Implementation} } And I am attempting to use it as follows: foo<baz> fooObject = new foo<baz>(); And I get an error explaining that 'T' must be a non-abstract type with a public parameterless constructor in order to use it as parameter 'T' in the generic type or method. I fully understand why this must be, and also understand that I could pass a pre-initialized object of type 'T' in as a constructor argument to avoid having to 'new' it, but is there any way around this? any way to enforce classes that derive from 'bar' to supply parameterless constructors?

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• Java: Reflection against casting when you know superclass

  - by Ema

  I don't know exactly how to define my doubt so please be patient if the question has already been asked. Let's say I have to dinamically instantiate an object. This object will surely be instance of a subclass of a known, immutable class A. I can obtain dinamically the specific implementation class. Would it be better to use reflection exactly as if I didn't know anything about the target class, or would it be preferrable/possible to do something like: A obj = (Class.forName("com.package.Sub-A")) new A(); where Sub-A extends A ? The purpose would be to avoid reflection overhead times... Thank you in advance.

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• Raphael how to get last path and last circle, if i have 2 elements in the paper?

  - by 3gwebtrain

  I need to find the last path or circle in a paper, in order to perform further calculations to draw more elements, and calling 'paper.bottom' only gets the last element. Is there any way to get shapes of specific types, e.g. bottom.path, bottom.circle or traverse for the n'th child? I want to avoid using jQuery selectors, as i can't retrieve any properties from those. An example of a paper populated with shapes: var paper = Raphael('paper',500,500); var c1 = paper.circle(100,100,50) var p1 = paper.path("M10 20l70 0") var c2 = paper.circle(200,100,50)

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• What programming languages do you consider indispensable in your experience?

  - by Federico Ramponi

  Each programming language comes with its concepts, best practices, libraries, tools, community, in one word: culture. Learning more than one programming language will make you a better programmer, for the more concepts you learn, the faster you will feel comfortable when the next language or technology will come. Mine, so far, are C, some C++, and Python, and many times I read that it would be worth learning LISP, for "the profound enlightenment experience you will have when you finally get it" (quoting Eric Raymond). My questions are: Which is the next one you would consider a good investment to learn? Of the many programming languages you have learnt and worked with, which ones do you consider to be an essential part of one's CS culture, and why? EDIT. Further question: is there any language you would sincerely advise to avoid as a waste of time? (The famous, and questionable, slatings in this letter from Dijkstra come to my mind.)

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• JPA 2.0 Eclipse Link ... Composite primary keys

  - by Parhs

  I have two entities(actually more but it doenst matter) Exam and Exam_Normals Its a oneToMany relationship... The problem is that i need a primary key for Exams_Normals PK (Exam_ID Item) Item should be 1 2 3 4 5 etc.... But cant achieve it getting errors An alternative would be to: I cound use an IDENTITY and a ManyToOne relationship at Exam_Normals but that should be like PK(Exam_Normals_ID) and a reference to Exam and an extra collumn Item to keep an order.. SO 3 collumns But to avoid the alternative tried I tried with @IdClass and got errors Tried @EmbeddedID everything nothing works Any idea??

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• Online payment service recommendation?

  - by Shadowman

  We're currently in the process of looking for an online payment service that will allow us to accept credit cards, etc. However, our business model also involves revenue sharing in a model similar to that of iTunes. That is, content creators will be able to sell content through our site and we take a small percentage of the revenue. Can anyone recommend an online payment service that supports this model? We're also interested in: Accept all major credit cards Being able to do international transactions in the appropriate local currency Recurring transactions (monthly, yearly, etc.) Additionally, if the service provided a Java API for integration or the ability to broker PayPal transactions that would be an added bonus. I know Amazon provides a hosted payment service, but I'd prefer not to require all of our customers to have an Amazon account. That provides an additional barrier to entry that we'd prefer to avoid. I'd appreciate any recommendations you can provide!

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• jqGrid: Is it possible to commit a cell change when tabbing off instead of pressing Enter?

  - by The Matt

  I have a simple in-line edit in my grid, and I want to commit the change when the user tabs off the textbox. The default behavior of jqGrid forces the user to press 'Enter' to commit the change, but this is non-intuitive for our users. onSelectRow: function(id) { $(gridCoreGroups).editRow(id, true, undefined, function(response) { alert("hello world"); } } I've worked my way through the events provided, but they all happen as a result of the user pressing 'Enter', which I want to avoid. Is there something I can wire up that would trigger an action when the user tabs off this cell?

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• Can a function defined in a bookmarklet be called from a page-level script?

  - by Soviut

  I have a bookmarklet that needs to open a new window/tab. In order to avoid the popup blocker, I need to call the window.open() method directly in the bookmarklet ie: at the browser-level. However, I want to keep the bookmarklet updatable by loading external Javascript files. To do this, the bookmarklet needs to append script nodes to the DOM. If i were to put window.open() code in one of these externally loaded scripts, the popup blocker would block it since its page-level. What I want to know is if I can create a wrapper function around window.open() in my bookmarklet, then call it from the externally loaded script? What is the scope and what are the permissions on a wrap such as this?

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• Unreachable, existing variable

  - by Oden

  I'm new at as3, maybe thats the reason why i don't understand, why the setInterval causes an error. <mx:Script> <![CDATA[ import flash.utils.setInterval; import mx.controls.Alert; [Bindable] public var MyInt:int = 500; setInterval(function():void{ ++MyInt; },1000); ]]> </mx:Script> I have a label where the value of MyInt gets visible, the bind works perfect, i've tested it several ways, and i i create a button it grows the number, but if i use the setInterval function i get an error: Access of undefined property myInt. Why? What does cause this? Please explain it, so I can avoid errors like this. Thanks

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• Is there any way to store full size image returned from camera activity in internal memory ?

  - by SimpleGuy

  I am using Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE); intent.putExtra(MediaStore.EXTRA_OUTPUT,Uri.fromFile(externalFileObj)); intent to call default camera activity. To get full image you need to specify intent.putExtra(). But this always requires URI that works only for external storage files. I tried to create a temp.jpg image in internal memory and pass its URI Uri.fromFile(new File(getFilesDir() + "/temp.jpg")); but the camera activity won't return back after the image is captured. So there is no way to get Full size image from default camera application in our activity without using any external storage ? Assuming that the device do not have SD card or currently in use is there no way I can avoid using it ? Yes I know we can create our own camerapreview surface but I want to use the default camera application as it is natural with many more options. Thanks.

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• iPhone - How to use #define in Universal app

  - by Satyam svv

  I'm creating universal app that runs oniphone and ipad. I'm using #define to create CGRect. And I want to use two different #define - one for iPhone and one for iPad. How can I declare them so that correct one will be picked by universal app.......... I think I've to update little more description to avoid confusion. I've a WPConstants.h file where I'm declaring all the #define as below #define PUZZLE_TOPVIEW_RECT CGRectMake(0, 0, 480, 100) #define PUZZLE_MIDDLEVIEW_RECT CGRectMake(0, 100, 480, 100) #define PUZZLE_BOTTOMVIEW_RECT CGRectMake(0, 200, 480, 100) The above ones are for iphone. Similarly for iPad I want to have different #define How can I proceed further?

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• How to handle dependency files in a cross-platform manner?

  - by Brian Knoblauch

  I'm working on updating an old app. It has some dependency files that live in the same directory as the app. Obviously this broke when Windows Vista came out (since it violates the API and Vista/7 now enforce that (XP didn't)). Ideally, I'd like to avoid hardcoding anything into the app for just Windows. I can live with that if I have to though. I've already been down that path with pulling the APPDATA and LOCALAPPDATA environment variables, but that doesn't help any since they just give you the current user area... I need these to live somewhere accessible for all users, and I'd like to obey the Windows API expectations that they go into the all user appdata area. Suggestions?

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• c# .net framework subtracting time-span from date

  - by smkngspcmn

  I want to subtract a time-span from a date-time object. Date is 1983/5/1 13:0:0 (y/m/d-h:m:s) Time span is 2/4/28-2:51:0 (y/m/d-h:m:s) I can use the native DateTime and TimeSpan objects to do this, after converting years and months of the time-span to days (assuming a 30 day month and a ~364 day year). new DateTime(1981,5,1,13,0,0).Subtract(new TimeSpan(878,13,51,0)); With this i get the result: {12/4/1978 11:09:00 PM} But this is not exactly what i expected. If i do this manually (assuming a 30 day month) i get 1981/0/3-10:9:0 This is pretty close to what i'm after except i shouldn't get 0 for month and year should be 1980. So can someone please show me how i can do this manually and avoid getting a 0 month value? Also why do i get a completely different value when i use native classes?

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