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  - 1
    - PInvoke conversion works fine but with Win32 error How are you getting the Win32 error code By default the marshaler assumes that the Win32 error code isn't used so it might or might not return the correct value. Add SetLastError=true to your DllImport attribute to tell the marshaller to retrieve the error code. Then use Marshal.GetGetLastWin32Error to retrieve the message. Note that it appears to be your code that you're calling so it might be easier to set up mixed mode debugging and step into your unmanaged code in the debugger to confirm that the data is coming across OK. Your P/Invoke signature looks OK but you didn't post the callback signature so I can't confirm that. Michael Taylor - 10/4/07 http://p3net.mvps.org Tag: Visual C# General Show Desktop Visual C#
  - 2
    - Using MSIEXEC Hi here are two ways to find it: I. Using the YouProductSetup.vdproj 1. Open in a text editor (ex: notepade ) your setup project file (ex: YourProjectSetup.vdproj ) 2. In the section " Deployable ", Subsection " Product ", the key " ProductCode " will give you the product code. For me: "ProductCode" = "8:{8C3CB5AD-C67B-4539-940E-1234567890AF}" so my product code is: 8C3CB5AD-C67B-4539-940E-1234567890AF II Using regedit 1. Install your product " YourProductSetup.msi " 2. Open regedit (Windows->run->regedit). 3. go in My Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurentVersion\Installer\UserData 4. Find you product (ex: Edit -> find -> "YourProduct" ) 5. You should find it at several places, including in a key called InstallProperties . 6. In this key there will be key called UninstallString , this string contains the key. Ex, for me: UninstallString = "MsiExec.exe /I{8C3CB5AD-C67B-4539-940E-1234567890AF}" And my product code is 8C3CB5AD-C67B-4539-940E-1234567890AF. Note: A professional installer (ex: wise) will allow you to do it (more) easily. Regards, Tag: Visual C# General Show Desktop Visual C#
  - 3
    - May I use FieldAccessException for own purpose ? Yes, it would be bad style. The intended use is "...thrown when there is an invalid attempt to access a private or protected field inside a class" and the manual states "This exception is typically thrown when the access level of a field in a class library is changed, and one or more assemblies referencing the library have not been recompiled." If you use it for your own purposes, it is going to become very confusing to someone who needs to use your class and receives this exception. It is easy to create your own exception type by inheriting from System.ApplicationException, and this will elliminate any confusion. public class FieldAlreadyInitializedException: ApplicationException { } ... if (fieldIsInitialized) throw new FieldAlreadyInitializedException(); Tag: Visual C# General Show Desktop Visual C#
  - 4
    - Running a C# Application Outside Windows Operating Systems - Is there a way? I don't see any relation with Xenocode products and your problem. Applicatio writen in C# will use .NET Framework, which means you can use it, after windows is loaded. For your problem you need to use some low level program language like C, C++. There are convertors of .NET application to be able to run it on Linux or Unix, like Grasshopper from www.mainsoft.com , but i don't see any use of that too. Tag: Visual C# General Show Desktop Visual C#
  - 5
    - RTF to PDF convertion using C# Hi, You can use Acrobat.dll. Acrobat. AcroAVDocClass _acroDoc = new Acrobat. AcroAVDocClass (); Acrobat. AcroPDDoc _pdDoc = null ; _acroDoc.Open(strNonPDFFile, strPDFFile); _pdDoc = (Acrobat. AcroPDDoc )(_acroDoc.GetPDDoc()); _pdDoc.Save(Acrobat. PDSaveFlags .PDSaveFull, strPDFFile); _pdDoc.Close(); _pdDoc = null ; _acroDoc.Close(1); _acroDoc = null ; Tag: Visual C# General Show Desktop Visual C#
  - 6
    - confused in populating array! Anonymousaah, If you want to do what I think you want to do, this should work. Note that you will have to validate the textbox to insure that there are no unauthorized characters, and converting from scientific notion is its own problem. But if you just have a simple textbox and a button, this should fill up two arrays. The basic strategy here is that we already have a lot of good information about the condition of the data. We have a newline delimiter and a comma delimiter. So we split the data first, by newline and shove that into an array of strings. Then we split the data a second time into a smaller chunk, and convert that chunk into the double neeeded for insertion into the double array. There are more elegant solutions, but this will work. Best if luck, Ryan /// Declare the data arrays Double [] Array1 = new double [4]; Double [] Array2 = new double [4]; //declare the holding string array. We will need it //in a couple of lines to strip commas out of the string [] sHoldingString = new string [1]; //Take the information and slap it into an array of strings //as indicated by newline string [] sMyStringArray = txtArrayIn.Text.Split( '\n' ); //Now that we have the array of strings, walk through the //array of strings, split out the individual strings, and slap it into an array for ( int i = 0; i < 4; i++) { //Take out the line sHoldingString = sMyStringArray .Split( ',' ); //now we have the data. Convert to a couble and assign Array1 = Convert .ToDouble(sHoldingString[0]); Array2 = Convert .ToDouble(sHoldingString[1]); } Tag: Visual C# General Show Desktop Visual C#
  - 7
    - Passing a string from a C++ DLL GetString accepts an already-allocated array, right If so, then it should just take a char*, not a char**. And then you don't need to pass outStr as a ref (because the method isn't setting outStr itself to point to some address, it is only setting the contents of the array). __declspec(dllexport) void __stdcall GetString(char* outStr, int* outStrLen) ... extern static void GetString(char[] outStr, ref int outStrLen) ... Treat this as just a guess, but probably somewhat better than a random guess. Tag: Visual C# General Show Desktop Visual C#
  - 8
    - Programming the parallel port help!!! Check out this article, Parallel Port Interfacing in C#.NET Programming Since the parrallel port for the most part has been replaced by USB...the impetus for .Net examples as you have found are fleeting. Tag: Visual C# General Show Desktop Visual C#
  - 9
    - how to call contructor of base class from constructor of inherit class You must call it from declaration of the constructor of your derived class: public class ChildClass : baseclass { public ChildClass( int paramSomething) : base (paramSomething) { // more stuff... } //or public ChildClass() : base( 1 ) { // more stuff ... } } Tag: Visual C# General Show Desktop Visual C#
  - 10
    - Equals Method Is Vector3 a class or a struct Tag: Visual C# General Show Desktop Visual C#
  - 11
    - How can I recover a lost vshost.exe.manifest file I've never heard of anyone having problems rebuilding an app because the manifest file is missing. Are you building a C++ app In general the manifest file is auto-generated in that case. The VSHost binary is used for VS debugging so it is definitely not needed for deployment but the <app>.exe.manifest might be unless it is embedded in the app. Michael Taylor - 6/20/07 http://p3net.mvps.org Tag: Visual C# General Show Desktop Visual C#
  - 12
    - PropertyGrid Cloning objects I have the same problem, only that instead of using clone the propertygrid creates the copy using serialization, as described here: http://forums.microsoft.com/MSDN/ShowPost.aspx PostID=1208317&SiteID=1 Did anyone find a solution to this Tag: Visual C# General Show Desktop Visual C#
  - 13
    - Type Reference and Object Name I'll take a whack at this discussion. Let's start simpler though: MyClass var; In the above code the MyClass is a type and var is a variable of type MyClass . The variable itself is stored on the stack when invoked from a method (our assumption during this conversation) and inside a class when used as a field. It's value is currently undefined so if you were to look on the stack we would see a value of 0 or perhaps garbage (depends on the language). Now let's give the variable a value. new MyClass(); We have now allocated an instance of MyClass in memory somewhere (only the CLR knows where). In this specific case we call the base constructor to initialize it. Creation of reference types can be assumed to involve two steps (although we see them as only one). The first step is to allocate memory somewhere for them. The second step is to initialize them. The CLR allocates the memory for us. The constructor(s) we define do the initialization. Upon the completion of the above statement we now have an instance of MyClass floating in memory somewhere. We generally what to do something with new instances so we need to store the address where the instance resides somewhere: var = new MyClass(); The above statement creates an instance of MyClass , initializes it and then stores the address (in memory) of the instance in the variable var (which itself is stored on the stack). So if we now look on the stack we should see that var has a value (assume 0x12345678) and if we were to go into memory at the given address we should see our instance of the class. We can now say that we have an instance of MyClass stored in a variable but we more likely say that var is an instance of MyClass . Now let's take a step further. MyClass var = new MyClass(); We combine the creation of the local variable with the creation of the instance of the class into a single line. The above code is equivalent to (and cleaner than) this: MyClass var; var = new MyClass(); Still the effect is the same. We can change what var points to by assignment or creating new instances: MyClass var2 = new MyClass(); var = var2; In the above code we create a new instance of MyClass and store it in another local variable var2 . We then assign the new instance to our original var variable. The instance that var originally pointed to is still floating around in memory but since we no longer have any variables with its address it will eventually get cleaned up by the garbage collector. Meanwhile var and var2 both point to the same place in memory. If we happen to change a field of the class through one of the variables then we'll also see the change through the other variable. This is because MyClass is a reference type. If it were a value type then the rules are different. Now to add in the differing types: IMyClass var = new MyClass(); On the right side of the assignment the same thing happens as earlier. On the left we create a local variable. However we specify that its type is IMyClass rather than MyClass . It is important to understand that a variable has a type and the instance that it points to might be a different type. Provided the types are compatible (i.e. the instance can be converted to the variable's type) then it is legal. This is useful because oftentimes you want your variables to work with as many different types as possible. Therefore variables are often typed to be the most generic type available that still allows you to call the members that you want. So with the above code var is of type IMyClass and therefore any usage of that variable is limited to the members exposed by IMyClass . However the variable can point to (or be assigned a value from) any type that implements the IMyClass interface. We are separating ourselves from the actual implementation details of the class which is generally a good thing. Therefore, although var is of type IMyClass , it actually points to an instance of type MyClass . The compiler/runtime ensures that the members are called correctly. For this to work MyClass would have to have been defined similar to this: public class MyClass : IMyClass { } To finish up this works the same way if we were talking about base classes and derived classes. So if we had this definition: public class MyDerivedClass : MyBaseClass { } Then we could do this: MyBaseClass var = new MyDerivedClass(); However the next block of code will fail because we can not convert a base class to a derived class: MyDerivedClass var = new MyBaseClass(); Hope this clarifies things. I recommend that you get a good book on OOP because these concepts are consistent in all OOP languages. The only real .NET difference is reference vs. value types. Once you get a good understanding of OOP then look up reference vs. value types in MSDN and that should clarify the differences. Michael Taylor - 4/19/07 http://p3net.mvps.org Tag: Visual C# General Show Desktop Visual C#
  - 14
    - is my code leaking memory? you can easily allocate too much new memory through all those operations without 'leaking' any memory, try a forced GC.Collect() with GC. WaitForPendingFinalizers () from time to time so that GC.Collect() can catch up with your memory allocation. Tag: Visual C# General Show Desktop Visual C#
  - 15
    - XmlReader and deep copy Unfortunately, I don't think it's possible. XmlReader is abstract and is not attributed as Serializable. The framework classes that implement XmlReader aren't public so you can't get at the state data. Tag: Visual C# General Show Desktop Visual C#
  - 16
    - Casting parent class to child You can't downcast if that is right term. If the parent object is created, it cannot be cast to the child...but here is a way to work around it... Create an interface which the parent implements. Have the child override functionality if needed or just expose the parents functionality. Change the cast to be an interface pointer and do the operations. Tag: Visual C# General Show Desktop Visual C#
- Next
  - 1
    - Using C++ SDK in C#? If that SDK exports C style functions, you can call them from C# using the PInvoke functionality as described here http://msdn2.microsoft.com/en-us/library/55d3thsc(VS.80).aspx If that SDK exports classes then you may need to write a C wrapper for those and call those wrapper methods using PInvoke. Tag: Visual C# General Show Desktop Visual C#
  - 2
    - Migration to 2005 No and no. Snippets didn't exist in VS2003 so there is no upgrade path. The snippet format is pretty easy to figure out and there is a code snippet editor available online so you can copy-paste the snippet blocks you want to create. The toolbox can't be migrated nor can any of the settings. However the toolbox allows you to add new controls easily by using a simple browser-style dialog where you can select the controls to add to a new or existing tab. Any third-party components you rely on should automatically add themselves to the toolbox. Your other settings you'll have to migrate by hand. Once you get everything configured the way you want be sure to export the settings to a new file so you can store it off and reuse it either on another machine or at the odd occasion where VS loses them. A great feature over prior versions. Michael Taylor - 10/21/07 http://p3net.mvps.org Tag: Visual C# General Show Desktop Visual C#
  - 3
    - storing values between two forms The value is blank because in webform2 you are creating a new instance of BaseClass, not referencing the instance in which you set the value of A in webform1. It sounds like you want to use a static property or session state . Tag: Visual C# General Show Desktop Visual C#
  - 4
    - Cannot Open Image file from Console Application (C#) We need some more information I'm afraid. How are you viewing the files What happens when you try to view the image file Can you show us the code and any errors that happens Tag: Visual C# General Show Desktop Visual C#
  - 5
    - report logging Is your report in a file, or in a database Tag: Visual C# General Show Desktop Visual C#
  - 6
    - Environment.SpecialFolder.MyDocuments in C#1.1 You'll have to PInvoke SHGetFolderPath with the CSIDL_PERSONAL value Something like: Code Snippet [ DllImport ( "shfolder.dll" , CharSet = CharSet . Auto )] internal static extern int SHGetFolderPath ( IntPtr hwndOwner, int nFolder, IntPtr hToken, int dwFlags, StringBuilder lpszPath); StringBuilder lpszPath = new StringBuilder ( 260 ); const int CSIDL_PERSONAL = 5; Win32Native . SHGetFolderPath ( IntPtr . Zero , CSIDL_PERSONAL, IntPtr . Zero , 0 , lpszPath ); string path = lpszPath . ToString (); Tag: Visual C# General Show Desktop Visual C#
  - 7
    - I would like to ask about Face Detection Ki Ki, Odds are that if you are planning on doing some sort of face detection, packages already exist which will be much more extensive than anything that you can write by yourself. Most of this is probably written in C++ for the speed aspect, but you can probably p/invoke to it. You also don��t really state what kind of face detection that you want to do. Are you planning on detecting a face in a picture, detecting a picture is a picture of a face, rather than a picture of some other kind of object, or detecting that a face is the face of a certain person If you are doing this as a school or personal project, I might try this: Take a picture of a face and convert it to a bitmap. Then search out in a spiral from the center of the picture, testing every couple of pixels until you see an area of extensive dark-light contrast. Odds are, this area is the eyeball. Search until you find the center of the dark spot. This will be the iris. Then search in straight lines out from this iris until you find the second iris. Measure the distance between the center of the two irises. The distance between the two irises will vary enough between people to give you a reasonable confidence that the picture is a face, and it is a certain person��s face. This will probably work for a college project, but if this is for an industrial, or governmental application, you should probably take a look at existing packages. Ryan Tag: Visual C# General Show Desktop Visual C#
  - 8
    - C# Newbie - Problem with syntax? The @ symbol just disables the escape codes in the following string. \t would be an escape code, but by putting the @ symbol in front of the string that escape code is disabled. From what I see your code should run fine... Are you sure the test.txt is not hidden or you have no rights to access the directory from your code I tried this one and it's working great here! bool exists = System.IO. File .Exists( @"C:\Users\Chris\Downloads\JoostSetup-0.8.1.exe" ); Tag: Visual C# General Show Desktop Visual C#
  - 9
    - myprocess.Start() is not working for me in .net 2003 Hi I have just tried to run in it on my VS.Net2003 and it worked. Of course using different name in FileName. So probably you should try running another program in your process (I used "calc.exe") to see if it will work. Can you run "myBatchFile.exe" from your console, or windows explorer does it run properly By reducing the problem to small step, I guess you will be able to uncover the reason of the problem. Regards Tag: Visual C# General Show Desktop Visual C#
  - 10
    - only view select text in textbox Try this: Code Snippet string line = "1234567890" ; this .textBox1.Text = line.Substring(0, 8); Tag: Visual C# General Show Desktop Visual C#
  - 11
    - Dialogs Cause Program to Freeze Hi, any multithreaded programming at all in your code Mark. Tag: Visual C# General Show Desktop Visual C#
  - 12
    - Problems with Intellisense popup behavior Hi Earl, There is no timing setting as to how long an intellisense should be up. Hitting ESC or typing a commit character will dismiss the list and commit the preselected item if any. To know what those commit characters are, go to Tools | options | text editor | C# | intellisense and there is an edit box with the default list of commit characters that you can then modify if you like. I have never heard anything like this. Do you have any thing else on your machine that is running at the time of VS and grabbing the focus Losing the focus will make the intellisense go away too. Does it happen every time you are using VS in every project Is it possible to attach a video of this issue Let me know, Thanks Suma Sushilendra [MSFT] Tag: Visual C# General Show Desktop Visual C#
  - 13
    - 2 simple questions Answer to Question 2: Code Snippet public static class RandomTxt { static Random r = new Random(); // Init using multiple source of noise, including the time at which it is executed. static public string Next() { StringBuilder b = new StringBuilder(); for (int i = 0; i < 5; ++i) { int n = r.Next(10 + 26); if (n < 10) b.Append(n); else b.Append((char)('A' + n - 10)); } return b.ToString(); } } Example of RandomTxt, and Short answer to Question 3: Code Snippet { // Example of RandomTxt: Console.WriteLine(RandomTxt.Next()); Console.WriteLine(RandomTxt.Next()); } { // // Example of MD5: byte[] data = ASCIIEncoding.Default.GetBytes("Hello World !"); System.Security.Cryptography.MD5 md5 = new System.Security.Cryptography.MD5CryptoServiceProvider(); byte[] result = md5.ComputeHash(data); foreach (byte b in result) Console.Write(b.ToString("x")); Console.WriteLine(); } Tag: Visual C# General Show Desktop Visual C#
  - 14
    - How to use string.replace to replace "\\" with "\" in a string? Hi, try: string s1 = "abc//123" .Replace( "//" , "/" ); string s2 = @"abc\\123" .Replace( @"\\" , @"\" ); Note, that if you look at s2 in the debugger you will still see \\ in the debugger window because it escapes the \, but it really only has one \, try printing it to the console to verify. Mark. Tag: Visual C# General Show Desktop Visual C#
  - 15
    - Visual Studio Set References Copy Local to True If the project file is in CM then VS can't change it. Is VS auto-checking out the project file whenever you open it I'm not aware of any issues with VS resetting the copy local flag. It could be a problem with your installation but I'm baffled as to what. I am concerned about why you would want to mix the two modes though. This is adding undo complexity to an already complex system with little gains. The general guidelines are to copy local for all assemblies except those in the GAC (but VS will handle that automatically anyway). Trying to share files in separate directories makes the development and production environments harder to manage IMO. It can also cause problems. For example if you reference assemblies A and B where B is not copied locally and A references B (with copy locally) then B will still get copied into the bin directory and used even though you don't have copy local set, I believe. Michael Taylor - 10/4/07 http://p3net.mvps.org Tag: Visual C# General Show Desktop Visual C#
  - 16
    - 2D Drawing Options Hi, have you looked into WPF, this is the new presentation framework. It is capable of 2D or 3D graphics and unlike GDI+ is capable of utilizing graphics hardware to perform the rendering. Mark. Tag: Visual C# General Show Desktop Visual C#

Paulo_Amaral

How can I bring the Desktop to the top, like pressing [Windows]+[D ]

Important: the way of minimizing all windows by calling ShowWindow (p.MainWindowHandle, SW_MINIMIZE) for each process p returned by Process.GetProcess() doesn't solve my problem, but something like to minimize all windows listed in systray would.

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Re: Visual C# General Show Desktop

Timo S

Open add a reference dialog and select Com tab. There you will find some kind of Microsoft Shell ******** dll. Import it into your program and create a new instance of Shell class or something. There you will find MinimizeAll() method.. I will give you more detailed instructions if you can't figure this out. I would give you now, but I'm not using my own computer right now.. .

Regards,
Timo Salomaki

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Re: Visual C# General Show Desktop

Paulo_Amaral

The reference is Microsoft Sheel Controls And Automation.

I did the following:

Shell32.ShellClass shell = new Shell32.ShellClass();
shell.MinimizeAll();

Thanks!

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