You cannot use SendMessage (or PostMessage, the correct one) to simulate the state of the modifiers keys, like CTRL. You must use SendInput(). A keystroke like Ctrl+S is not untypically translated into a WM_COMMAND message. Use the Spy++ tool to see what happens when you type Ctrl+S by hand. If you see WM_COMMAND then you’re … Read more
What is LPCTSTR, and to what data type does it map in C#? LPCTSTR is a typedef for const TCHAR*. TCHAR is an attempt to abstract away the fact that the Windows API exists in both “ANSI” (char strings in a locale-specific encoding) and “Unicode” (UTF-16) versions. There is no actual PdhOpenQuery function; there is … Read more
Try this [DllImport(“kernel32.dll”, CharSet = CharSet.Auto, SetLastError = true)] private static extern IntPtr LoadLibrary(string libname); [DllImport(“kernel32.dll”, CharSet = CharSet.Auto)] private static extern bool FreeLibrary(IntPtr hModule); //Load IntPtr Handle = LoadLibrary(fileName); if (Handle == IntPtr.Zero) { int errorCode = Marshal.GetLastWin32Error(); throw new Exception(string.Format(“Failed to load library (ErrorCode: {0})”,errorCode)); } //Free if(Handle != IntPtr.Zero) FreeLibrary(Handle); If you … Read more
I was just going to edit this answer, but it doesn’t seem correct. So I’ll post my own… According to the Threads for C# page, which has a lot of synchronization tutorials, AutoResetEvent cannot be used for interprocess synchronization. However, a named EventWaitHandle can be used for interprocess synchronization. In the above page, visit the … Read more
PInvoke is certainly supported (that is how all of the code that interfaces with the OS works), but not in the specific case you listed. You cannot PInvoke to a win32 binary on Linux, unless you have somehow built a function-compatible version of it for Linux yourself. More realistically, you need to find a Linux … Read more
Google quickly found http://www.pinvoker.com (Wayback) (Compatiblity listed as VS2005, 2008, and 2010; it doesn’t seem to have been updated to work with newer versions) Microsoft’s C++/CLI compiler can also do this, if you use /clr:safe and #include the header file, it will generate p/invoke code which you can extract with e.g. ILSpy (free) or Red … Read more
Here is the solution I’ve used on many projects: name the 32-bit assembly with a “32-bit oriented name”. For example MyAssembly.Native.x86.dll name the 64-bit assembly with a “64-bit oriented name”. For example MyAssembly.Native.x64.dll compile the managed assembly as ‘Any Cpu’ ship everything in the same path Here is how I declare P/Invoke methods: [DllImport(“MyAssembly.Native.x86.dll”, EntryPoint … Read more
It’s not possible to pass a Nullable type into a PInvoke’d function without some … interesting byte manipulation in native code that is almost certainly not what you want. If you need the ability to pass a struct value as NULL to native code declare an overload of your PInvoke declaration which takes an IntPtr … Read more
Here is a working example. The hosting app is a simple WinForms application with a blank form (not included here), while the “guest app” has a main form (code behind included below) with some controls, including a test button to display a message after changing the guest form’s parent. The usual caveats linked to in … Read more
The usage of ref or out is not arbitrary. If the native code requires pass-by-reference (a pointer) then you must use those keywords if the parameter type is a value type. So that the jitter knows to generate a pointer to the value. And you must omit them if the parameter type is a reference … Read more