How do I get the handle of a console application's window

Question

Can someone tell me how to get the handle of a Windows console application in C#? In a Windows Forms application, I would normally try this.Handle.

Answer 1

Not sure it works, but you can try that :

IntPtr handle = Process.GetCurrentProcess().MainWindowHandle; 

Answer 2

• The aforementioned Process.MainWindowHandle method only works for the process that started the console
• The FindWindowByCaption method is inherently unreliable

Here's a robust way to do this:

The related functions from the Console Win32 API are:

[DllImport("kernel32.dll", SetLastError = true)] static extern bool AttachConsole(uint dwProcessId); [DllImport("kernel32.dll")] static extern IntPtr GetConsoleWindow(); [DllImport("kernel32.dll", SetLastError=true, ExactSpelling=true)] static extern bool FreeConsole(); 

• For the console the current process is attached to, just GetConsoleWindow() is enough
• For the console another process is attached to, attach to it as well with AttachConsole, call GetConsoleWindow, them immediately detach with FreeConsole.

For the extra cautious, register a console event handler before attaching (and unregister it after detaching) as well so you don't accidentally get terminated if a console event happens in the tiny time frame you're attached to the console:

[DllImport("kernel32.dll")] static extern bool SetConsoleCtrlHandler(ConsoleCtrlDelegate HandlerRoutine,    bool Add); delegate Boolean ConsoleCtrlDelegate(CtrlTypes CtrlType); enum CtrlTypes : uint {     CTRL_C_EVENT = 0,     CTRL_BREAK_EVENT,     CTRL_CLOSE_EVENT,       CTRL_LOGOFF_EVENT = 5,     CTRL_SHUTDOWN_EVENT }  bool is_attached=false;     ConsoleCtrlDelegate ConsoleCtrlDelegateDetach = delegate(CtrlType) {      if (is_attached = !FreeConsole())          Trace.Error('FreeConsole on ' + CtrlType + ': ' + new Win32Exception());      return true; }; 

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Making changes to the current process just to read something is rather ugly (when this is a console process, this gets really ugly since it requires a helper process to avoid terminating the current console). Nevertheless, further investigation shows that there's no other way short of injecting into the csrss process or the target process.

Console correspondence information is located in and managed by csrss.exe (or a multitude of those, one for each session, since Vista), so it can't be retrieved with the likes of ReadProcessMemory. All that csrss exposes is the CSRSS LPC API. There's only one relevant function in the full API list, SrvGetConsoleWindow. And it doesn't accept a PID but determines that of the calling party as seen in an alternative implementation or the function's disassembly in winsrv.dll.