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

53,352

Solution 1

Not sure it works, but you can try that :

IntPtr handle = Process.GetCurrentProcess().MainWindowHandle;

Solution 2

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;
};

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.

Solution 3

Try this:

[DllImport("user32.dll", EntryPoint = "FindWindow", SetLastError = true)]
public static extern IntPtr FindWindowByCaption(IntPtr zeroOnly, string lpWindowName);
…

Console.Title = "Test";
…

IntPtr handle = FindWindowByCaption(IntPtr.Zero, Console.Title);

Solution 4

I've just solved this problem for myself (unfortunately before seeing Thomas's answer which is much quicker). Well, here's another way for those who are not satisfied with his answer. I'm writing this answer because I want to provide another answer + a better way to design the Program class if you're treating your console as a Window. Let's begin with that design:

I've kind of changed the default style of the Program class. I've actually made it into a class that has a program in it, and not just one method which represent it and uses other classes for content. (If you don't know what I mean, not important).

The reason I had to do it is because I wanted to write the following event handler:

private void CatchUnhandled(Object sender, UnhandledExceptionEventArgs e)
{
    var exception = e.ExceptionObject as Exception;
    MessageBox.Show(this, exception.Message, "Error"); // Check out 1st arg.
}

It overloads this method MessageBox.Show(IWin32Window, String, String).

Because Console doesn't implement IWin32Window, I had to implement it myself, of course, in order to just call this in the 1st argument.

Here is the implementation of it and everything else:

Note: this code is copy-pasted from my application, you can feel free to change the access modifiers

Program Class Declaration:

internal class Program : IWin32Window
{
    ...
}

IWin32Window Implementation:

public IntPtr Handle
{
    get { return NativeMethods.GetConsoleWindow(); }
}

It uses the following class:

internal static class NativeMethods
{
    [DllImport("kernel32.dll")]
    internal static extern IntPtr GetConsoleWindow();
}

Now, the problem is that you can't actually call this in Main, being a static method, so whatever was in Main I've moved to a new method named Start and all Main is doing is creating a new Program and calling Start.

private static void Main()
{
    new Program().Start();
}

private void Start()
{
    AppDomain.CurrentDomain.UnhandledException += CatchUnhandled;

    throw new Exception();
}

The result was, of course, a message-box with my console's window as an owner.
Using this method for a message-box, is of course only one application of this method.

Solution 5

I don't think there is such a thing. The console window is not accessible to the application. You MIGHT try to iterate the process list looking for your own process name. The Process class IIRC contains a property for the program's main window handle, which might be the console window for console applications - which I'm not sure of.

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Grant
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Grant

Updated on July 09, 2022

Comments

  • Grant
    Grant over 1 year

    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.

  • Thomas Levesque
    Thomas Levesque over 14 years
    "iterate the process list looking for your own process name" => not a very efficient approach... you could find it by the PID, or use } ;)
  • Thorsten Dittmar
    Thorsten Dittmar over 14 years
    Whoops - Thomas Levesque's answer is even more elegant. While relying on the same property, he doesn't need to iterate. I forgot that you can access to current process directly...
  • Thorsten Dittmar
    Thorsten Dittmar over 14 years
    @Thomas: Sorry, didn't see your comment before. Of course, iterating is far more inefficient. I didn't remember the GetCurrentProcess() method...
  • Piers Karsenbarg
    Piers Karsenbarg over 12 years
    For anyone else looking 2-22 years later; yes, this did work (for me).
  • John Gardner
    John Gardner over 12 years
    this appears to only work if your process started the console. if you run it from another console, you always get zero. it looks like you need to use findwindowbycaption in other situations (see support.microsoft.com/kb/124103)
  • Carl Walsh
    Carl Walsh over 10 years
    This worked for me when debugging in Visual Studio, but when I ran without debugging it didn't. Double clocking the myProgram.exe in bin/Release did work, but FindWindowByCaption might be the more robust solution.
  • tetrahydrocannon
    tetrahydrocannon over 10 years
    In short the answer is: [DllImport("kernel32.dll")] internal static extern IntPtr GetConsoleWindow();
  • Bitterblue
    Bitterblue over 10 years
    Earlier I always had much respect for this window and I never though I could manipulate it via code but it is a simple window that is not much different than others. The line above works and you can also enumerate and find it via WinApi and do all kinds of crazy stuff to it. Just be careful it has a WndProc that makes it resize a little differently.
  • James Johnston
    James Johnston over 8 years
    This should be the accepted answer. GetConsoleWindow is the right way to do this; many of the other answers here are just plain goofy.
  • WiredEarp
    WiredEarp over 7 years
    This is the correct answer IMHO, unless you want to spend time figuring out why your application doesn't work when you run it from the console as opposed to the IDE. Thanks Ivan.