Question

I have a winform application (.NET 2.0 C#). From this application, I want to start another process (another winform application) and dock it to my window (or at least make it look like it is docked). So far, I can only find information about docking controls, not windows in separate processes. My first thought is to get the handle of the window and use unmanaged system calls to set the height/width and position of the window to my docking area. But before I got started, I wanted to check to see if any of you good people have done something similar. I have access to the source code of the application I want docked but would rather not make any changes if I can avoid it. I have complete programming control over what will be the parent application. Any advice? Thanks in advance!

Answer 1

The solution I have used before is to set the application window as a child of the control you want to dock it in.

using System.Diagnostics;
using System.Runtime.InteropServices;

private Process pDocked;
private IntPtr hWndOriginalParent;
private IntPtr hWndDocked;

[DllImport("user32.dll")]
public static extern IntPtr SetParent(IntPtr hWndChild, IntPtr hWndNewParent);

[DllImport("user32.dll", SetLastError = true)]
public static extern bool MoveWindow(IntPtr hWnd, int X, int Y, int nWidth, int nHeight, bool bRepaint);

private void dockIt()
{
    if (hWndDocked != IntPtr.Zero) //don't do anything if there's already a window docked.
        return;
    hWndParent = IntPtr.Zero;

    pDocked = Process.Start(@"notepad");
    while (hWndDocked == IntPtr.Zero)
    {
        pDocked.WaitForInputIdle(1000); //wait for the window to be ready for input;
        pDocked.Refresh();              //update process info
        if (pDocked.HasExited)
        {
            return; //abort if the process finished before we got a handle.
        }
        hWndDocked = pDocked.MainWindowHandle;  //cache the window handle
    }
    //Windows API call to change the parent of the target window.
    //It returns the hWnd of the window's parent prior to this call.
    hWndOriginalParent = SetParent(hWndDocked, Panel1.Handle);

    //Wire up the event to keep the window sized to match the control
    Panel1.SizeChanged += new EventHandler(Panel1_Resize);
    //Perform an initial call to set the size.
    Panel1_Resize(new Object(), new EventArgs());
}

private void undockIt()
{
    //Restores the application to it's original parent.
    SetParent(hWndDocked, hWndOriginalParent);
}

private void Panel1_Resize(object sender, EventArgs e)
{
    //Change the docked windows size to match its parent's size. 
    MoveWindow(hWndDocked, 0, 0, Panel1.Width, Panel1.Height, true);
}