使用HwndSource在Win32应用程序中托管WPF UserControl

Question

I need to host my WPF UserControl in other window by Handle. I've tried to use HwndSource:

var userControl = new MyUserControl();
var parameters = new HwndSourceParameters();
parameters.WindowStyle = 0x10000000 | 0x40000000;
parameters.SetPosition(5, 5);
parameters.SetSize(300, 300);
parameters.ParentWindow = parentWindowHwnd;
var src = new HwndSource(parameters);
src.RootVisual = userControl;

But in this case arrows and tab keys don't work.

If I use ElementHost everything is OK:

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

var userControl = new UserControl1();
var elementHost = new ElementHost();
elementHost.Child = userControl;
elementHost.Left = 5;
elementHost.Top = 5;
elementHost.Width = 300;
elementHost.Height = 300;

SetParent(elementHost.Handle, parentWindowHwnd);

How can I get full functionality using HwndSource?

Answer 1

When you are using HwndSource you must register a handler for the windows messages.

this can done by call:

src.AddHook(this.messageHook);

The hook must check for wm_getdlgcode message.

    private IntPtr messageHook(IntPtr hwnd, int msg, IntPtr wparam, IntPtr lparam, ref bool handled)
    {
        switch (msg)
        {
            case WmGetDlgCode:
                {
                    handled = true;
                    return (IntPtr)(DlgcWantChars | DlgcWantTab | DlgcWantArrows | DlgcWantAllKeys);
                }
        }
        return IntPtr.Zero;
    }

return via Dlgc_WantChars, Dlgc_WantTab, Dlgc_WantArrows and Dlgc_WantAllKeys what you need.

check this for the message and codes: http://msdn.microsoft.com/en-us/library/windows/desktop/ms645425(v=vs.85).aspx

    private const int WmGetDlgCode = 0x0087;

    private const int DlgcWantChars = 0x0080;

    private const int DlgcWantTab = 0x0002;

    private const int DlgcWantAllKeys = 0x0004;

    private const int DlgcWantArrows = 0x0001;