public StrongHWNDSubclass(StrongHWND strongHwnd)
: base(new HWND(strongHwnd.DangerousGetHandle()))
{
// Note that we passed a new "weak" HWND handle to the base class.
// This is because we don't want the StrongHWNDSubclass processing
// a partially disposed handle in its own Dispose methods.
_strongHwnd = strongHwnd;
}
/// <summary>
/// Creates the hosted child window.
/// </summary>
/// <remarks>
/// Derived types override the BuildWindowCore virtual method to
/// create the child window. The child window is parented to
/// a seperate top-level window for the purposes of redirection.
/// The SafeWindowHandle type controls the lifetime of the
/// child window. It will be disposed when the RedirectedHwndHost
/// is disposed, or when the SafeWindowHandle is finalized. Set
/// the SafeWindowHandle.DestroyWindowOnRelease property to true
/// if you want the window destroyed automatically.
/// </remarks>
protected virtual HWND BuildWindowCore(HWND hwndParent)
{
StrongHWND hwndChild = StrongHWND.CreateWindowEx(
0,
"STATIC",
"Default RedirectedHwndHost Window",
WS.CHILD | WS.CLIPSIBLINGS | WS.CLIPCHILDREN,
0,
0,
0,
0,
hwndParent,
IntPtr.Zero,
IntPtr.Zero,
IntPtr.Zero);
return(hwndChild);
}
protected virtual void Dispose(bool disposing)
{
if (disposing)
{
StrongHWND strongHwnd = _hwnd as StrongHWND;
if (strongHwnd != null)
{
// Replace the StrongHWND reference with a regular "weak"
// HWND reference so that messages processed during
// disposing do not have to deal with a partially disposed
// SafeHandle.
_hwnd = new HWND(strongHwnd.DangerousGetHandle());
strongHwnd.Dispose();
// All done, replace the "weak" HWND reference with null.
_hwnd = null;
}
}
}
public TWindow CreateWindow(WindowParameters windowParams)
{
GCHandle gcHandle = new GCHandle();
IntPtr lpCreateParam = IntPtr.Zero;
if (windowParams.Tag != null)
{
gcHandle = GCHandle.Alloc(windowParams.Tag);
lpCreateParam = GCHandle.ToIntPtr(gcHandle);
}
StrongHWND hwnd = StrongHWND.CreateWindowEx(
windowParams.ExtendedStyle,
Name,
windowParams.Name,
windowParams.Style,
windowParams.WindowRect.X,
windowParams.WindowRect.Y,
windowParams.WindowRect.Width,
windowParams.WindowRect.Height,
windowParams.Parent,
IntPtr.Zero,
Marshal.GetHINSTANCE(typeof(TWindow).Module),
lpCreateParam);
TWindow createdWindow = null;
if (!hwnd.IsInvalid)
{
Debug.Assert(_createdWindow != null);
_createdWindow.TransferHandleOwnership(hwnd);
createdWindow = _createdWindow;
}
_createdWindow = null;
return(createdWindow);
}
internal void TransferHandleOwnership(StrongHWND hwnd)
{
Debug.Assert(hwnd == _hwnd); // equivalency, not reference equals
_hwnd = hwnd;
}
