ContainerControl.ParentFormを使用してホストフォームへの参照を取得することはできましたが、プロダクション環境ではParentFormがnullを返して解決策を見つける必要があります。私はNewWndProcハンドラをtry/catchに入れました。例外を投げた場合に備えて、何か(もし何か)が投げられるかどうかわかりません。 Win32関数を使用し、Form.FocusedおよびForm.Activate().NETメソッドを使用しないでください。とにかく、コードは次のとおりです:
public class FocusFormWrapper
{
#region DllImport
public const int GWL_WNDPROC = (-4);
public const UInt32 WM_CLOSE = 0x0010;
public const UInt32 WM_PARENTNOTIFY = 0x0210;
public delegate IntPtr WndProcDelegate(IntPtr hWnd, uint msg, IntPtr wParam, IntPtr lParam);
[DllImport("user32.dll")]
[return: MarshalAs(UnmanagedType.Bool)]
public static extern bool IsWindow(IntPtr hWnd);
[DllImport("user32.dll", SetLastError = true)]
public static extern IntPtr GetWindowLong(IntPtr hWnd, int nIndex);
[DllImport("user32.dll", SetLastError = true)]
public static extern int SetWindowLong(IntPtr hWnd, int nIndex, IntPtr newWndProc);
[DllImport("user32.dll", SetLastError = true)]
public static extern IntPtr CallWindowProc(IntPtr lpPrevWndFunc, IntPtr hWnd, uint Msg, IntPtr wParam, IntPtr lParam);
[DllImport("user32.dll", SetLastError = true)]
private static extern IntPtr FindWindow(string _ClassName, string _WindowName);
[DllImport("user32.dll", SetLastError = true)]
public static extern int SendMessage(IntPtr hWnd, uint Msg, int wParam, int lParam);
[DllImport("user32.dll", SetLastError = true)]
private static extern bool SetForegroundWindow(IntPtr hWnd);
#endregion DllImport
private Form myForm = null;
private IntPtr hWndTarget = IntPtr.Zero;
private IntPtr oldWndProc = IntPtr.Zero;
private WndProcDelegate newWndProc;
private FocusFormWrapper()
{
}
public FocusFormWrapper(Form sourceForm)
{
if (sourceForm == null)
throw new ArgumentNullException("sourceForm");
if (!IsWindow(sourceForm.Handle))
throw new ArgumentException("sourceForm IsWindow failed");
myForm = sourceForm;
hWndTarget = myForm.Handle;
AddSubclass();
}
~FocusFormWrapper()
{
RemoveSubclass();
myForm = null;
newWndProc = null;
}
private int AddSubclass()
{
int result = -1;
if (myForm != null && newWndProc == null)
{
newWndProc = new WndProcDelegate(NewWndProc);
oldWndProc = GetWindowLong(hWndTarget, GWL_WNDPROC);
result = SetWindowLong(hWndTarget, GWL_WNDPROC, Marshal.GetFunctionPointerForDelegate(newWndProc));
}
return result;
}
public int RemoveSubclass()
{
int result = -1;
if (myForm != null && newWndProc != null)
{
result = SetWindowLong(hWndTarget, GWL_WNDPROC, oldWndProc);
newWndProc = null;
}
return result;
}
public IntPtr NewWndProc(IntPtr hWnd, uint msg, IntPtr wParam, IntPtr lParam)
{
try
{
if (msg == WM_PARENTNOTIFY && !myForm.Focused)
{
// Make this form auto-grab the focus when menu/controls are clicked
myForm.Activate();
}
if (msg == WM_CLOSE)
{
RemoveSubclass();
}
}
catch
{
}
return CallWindowProc(oldWndProc, hWnd, msg, wParam, lParam);
}
}