/// <summary>
/// Once the classname and style bits have been set, this can be called to register the class.
/// </summary>
private unsafe void RegisterClass()
{
NativeMethods.WNDCLASS windowClass = new NativeMethods.WNDCLASS();
string localClassName = _className;
if (localClassName == null)
{
// If we don't use a hollow brush here, Windows will "pre paint" us with COLOR_WINDOW which
// creates a little bit if flicker. This happens even though we are overriding wm_erasebackgnd.
// Make this hollow to avoid all flicker.
windowClass.hbrBackground = Gdi32.GetStockObject(Gdi32.StockObject.HOLLOW_BRUSH);
windowClass.style = _classStyle;
_defaultWindProc = DefaultWindowProc;
localClassName = "Window." + Convert.ToString((int)_classStyle, 16);
}
else
{
// A system defined Window class was specified, get its info
if (!UnsafeNativeMethods.GetClassInfoW(NativeMethods.NullHandleRef, _className, ref windowClass))
{
throw new Win32Exception(Marshal.GetLastWin32Error(), SR.InvalidWndClsName);
}
localClassName = _className;
_defaultWindProc = windowClass.lpfnWndProc;
}
_windowClassName = GetFullClassName(localClassName);
_windProc = new User32.WNDPROC(Callback);
windowClass.lpfnWndProc = Marshal.GetFunctionPointerForDelegate(_windProc);
windowClass.hInstance = Kernel32.GetModuleHandleW(null);
fixed(char *c = _windowClassName)
{
windowClass.lpszClassName = c;
if (UnsafeNativeMethods.RegisterClassW(ref windowClass) == 0)
{
_windProc = null;
throw new Win32Exception();
}
}
}