void AssociatedObject_SourceInitialized(object sender, EventArgs e)
{
AddHwndHook();
currentDpiRatio = MonitorDpi.GetScaleRatioForWindow(AssociatedObject);
UpdateDpiScaling(currentDpiRatio);
}
static PerMonitorDpiBehavior()
{
if (MonitorDpi.IsHighDpiMethodSupported())
{
// NB: We need to call this early before we start doing any
// fiddling with window coordinates / geometry
SafeNativeMethods.SetProcessDpiAwareness(PROCESS_DPI_AWARENESS.PROCESS_PER_MONITOR_DPI_AWARE);
}
}
IntPtr HwndHook(IntPtr hWnd, int message, IntPtr wParam, IntPtr lParam, ref bool handled)
{
switch (message)
{
case NativeConstants.WM_DPICHANGED:
var rect = (RECT)Marshal.PtrToStructure(lParam, typeof(RECT));
SafeNativeMethods.SetWindowPos(hWnd, IntPtr.Zero,
rect.left, rect.top, rect.right - rect.left, rect.bottom - rect.top,
SetWindowPosFlags.DoNotChangeOwnerZOrder | SetWindowPosFlags.DoNotActivate | SetWindowPosFlags.IgnoreZOrder);
var newDpiRatio = MonitorDpi.GetScaleRatioForWindow(AssociatedObject);
if (newDpiRatio != currentDpiRatio)
{
UpdateDpiScaling(newDpiRatio);
}
break;
}
return(IntPtr.Zero);
}
