/// <summary>
/// Retrieve the DPI value for the supplied window handle
/// </summary>
/// <param name="hWnd">IntPtr</param>
/// <returns>dpi value</returns>
public static uint GetDpi(IntPtr hWnd)
{
if (!User32Api.IsWindow(hWnd))
{
return(DpiHandler.DefaultScreenDpi);
}
// Use the easiest method, but this only works for Windows 10
if (WindowsVersion.IsWindows10OrLater)
{
return(GetDpiForWindow(hWnd));
}
// Use the second easiest method, but this only works for Windows 8.1 or later
if (WindowsVersion.IsWindows81OrLater)
{
var hMonitor = User32Api.MonitorFromWindow(hWnd, MonitorFrom.DefaultToNearest);
// ReSharper disable once UnusedVariable
if (GetDpiForMonitor(hMonitor, MonitorDpiType.EffectiveDpi, out var dpiX, out var dpiY))
{
return(dpiX);
}
}
// Fallback to the global DPI settings
using (var hdc = SafeWindowDcHandle.FromWindow(hWnd))
{
if (hdc == null)
{
return(DpiHandler.DefaultScreenDpi);
}
return((uint)Gdi32Api.GetDeviceCaps(hdc, DeviceCaps.LOGPIXELSX));
}
}
/// <summary>
/// Create a SafeDeviceContextHandle from a hWnd
/// </summary>
/// <param name="hWnd">IntPtr for hWnd</param>
/// <returns>SafeDeviceContextHandle</returns>
public static SafeDeviceContextHandle FromHWnd(IntPtr hWnd)
{
if (!User32Api.IsWindow(hWnd))
{
return(null);
}
var graphics = Graphics.FromHwnd(hWnd);
if (graphics == null)
{
return(null);
}
return(FromGraphics(graphics));
}
/// <summary>
/// Tests if the interopWindow still exists
/// </summary>
/// <param name="interopWindow">IInteropWindow</param>
/// <returns>True if it's still there.
/// Because window handles are recycled the handle could point to a different window!
/// </returns>
public static bool Exists(this IInteropWindow interopWindow)
{
return(User32Api.IsWindow(interopWindow.Handle));
}
