'using System.Windows.Interop;' where is it? - window

Question

I saw this code for shadows around borderless windows but here i my problem. using System.Windows.Interop; is underlined and i cant find it in references. Also in public static void DropShadowToWindow(Window window) this Window is underlined so i guess its linked to Interop...
using System.Drawing.Printing;
using System.Runtime.InteropServices;
using System.Windows;
using System.Windows.Interop;
class DwmDropShadow
{
[DllImport("dwmapi.dll", PreserveSig = true)]
private static extern int DwmSetWindowAttribute(
IntPtr hwnd, int attr, ref int attrValue, int attrSize
);
[DllImport("dwmapi.dll")]
private static extern int DwmExtendFrameIntoClientArea(
IntPtr hWnd, ref Margins pMarInset
);
/// <summary>
/// Drops a standard shadow to a WPF Window, even a borderess window.
/// Only works with DWM (Vista and Seven).
///
/// This is much more efficient than setting AllowsTransparency to true
/// and using the DropShadow effect, as AllowsTransparency will turn off
/// acceleration for all the windows. (This is a huge performance issue.)
/// </summary>
/// <param name="window">Window to which the shadow will be applied</param>
public static void DropShadowToWindow(Window window)
{
if (!DropShadow(window))
{
window.SourceInitialized +=
new EventHandler(window_SourceInitialized);
}
}
private static void window_SourceInitialized(object sender, EventArgs e)
{
Window window = (Window)sender;
DropShadow(window);
window.SourceInitialized -= new EventHandler(window_SourceInitialized);
}
/// <summary>
/// The actual method that makes API calls to drop the shadow to the window
/// </summary>
/// <param name="window">Window to which the shadow will be applied</param>
/// <returns>True if the method succeeded, false if not</returns>
private static bool DropShadow(Window window)
{
try
{
WindowInteropHelper helper = new WindowInteropHelper(window);
int val = 2;
int ret1 = DwmSetWindowAttribute(helper.Handle, 2, ref val, 4);
if (ret1 == 0)
{
Margins m = new Margins {
Bottom = 0, Left = 0, Right = 0, Top = 0
};
int ret2 = DwmExtendFrameIntoClientArea(helper.Handle, ref m);
return ret2 == 0;
}
else
{
return false;
}
}
catch (Exception ex)
{
// Probably dwmapi.dll not found (incompatible OS)
return false;
}
}
}

Answer 1

It's in WindowsBase.DLL, which was introduced in .NET Framework 3.0. It is located in c:\Program Files\Reference Assemblies\Microsoft\Framework\v3.0\WindowsBase.dll

Answer 2

Just in case someone comes here to search for System.Windows.Interop.CompositionMode: it didn't make it to the final .Net 4.5 version.
See http://visualstudio.uservoice.com/forums/121579-visual-studio/suggestions/2644120-bring-back-the-hwndhost-isredirected-and-compositi?page=2&per_page=20