internal static extern int SetWindowCompositionAttribute(IntPtr hwnd, ref WINCOMPATTRDATA data);
public static extern int SetWindowCompositionAttribute(IntPtr hwnd, ref WINCOMPATTRDATA data);
private void SetBlurEffect() { Background = new SolidColorBrush(Color.FromArgb(0x90, 0xFF, 0xFF, 0xFF)); WindowStyle = WindowStyle.None; var interopHelper = new WindowInteropHelper(this); var accentPolicy = new ACCENTPOLICY { nAccentState = 3 }; var accentPolicySize = Marshal.SizeOf(accentPolicy); var accentPolicyPtr = Marshal.AllocHGlobal(accentPolicySize); Marshal.StructureToPtr(accentPolicy, accentPolicyPtr, false); var winCompatData = new WINCOMPATTRDATA { nAttribute = 19, ulDataSize = accentPolicySize, pData = accentPolicyPtr }; NativeMethods.SetWindowCompositionAttribute(interopHelper.Handle, ref winCompatData); Marshal.FreeHGlobal(accentPolicyPtr); }