當設置了owner的子窗口顯示後，點擊子窗口外部，需要一種反饋機制（反饋動畫）。

實現：

1.觸發源

每次點擊子窗口外部，即母窗口時，事件捕捉如下

HwndSource hwndSource = PresentationSource.FromVisual(this.Owner) as HwndSource;//窗口過程

hwndSource?.AddHook(WndProc);

也可以調用WindowInteropHelper，獲取母窗口句柄。

var hwnd = new WindowInteropHelper(this.Owner).Handle;
if (hwnd != IntPtr.Zero)
{
　　var hwndSource = HwndSource.FromHwnd(hwnd);
　　hwndSource?.AddHook(WndProc);
}

事件中，啟動動畫

 private static IntPtr WndProc(IntPtr hwnd, int msg, IntPtr wParam, IntPtr lParam, ref bool handled)
    {
         if (msg != 0x20) return IntPtr.Zero;
         if (lParam.ToInt32() == 0x201fffe) _storyboard?.Begin();
         return IntPtr.Zero;
    }

2.動畫設置

窗口抖動 動畫

            var
 
 scaleXDoubleAnimation = new DoubleAnimationUsingKeyFrames();
            var scaleYDoubleAnimation = new DoubleAnimationUsingKeyFrames();

            scaleXDoubleAnimation.KeyFrames.Add(new EasingDoubleKeyFrame{KeyTime = KeyTime.FromTimeSpan(TimeSpan.FromMilliseconds(0)),Value = 1.0});
            scaleXDoubleAnimation.KeyFrames.Add(
 
new EasingDoubleKeyFrame{KeyTime = KeyTime.FromTimeSpan(TimeSpan.FromMilliseconds(100)),Value = 0.95});
            scaleXDoubleAnimation.KeyFrames.Add(new EasingDoubleKeyFrame{KeyTime = KeyTime.FromTimeSpan(TimeSpan.FromMilliseconds(200)),Value = 1.0});

            scaleYDoubleAnimation.KeyFrames.Add(new EasingDoubleKeyFrame{KeyTime = KeyTime.FromTimeSpan(TimeSpan.FromMilliseconds(0)),Value = 1.0});
            scaleYDoubleAnimation.KeyFrames.Add(new EasingDoubleKeyFrame{KeyTime = KeyTime.FromTimeSpan(TimeSpan.FromMilliseconds(100)),Value = 0.95});
            scaleYDoubleAnimation.KeyFrames.Add(new EasingDoubleKeyFrame{KeyTime = KeyTime.FromTimeSpan(TimeSpan.FromMilliseconds(200)),Value = 1.0});

            Storyboard.SetTarget(scaleXDoubleAnimation, window);
            Storyboard.SetTarget(scaleYDoubleAnimation, window);
            Storyboard.SetTargetProperty(scaleXDoubleAnimation, new PropertyPath("(UIElement.RenderTransform).(ScaleTransform.ScaleX)"));
            Storyboard.SetTargetProperty(scaleYDoubleAnimation, new PropertyPath("(UIElement.RenderTransform).(ScaleTransform.ScaleY)"));

            _storyboard = new Storyboard{Children =new TimelineCollection { scaleXDoubleAnimation, scaleYDoubleAnimation }};

設置後，點擊窗口外部，子窗口喚醒時，會有窗口大小變化（抖動的效果）

窗口陰影 動畫

            var animation = new DoubleAnimationUsingKeyFrames();

            animation.KeyFrames.Add(new EasingDoubleKeyFrame{KeyTime = KeyTime.FromTimeSpan(TimeSpan.FromMilliseconds(0)),Value = 0});
            animation.KeyFrames.Add(new EasingDoubleKeyFrame{KeyTime = KeyTime.FromTimeSpan(TimeSpan.FromMilliseconds(200)),Value = 50});
            animation.KeyFrames.Add(new EasingDoubleKeyFrame{KeyTime = KeyTime.FromTimeSpan(TimeSpan.FromMilliseconds(400)),Value = 0});
            
            Storyboard.SetTarget(animation, window);
            Storyboard.SetTargetProperty(animation, new PropertyPath("(FrameworkElement.Effect).(DropShadowEffect.BlurRadius)"));

            _storyboard = new Storyboard
            {
                Children = new TimelineCollection { animation }
            };

設置後，點擊窗口外部，子窗口喚醒時，會有窗口外部陰影變化

關鍵字：模態窗口，窗口抖動，窗口陰影

WPF window 子窗口反饋效果（抖動/陰影漸變)