dotnet 读 WPF 源代码笔记 为什么设置了SplashScreen会让Application.Current.Activated事件不触发

  <ItemGroup>
    <SplashScreen Include="SplashScreen.png" />
  </ItemGroup>

    public partial class App : Application
    {
        public App()
        {
            Current.Activated += Current_Activated;
        }

        private void Current_Activated(object sender, EventArgs e)
        {
        }
    }

        [System.STAThreadAttribute()]
        [System.Diagnostics.DebuggerNonUserCodeAttribute()]
        [System.CodeDom.Compiler.GeneratedCodeAttribute("PresentationBuildTasks", "5.0.1.0")]
        public static void Main() 
        {
            SplashScreen splashScreen = new SplashScreen("SplashScreen.png");
            splashScreen.Show(true);
            App app = new App();
            app.InitializeComponent();
            app.Run();
        }

        private bool WmActivateApp(Int32 wParam)
        {
            int temp = wParam;
            bool isActivated = (temp == 0? false : true);

            // Event handler exception continuality: if exception occurs in Activate/Deactivate event handlers, our state would not
            // be corrupted because no internal state are affected by Activate/Deactivate. Please check Event handler exception continuality
            // if a state depending on those events is added.
            if (isActivated == true)
            {
                OnActivated(EventArgs.Empty);
            }
            else
            {
                OnDeactivated(EventArgs.Empty);
            }
            return false;
        }

        protected virtual void OnActivated(EventArgs e)
        {
            VerifyAccess();
            if (Activated != null)
            {
                Activated(this, e);
            }
        }

        private IntPtr AppFilterMessage(IntPtr hwnd, int msg, IntPtr wParam, IntPtr lParam, ref bool handled)
        {
            IntPtr retInt = IntPtr.Zero;
            switch ((WindowMessage)msg)
            {
                case WindowMessage.WM_ACTIVATEAPP:
                    handled = WmActivateApp(NativeMethods.IntPtrToInt32(wParam));
                    break;
                case WindowMessage.WM_QUERYENDSESSION :
                    handled = WmQueryEndSession(lParam, ref retInt);
                    break;
                default:
                    handled = false;
                    break;
            }
            return retInt;
        }

        private void EnsureHwndSource()
        {
            if (_parkingHwnd == null)
            {
                // _appFilterHook needs to be member variable otherwise
                // it is GC'ed and we don't get messages from HwndWrapper
                // (HwndWrapper keeps a WeakReference to the hook)

                _appFilterHook = new HwndWrapperHook(AppFilterMessage);
                HwndWrapperHook[] wrapperHooks = {_appFilterHook};

                _parkingHwnd = new HwndWrapper(
                                0,
                                0,
                                0,
                                0,
                                0,
                                0,
                                0,
                                "",
                                IntPtr.Zero,
                                wrapperHooks);
            }
        }