private static async Task <Tuple <ExtendedSplashScreenContent, TaskCompletionSource <object> > > CreateExtendedSplashScreenContentAsync(Window hostWindow, AppStartInfo info)
{
// 创建创建扩展启动屏幕方法为 null。
if (info.ExtendedSplashScreen == null)
{
return(Tuple.Create <ExtendedSplashScreenContent, TaskCompletionSource <object> >(null, null));
}
ExtendedSplashScreenContent extendedSplashScreenContent = null;
TaskCompletionSource <object> extendedSplashScreenTcs = null;
await hostWindow.Dispatcher.RunAsync(CoreDispatcherPriority.Normal, () =>
{
extendedSplashScreenContent = info.ExtendedSplashScreen();
if (extendedSplashScreenContent != null)
{
extendedSplashScreenTcs = new TaskCompletionSource <object>();
EventHandler extendedSplashScreenFinishedHandler = null;
extendedSplashScreenFinishedHandler = delegate
{
extendedSplashScreenContent.Finished -= extendedSplashScreenFinishedHandler;
extendedSplashScreenTcs.SetResult(null);
};
extendedSplashScreenContent.Finished += extendedSplashScreenFinishedHandler;
}
});
return(Tuple.Create <ExtendedSplashScreenContent, TaskCompletionSource <object> >(extendedSplashScreenContent, extendedSplashScreenTcs));
}
private static async Task ShowExtendedSplashScreenAsync(Window hostWindow, bool isNewWindow, IActivatedEventArgs args, AppStartInfo info)
{
// 窗口中是否已经有内容。
if (await GetIsWindowExistContentAsync(hostWindow))
{
return;
}
var temp = await CreateExtendedSplashScreenContentAsync(hostWindow, info);
// 扩展屏幕内容。
ExtendedSplashScreenContent extendedSplashScreenContent = temp.Item1;
// 扩展启动屏幕结束回调信号。
TaskCompletionSource <object> extendedSplashScreenTcs = temp.Item2;
// 窗口内容。
UIElement hostWindowContent = null;
if (extendedSplashScreenContent != null)
{
// 如果扩展屏幕窗口内容不为 null，则创建扩展启动屏幕容器并赋值到 hostWindowContent 变量。
hostWindowContent = await BuildExtendedSplashScreenAsync(hostWindow, extendedSplashScreenContent, args);
}
if (hostWindowContent == null && isNewWindow)
{
// 对于新窗口，必须确保存在内容。
await hostWindowContent.Dispatcher.RunAsync(CoreDispatcherPriority.Normal, () =>
{
hostWindowContent = new ContentControl();
});
}
await ShowWindowContentAsync(hostWindow, hostWindowContent);
if (isNewWindow)
{
// 切换到新窗口。
await SwitchToWindowAsync(hostWindow);
}
// 使用了扩展启动屏幕。
if (extendedSplashScreenTcs != null)
{
// 等待回调信号。
await extendedSplashScreenTcs.Task;
}
// 清除窗口内容，准备导航操作。
await hostWindow.Dispatcher.RunAsync(CoreDispatcherPriority.Normal, () =>
{
SetContent(hostWindow, null);
});
}
private static async Task <UIElement> BuildExtendedSplashScreenAsync(Window hostWindow, ExtendedSplashScreenContent extendedSplashScreenContent, IActivatedEventArgs args)
{
// 用于等待 ExtendedSplashScreen 构造完成。因为 RunAsync 方法第二个参数签名是 async void，不是 async Task。
TaskCompletionSource <UIElement> containerTcs = new TaskCompletionSource <UIElement>();
await hostWindow.Dispatcher.RunAsync(CoreDispatcherPriority.Normal, async() =>
{
ExtendedSplashScreen extendedSplashScreen = await ExtendedSplashScreen.CreateAsync(args.SplashScreen, extendedSplashScreenContent);
containerTcs.SetResult(extendedSplashScreen);
});
return(await containerTcs.Task);
}
