Question

string url = "http://any_urls";
    MediaPlayer player = new MediaPlayer();

    public MainPage()
    {
        InitializeComponent();

        Debug.WriteLine("Download started");
        var file = Download().Result; // <-- Here's where it stucks
        Debug.WriteLine("Download finished");

        player.Source = MediaSource.CreateFromStorageFile(file);
        player.Play();
    }

    private async Task<StorageFile> Download()
    {
        StorageFile destinationFile = await ApplicationData.Current.LocalFolder.CreateFileAsync(
            "data.mp3", CreationCollisionOption.GenerateUniqueName);
        BackgroundDownloader downloader = new BackgroundDownloader();
        DownloadOperation download = downloader.CreateDownload(new Uri(url), destinationFile);
        await download.StartAsync();
        return destinationFile;
    }

我已经在PC和手机上进行了测试，他们都冻结了整个过程。任何人都可以解决这个问题，或者对此有什么好的替代方案吗？

Answer 1

忘了打电话＆＃34; AsTask＆＃34;开始下载的方法。

无法使用异步协同工具。

public MainPage()
{
    this.InitializeComponent();
}

private async void Page_Loaded(object sender, RoutedEventArgs e)
{
    Debug.WriteLine("Download started");
    var file = await DownloadAsync();
    Debug.WriteLine("Download finished");

    player.Source = MediaSource.CreateFromStorageFile(file);
    player.Play();
}

private async Task<StorageFile> DownloadAsync()
{
    StorageFile destinationFile = await ApplicationData.Current.LocalFolder.CreateFileAsync(
        "data.mp3", CreationCollisionOption.GenerateUniqueName);
    BackgroundDownloader downloader = new BackgroundDownloader();
    DownloadOperation download = downloader.CreateDownload(new Uri(url), destinationFile);
    await download.StartAsync().AsTask();
    return destinationFile;
}

UWP BackgroundDownloader即使在PC上也会冻结

1 个答案: