windows-8 – 如何取消HttpClient GET Web请求

是否可以在 Windows 8中取消HttpClient GET Web请求.我正在寻找一种解决方案来取消我的Web请求,如果用户按下页面上的键.在我的应用程序中,我使用静态类来创建Web请求.

Alos我在应用程序中使用MVVM Light和静态视图模型.

在目前的情况下,即使用户按下后退按钮,
vm保持活动状态,回叫到达并在VM中执行.

所以我正在寻找一个解决方案来取消背面的请求.

试试这个

protected async override void OnNavigatedTo(NavigationEventArgs e)
{
    await HttpGetRequest();
}

public CancellationTokenSource cts = new CancellationTokenSource();
private async Task HttpGetRequest()
{
    try
    {
        DateTime Now = DateTime.Now;
        var httpClient = new HttpClient();
        var message = new HttpRequestMessage(HttpMethod.Get,"https://itunes.apple.com/us/RSS/toppaidapplications/limit=400/genre=6000/json");
        var response = await httpClient.SendAsync(message,cts.Token);
        System.Diagnostics.Debug.WriteLine("HTTP Get request completed. Time taken : " + (DateTime.Now - Now).TotalSeconds + " seconds.");
    }
    catch (TaskCanceledException)
    {
        System.Diagnostics.Debug.WriteLine("HTTP Get request canceled.");
    }
}

private void btnCancel_Click(object sender,RoutedEventArgs e)
{
    cts.Cancel();
}