使用HttpClient的进度信息

Posted 2021-04-10

我想在Windows Phone 8.1 Silverlight中使用“Windows.Web.Http.HttpClient”实现进度条。

编辑：第一次尝试：

private async Task CheckProgress()
{
    var df = httpClient.GetAsync(new Uri(uriString, UriKind.Absolute)).Progress = Progress;

    // here i want to stop the execution till whole content downloaded

    // Reason to wait here
    // this client download will be used by one more async method. so i need to wait here till the file completely downloaded.

    // this whole is done in this method only ( requirement)
} 

private void  Progress(IAsyncOperationWithProgress<HttpResponseMessage, HttpProgress> asyncInfo, HttpProgress progressInfo)
{
   // here i getting the progress value.
   // i have already set a call back method that report the progress on the UI.
}

还有一次尝试：但获得例外Invocation of delegate at wrong time.

private async Task CheckProgress()
{
    var df = httpClient.GetAsync(new Uri(uriString, UriKind.Absolute))

    df.Progress =  Progress;

    await df;
    // here i want to stop the execution till whole content downloaded
} 

题：

所有，我想要停止CheckProgress()方法等待整个下载完成。

答案

我得到了我的问题的解决方案，但在我的Second Attempt只是有点想念。

private async Task CheckProgress()
{
    var df = httpClient.GetAsync(new Uri(uriString, UriKind.Absolute))

    df.Progress = (res, progress) =>
    { 
       // no separate event handler.
    }

    await df;   
} 

它工作正常。希望它会帮助别人欢呼:)