获取标签中的http文件大小,下载位置和URL

Question

我正在使用它来下载文件并获取%信息和完成的信息.我想知道如何获取正在下载的文件的大小以及URL远程地址和保存文件的本地地址.

private void Form1_Load_1(object sender, EventArgs e)
        {
     label21.Text = "Download in progress...";
            WebClient webClient = new WebClient();
     webClient.DownloadFileCompleted += new AsyncCompletedEventHandler(Completed);
     webClient.DownloadProgressChanged += new DownloadProgressChangedEventHandler(ProgressChanged);
     webClient.DownloadFileAsync(new Uri("http://www.somesite.com/Update/Updates.zip.010"), @"Updates.zip.010");
 }

private void ProgressChanged(object sender, DownloadProgressChangedEventArgs e)
        {
            progressBar1.Value = e.ProgressPercentage; //Progress Bar Handler
            label1.Visible = true;
            label1.Text = progressBar1.Value.ToString() + " %"; //Adds percent to a label
        }

private void Completed(object sender, AsyncCompletedEventArgs e)
        {
            label11.Visible = true;
            label11.Text = "Done";
        }

Answer 1

我只是重写了杰伊写给他自己的问题的评论,所以它会更容易阅读:

HttpWebRequest req = (HttpWebRequest)WebRequest.Create("http://cdn.sstatic.net/stackoverflow/img/favicon.ico");
req.Method = "HEAD";
// HttpWebRequest.GetResponse(): From MSDN: The actual instance returned
// is an HttpWebResponse, and can be typecast to that class to access 
// HTTP-specific properties. 
HttpWebResponse resp = (HttpWebResponse)req.GetResponse();
long len = resp.ContentLength;

刚刚意识到它正是如何从http标题中获取文件大小(也许这个问题应该标记为重复？).