为什么我的WebClient上传文件代码挂起？

我正在使用VSTS 2008 + C＃+。Net 3.5 + ASP.Net + IIS 7.0在客户端开发Windows窗体应用程序以上载文件，在服务器端我使用aspx文件接收此文件。

我发现单击按钮触发上传事件后，我的客户端应用程序将挂起。 任何想法有什么不对，怎么解决？ 谢谢！

客户端代码，

public partial class Form1 : Form { private static WebClient client = new WebClient(); private static ManualResetEvent uploadLock = new ManualResetEvent(false); private static void Upload() { try { Uri uri = new Uri("https://localhost/Default2.aspx"); String filename = @"C:Test1.dat"; client.Headers.Add("UserAgent", "TestAgent"); client.UploadProgressChanged += new UploadProgressChangedEventHandler(UploadProgressCallback); client.UploadFileCompleted += new UploadFileCompletedEventHandler(UploadFileCompleteCallback); client.UploadFileAsync(uri, "POST", filename); uploadLock.WaitOne(); } catch (Exception e) { Console.WriteLine(e.StackTrace.ToString()); } } public static void UploadFileCompleteCallback(object sender, UploadFileCompletedEventArgs e) { Console.WriteLine("Completed! "); uploadLock.Set(); } private static void UploadProgressCallback(object sender, UploadProgressChangedEventArgs e) { Console.WriteLine("{0} uploaded {1} of {2} bytes. {3} % complete...", (string)e.UserState, e.BytesSent, e.TotalBytesToSend, e.ProgressPercentage); // Console.WriteLine (e.ProgressPercentage); } public Form1() { InitializeComponent(); } private void button1_Click(object sender, EventArgs e) { Upload(); } } 

服务器端代码：

  protected void Page_Load(object sender, EventArgs e) { string agent = HttpContext.Current.Request.Headers["UserAgent"]; using (FileStream file = new FileStream(@"C:TestAgent.txt", FileMode.Append, FileAccess.Write)) { byte[] buf = Encoding.UTF8.GetBytes(agent); file.Write(buf, 0, buf.Length); } foreach (string f in Request.Files.AllKeys) { HttpPostedFile file = Request.Files[f]; file.SaveAs("C:\Test\UploadFile.dat"); } } 

 public partial class Form1 : Form { private static WebClient client = new WebClient(); private static ManualResetEvent uploadLock = new ManualResetEvent(false); private void Upload() { try { Cursor=Cursors.Wait; Uri uri = new Uri("https://localhost/Default2.aspx"); String filename = @"C:Test1.dat"; client.Headers.Add("UserAgent", "TestAgent"); client.UploadProgressChanged += new UploadProgressChangedEventHandler(UploadProgressCallback); client.UploadFileCompleted += new UploadFileCompletedEventHandler(UploadFileCompleteCallback); client.UploadFileAsync(uri, "POST", filename); } catch (Exception e) { Console.WriteLine(e.StackTrace.ToString()); this.Cursor=Cursors.Default; this.Enabled=false; } } public void UploadFileCompleteCallback(object sender, UploadFileCompletedEventArgs e) { // this callback will be invoked by the async upload handler on a ThreadPool thread, so we cannot touch anything GUI-related. For this we have to switch to the GUI thread using control.BeginInvoke if(this.InvokeRequired) { // so this is called in the main GUI thread this.BeginInvoke(new UploadFileCompletedEventHandler(UploadFileCompleteCallback); // beginInvoke frees up the threadpool thread faster. Invoke would wait for completion of the callback before returning. } else { Cursor=Cursors.Default; this.enabled=true; MessageBox.Show(this,"Upload done","Done"); } public Form1() { InitializeComponent(); } private void button1_Click(object sender, EventArgs e) { Upload(); } } }