silverlight文件上传下载实现方法(下载保（silverlight文件上传下载实现方法(下载保）

search了非常多的文章，总算勉强实现了。有许多不完善的地方。

在HCLoad.Web项目下新建目录Pics复制一张图片到根目录下。

图片名：Bubble.jpg 右击->属性->生成操作：Resource

UC_UpDown.xaml

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<UserControl x:Class="HCLoad.UC_UpDown" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Width="500" Height="500"> <StackPanel Background="White" Height="450"> <Button Content="down" Click="Button_Click"></Button> <HyperlinkButton Content="下载保存" NavigateUri="http://localhost:4528/download.ashx?fileName=aa.txt" TargetName="_self" x:Name="lBtnDown" /> <TextBlock x:Name="tbMsgString" Text="下载进度" TextAlignment="Center" Foreground="Green"></TextBlock> <Button x:Name="btnDownload" Content="DownLoad Pictures" Width="150" Height="35" Margin="15" Click="btnDownload_Click"/> <Border Background="Wheat" BorderThickness="5" Width="400" Height="280"> <Image x:Name="imgDownLoad" Width="400" Height="300" Margin="15" Stretch="Fill"/> </Border> <Button x:Name="btnUpLoad" Content="UpLoad Pictures" Width="150" Height="35" Margin="15" Click="btnUpLoad_Click"/> </StackPanel> </UserControl>

UC_UpDown.xaml.cs

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using System; using System.Collections.Generic; using System.Linq; using System.Net; using System.Windows; using System.Windows.Controls; using System.Windows.Documents; using System.Windows.Input; using System.Windows.Media; using System.Windows.Media.Animation; using System.Windows.Shapes; using System.Windows.Media.Imaging; //因为要使用BitmapImage using System.IO; //因为要使用Stream namespace HCLoad { public partial class UC_UpDown : UserControl { //1、WebClient 对象一次只能启动一个请求。如果在一个请求完成（包括出错和取消）前，即IsBusy为true时，进行第二个请求，则第二个请求将会抛出 NotSupportedException 类型的异常 //2、如果 WebClient 对象的 BaseAddress 属性不为空，则 BaseAddress 与 URI（相对地址） 组合在一起构成绝对 URI //3、WebClient 类的 AllowReadStreamBuffering 属性：是否对从 Internet 资源接收的数据做缓冲处理。默认值为true，将数据缓存在客户端内存中，以便随时被应用程序读取 //获取选定图片信息 System.IO.FileInfo fileinfo; public UC_UpDown() { InitializeComponent(); } #region 下载图片 private void btnDownload_Click(object sender, RoutedEventArgs e) { //向指定的Url发送下载流数据请求 String imgUrl = "http://localhost:4528/Bubble.jpg"; Uri endpoint = new Uri(imgUrl); WebClient client = new WebClient(); client.OpenReadCompleted += new OpenReadCompletedEventHandler(OnOpenReadCompleted); client.DownloadProgressChanged += new DownloadProgressChangedEventHandler(clientDownloadStream_DownloadProgressChanged); client.OpenReadAsync(endpoint); } void OnOpenReadCompleted(object sender, OpenReadCompletedEventArgs e) { //OpenReadCompletedEventArgs.Error - 该异步操作期间是否发生了错误 //OpenReadCompletedEventArgs.Cancelled - 该异步操作是否已被取消 //OpenReadCompletedEventArgs.Result - 下载后的 Stream 类型的数据 //OpenReadCompletedEventArgs.UserState - 用户标识 if (e.Error != null) { MessageBox.Show(e.Error.ToString()); return; } if (e.Cancelled != true) { //获取下载的流数据(在此处是图片数据)并显示在图片控件中 //Stream stream = e.Result; //BitmapImage bitmap = new BitmapImage(); //bitmap.SetSource(stream); //imgDownLoad.Source = bitmap; Stream clientStream = e.UserState as Stream; Stream serverStream = (Stream)e.Result; byte[] buffer = new byte[serverStream.Length]; serverStream.Read(buffer, 0, buffer.Length); clientStream.Write(buffer, 0, buffer.Length); clientStream.Close(); serverStream.Close(); } } void clientDownloadStream_DownloadProgressChanged(object sender, DownloadProgressChangedEventArgs e) { //DownloadProgressChangedEventArgs.ProgressPercentage - 下载完成的百分比 //DownloadProgressChangedEventArgs.BytesReceived - 当前收到的字节数 //DownloadProgressChangedEventArgs.TotalBytesToReceive - 总共需要下载的字节数 //DownloadProgressChangedEventArgs.UserState - 用户标识 this.tbMsgString.Text = string.Format("完成百分比：{0} 当前收到的字节数：{1} 资料大小：{2} ", e.ProgressPercentage.ToString() + "%", e.BytesReceived.ToString(), e.TotalBytesToReceive.ToString()); } #endregion #region 上传图片 private void btnUpLoad_Click(object sender, RoutedEventArgs e) { /**/ /* *　　 OpenWriteCompleted - 在打开用于上传的流完成时（包括取消操作及有错误发生时）所触发的事件 *　　 WriteStreamClosed - 在写入数据流的异步操作完成时（包括取消操作及有错误发生时）所触发的事件 *　　 UploadProgressChanged - 上传数据过程中所触发的事件。如果调用 OpenWriteAsync() 则不会触发此事件 *　　 Headers - 与请求相关的的标头的 key/value 对** *　　 OpenWriteAsync(Uri address, string method, Object userToken) - 打开流以使用指定的方法向指定的 URI 写入数据 *　　　　 Uri address - 接收上传数据的 URI *　　　　 string method - 所使用的 HTTP 方法（POST 或 GET） *　　　　 Object userToken - 需要上传的数据流 */ OpenFileDialog openFileDialog = new OpenFileDialog() { //弹出打开文件对话框要求用户自己选择在本地端打开的图片文件 Filter = "Jpeg Files (*.jpg)|*.jpg|All Files(*.*)|*.*", Multiselect = false //不允许多选 }; if (openFileDialog.ShowDialog() == true)//.DialogResult.OK) { //fileinfo = openFileDialog.Files; //取得所选择的文件，其中Name为文件名字段，作为绑定字段显示在前端 fileinfo = openFileDialog.File; if (fileinfo != null) { WebClient webclient = new WebClient(); string uploadFileName = fileinfo.Name.ToString(); //获取所选文件的名字 #region 把图片上传到服务器上 Uri upTargetUri = new Uri(String.Format("http://localhost:4528/WebClientUpLoadStreamHandler.ashx?fileName={0}", uploadFileName), UriKind.Absolute); //指定上传地址 webclient.OpenWriteCompleted += new OpenWriteCompletedEventHandler(webclient_OpenWriteCompleted); webclient.Headers["Content-Type"] = "multipart/form-data"; webclient.OpenWriteAsync(upTargetUri, "POST", fileinfo.OpenRead()); webclient.WriteStreamClosed += new WriteStreamClosedEventHandler(webclient_WriteStreamClosed); #endregion } else { MessageBox.Show("请选取想要上载的图片!!!"); } } } void webclient_OpenWriteCompleted(object sender, OpenWriteCompletedEventArgs e) { //将图片数据流发送到服务器上 // e.UserState - 需要上传的流（客户端流） Stream clientStream = e.UserState as Stream; // e.Result - 目标地址的流（服务端流） Stream serverStream = e.Result; byte[] buffer = new byte[4096]; int readcount = 0; // clientStream.Read - 将需要上传的流读取到指定的字节数组中 while ((readcount = clientStream.Read(buffer, 0, buffer.Length)) > 0) { // serverStream.Write - 将指定的字节数组写入到目标地址的流 serverStream.Write(buffer, 0, readcount); } serverStream.Close(); clientStream.Close(); } void webclient_WriteStreamClosed(object sender, WriteStreamClosedEventArgs e) { //判断写入是否有异常 if (e.Error != null) { System.Windows.Browser.HtmlPage.Window.Alert(e.Error.Message.ToString()); } else { System.Windows.Browser.HtmlPage.Window.Alert("图片上传成功!!!"); } } #endregion private void Button_Click(object sender, RoutedEventArgs e) { //这种方法搞不定，好像提示跨域操作。 //提示：错误：Unhandled Error in Silverlight Application 跨线程访问无效。 //Uri upTargetUri = new Uri(String.Format("http://localhost:4528/download.ashx?filename={0}", "123.jpg"), UriKind.Absolute); //指定上传地址 //WebRequest request = WebRequest.Create(upTargetUri); //request.Method = "GET"; //request.ContentType = "application/octet-stream"; //request.BeginGetResponse(new AsyncCallback(RequestReady), request); //通过调用js代码下载，比较简单。 System.Windows.Browser.HtmlPage.Window.Eval("window.location.href='http://localhost:4528/download.ashx?filename=123.jpg';"); } void RequestReady(IAsyncResult asyncResult) { MessageBox.Show("RequestComplete"); } } }

在HCLoad.Web项目下新建WebClientUpLoadStreamHandler.ashx

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using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.IO; //因为要用到Stream namespace HCLoad.Web { public class WebClientUpLoadStreamHandler : IHttpHandler { public void ProcessRequest(HttpContext context) { //获取上传的数据流 string fileNameStr = context.Request.QueryString["fileName"]; Stream sr = context.Request.InputStream; try { string filename = ""; filename = fileNameStr; byte[] buffer = new byte[4096]; int bytesRead = 0; //将当前数据流写入服务器端文件夹ClientBin下 string targetPath = context.Server.MapPath("Pics/" + filename + ".jpg"); using (FileStream fs = File.Create(targetPath, 4096)) { while ((bytesRead = sr.Read(buffer, 0, buffer.Length)) > 0) { //向文件中写信息 fs.Write(buffer, 0, bytesRead); } } context.Response.ContentType = "text/plain"; context.Response.Write("上传成功"); } catch (Exception e) { context.Response.ContentType = "text/plain"; context.Response.Write("上传失败, 错误信息:" + e.Message); } finally { sr.Dispose(); } } public bool IsReusable { get { return false; } } } }

新建download.ashx

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using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.Web.Services; using System.Net; namespace HCLoad.Web { /// <summary> /// $codebehindclassname$ 的摘要说明 /// </summary> public class download : IHttpHandler { private long ChunkSize = 102400;//100K 每次读取文件，只读取100Ｋ，这样可以缓解服务器的压力 public void ProcessRequest(HttpContext context) { //string fileName = "123.jpg";//客户端保存的文件名 String fileName = context.Request.QueryString["filename"]; string filePath = context.Server.MapPath("Bubble.jpg"); System.IO.FileInfo fileInfo = new System.IO.FileInfo(filePath); if (fileInfo.Exists == true) { byte[] buffer = new byte[ChunkSize]; context.Response.Clear(); System.IO.FileStream iStream = System.IO.File.OpenRead(filePath); long dataLengthToRead = iStream.Length;//获得下载文件的总大小 context.Response.ContentType = "application/octet-stream"; //通知浏览器下载文件而不是打开 context.Response.AddHeader("Content-Disposition", "attachment; filename=" + HttpUtility.UrlEncode(fileName, System.Text.Encoding.UTF8)); while (dataLengthToRead > 0 && context.Response.IsClientConnected) { int lengthRead = iStream.Read(buffer, 0, Convert.ToInt32(ChunkSize));//读取的大小 context.Response.OutputStream.Write(buffer, 0, lengthRead); context.Response.Flush(); dataLengthToRead = dataLengthToRead - lengthRead; } context.Response.Close(); context.Response.End(); } //context.Response.ContentType = "text/plain"; //context.Response.Write("Hello World"); } public bool IsReusable { get { return false; } } } }

参考：
http://www.cnblogs.com/wsdj-ittech/archive/2009/08/26/1554056.html
http://www.cnblogs.com/wsdj-ittech/archive/2009/08/25/1553534.html
http://www.cnblogs.com/wmt1708/archive/2009/03/07/1405009.html
http://topic.csdn.net/u/20090918/10/5e41ab52-f514-46b5-ae6a-d69ddb197213.html
http://www.cnblogs.com/wsdj-ittech/archive/2009/08/25/1553534.html
http://www.cnblogs.com/gwazy/archive/2009/04/02/1427781.html
http://www.cnblogs.com/ewyb/archive/2009/12/10/1621020.html
http://blog.csdn.net/emily1900/archive/2010/06/08/5655726.aspx