silverlight webclient实现上传、下载、删除、读取文件

1.上传

  private void Button_Click_1(object sender, RoutedEventArgs e)
         {
             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 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 把文件上传到服务器上

                     Uri upTargetUri = new Uri(String.Format("http://localhost:" + HtmlPage.Document.DocumentUri.Port + "/WebClientUpLoadStreamHandler.ashx?fileName={0}", uploadFileName), UriKind.Absolute); //指定上传处理程序

                     webclient.OpenWriteCompleted += new OpenWriteCompletedEventHandler(webclient_OpenWriteCompleted);
                     webclient.Headers["Content-Type"] = "multipart/form-data";//"application/x-www-form-urlencoded";// 

                     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[clientStream.Length];
             int readcount = ;
             // 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, , buffer.Length)) > )
             {
                 // serverStream.Write - 将指定的字节数组写入到目标地址的流
                 serverStream.Write(buffer, , 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("文件上传成功!!!");
             }
         }

 using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
 using System.Web;

 namespace SilverlightApplication9.Web
 {
     /// <summary>
     /// WebClientUpLoadStreamHandler 的摘要说明
     /// </summary>
     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[];
                 int bytesRead = ;
                 //将当前数据流写入服务器端文件夹ClientBin下
                 string targetPath = context.Server.MapPath("Pics/" + filename);

                 using (FileStream fs = File.Create(targetPath, ))
                 {
                     while ((bytesRead = sr.Read(buffer, , buffer.Length)) > )
                     {
                         //向文件中写信息
                         fs.Write(buffer, , 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;
             }
         }
     }
 }

2.下载
2.1下载方法1

  #region  下载图片
         SaveFileDialog sfd = null;
         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:51896/Pics/Wildlife.wmv";
             Uri endpoint = new Uri(imgUrl);
             sfd = new SaveFileDialog()
             {
                 DefaultExt = "jpeg",
                 Filter = "Text files (*.jpeg)|*.jpeg|All files (*.*)|*.*",
                 FilterIndex =
             };

             if (sfd.ShowDialog() == true)
             {

                 Uri end1point = new Uri(imgUrl);
                 WebClient client = new WebClient();
                 client.OpenReadCompleted += (ss, ee) =>
                 {
                     Stream pngStream = ee.Result;
                     byte[] binaryData = new Byte[pngStream.Length];
                     pngStream.Read(binaryData, , (int)pngStream.Length);
                     Stream stream = sfd.OpenFile();
                     stream.Write(binaryData, , binaryData.Length);
                     stream.Close();

                 };
                 client.DownloadProgressChanged += new DownloadProgressChangedEventHandler(clientDownloadStream_DownloadProgressChanged);
                 client.OpenReadAsync(endpoint);
             }

         }

         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

2.2下载方法2

  private void btnDownload_Click(object sender, RoutedEventArgs e)
         {
             System.Windows.Browser.HtmlPage.Window.Eval("window.location.href='http://localhost:51896/download.ashx?filename=IMG_20140329_093302.jpg';");
 }

 using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Web;

 namespace SilverlightApplication9.Web
 {
     /// <summary>
     /// download 的摘要说明
     /// </summary>
     public class download : IHttpHandler
     {
         private long ChunkSize = ;//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(@"Pics/IMG_20140329_093302.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 >  && context.Response.IsClientConnected)
                 {
                     int lengthRead = iStream.Read(buffer, , Convert.ToInt32(ChunkSize));//读取的大小
                     context.Response.OutputStream.Write(buffer, , 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;
             }
         }
     }
 }

3.删除

  private void WebClientCommand(string isDeleteParam, int sort)
         {
             string uploadFileName = null;
             WebClient webclient = new WebClient();
                            Uri upTargetUri = new Uri(String.Format("http://localhost:" + HtmlPage.Document.DocumentUri.Port + "/WebClientUpLoadStreamHandler.ashx?fileName={0}&result={1}", uploadFileName, isDeleteParam), UriKind.Absolute);
                 webclient.UploadStringCompleted += webclient_UploadStringCompleted;
                 webclient.UploadStringAsync(upTargetUri,"");

         }

  void webclient_UploadStringCompleted(object sender, UploadStringCompletedEventArgs e)
         {
             if (e.Error == null)
             {
                 EasySL.Controls.Window.Alert("删除成功", this.floatePanel);
             }
         }

 using Huitu.Bjsq.Service;
 using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
 using System.Web;

 namespace EasySL.Web
 {
     /// <summary>
     /// WebClientUpLoadStreamHandler 的摘要说明
     /// </summary>
     public class WebClientUpLoadStreamHandler : IHttpHandler
     {
         public void ProcessRequest(HttpContext context)
         {
             //获取上传的数据流
             string fileNameStr = context.Request.QueryString["fileName"];
             string paramResult = context.Request.QueryString["result"];
             Stream sr = context.Request.InputStream;
             try
             {
                 string filename = "";
                 filename = fileNameStr;
                 byte[] buffer = new byte[];
                 int bytesRead = ;
                 if (!string.IsNullOrEmpty(paramResult))
                 {
                     foreach (string item in paramResult.Split('|'))
                     {
                         string paramDel = context.Server.MapPath("FileLoad/" + item);
                         if (File.Exists(paramDel))
                         {
                             File.Delete(paramDel);
                             context.Response.ContentType = "text/plain";
                             context.Response.Write("删除成功");
                         }
                     }
                 }
                 else
                 {
                     //将当前数据流写入服务器端文件夹ClientBin下
                     string targetPath = context.Server.MapPath("FileLoad/" + filename);
                     using (FileStream fs = File.Create(targetPath, ))
                     {
                         while ((bytesRead = sr.Read(buffer, , buffer.Length)) > )
                         {
                             //向文件中写信息
                             fs.Write(buffer, , 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;
             }
         }
     }
 }

4.对于处理上传大文件的处理

 <configuration>
     <system.web>
       <compilation debug="true" targetFramework="4.5" />
       <httpRuntime targetFramework="4.5" maxRequestLength="" executionTimeout="" />
     </system.web>
 </configuration>

5.将程序发布在iis上注意的问题（代码是VS服务器运行正常，但是发布到IIS后上传文件总是失败。后来发现，我发布到IIS的虚拟目录，所以路径变了。）

Uri uri = new Uri(string.Format("/DataHandler.ashx?filename={0}", fileName), UriKind.Relative);

//   Uri uri = new Uri("http://localhost/SEManage/UploadImg.ashx", UriKind.Absolute);
            WebClient client = new WebClient();

将Uri中的绝对路径，修改为相对路径

6.读取文件操作（.txt）

private void SetWeather()
{
    WebClient downReader = new WebClient();
downReader.Encoding = System.Text.Encoding.UTF8;
            downReader.OpenReadCompleted += (s, e) =>
            {
                if (e.Error == null)
                {
                    using (StreamReader reader = new StreamReader(e.Result))
                    {
                        string[] line = reader.ReadToEnd().Split('|');
                     }
                  }
                }
 downReader.OpenReadAsync(new Uri("../AppConfig/Weather.txt", UriKind.Relative));
}
   private void WeatherDispatcherTimer()
        {
            //创建计时器
            System.Windows.Threading.DispatcherTimer myWeatherTimer = new System.Windows.Threading.DispatcherTimer();
            //创建间隔时间
            myWeatherTimer.Interval = new TimeSpan(, , , );
            //创建到达间隔时间后需执行的函数
            myWeatherTimer.Tick += (ss, ee) =>
            {
                InitDataWeather();
            };
            myWeatherTimer.Start();
        }