正文

Silverlight文件上传下载实现方法(下载保存)

︶ㄣSDDLL学院 メ
SDDLL学院V管理员 / 阅读
0708
这篇文章主要介绍了Silverlight文件上传下载实现方法(下载保存) ,需要的朋友可以参考下

这篇文章主要介绍了Silverlight文件上传下载实现方法(下载保存) ,需要的朋友可以参考下

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

?
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
<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

?
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
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

?
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
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

?
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
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