1    private void button1_Click(object sender, EventArgs e)
 2         {
 3 
 4             WebClient wc = new WebClient();
 5             wc.Credentials = new NetworkCredential("yzk", "123");
 6             using (Stream stream = wc.OpenRead("ftp://192.168.1.100/qq.xls"))
 7             {
 8 
 9                 //将网络流stream中的数据读取出来，存放到一个内存流
10                 //创建一个内存流
11                 using (MemoryStream ms = new MemoryStream())
12                 {
13                     //创建一个缓冲区byte[]
14                     byte[] byts = new byte[1024 * 1024];//1MB
15 
16                     while (true)
17                     {
18                         //从网络流中读取一部分数据到byts数组中
19                         //返回值为本次实际读取到的字节数
20                         int r = stream.Read(byts, 0, byts.Length);
21                         if (r <= 0)
22                         {
23                             break;
24                         }
25 
26                         //将本次读取到的数据写入到内存流中
27                         ms.Write(byts, 0, r);
28                     }
31                     //stream.Length
32                     //现在已经把stream中的数据都读取到了ms中。
33                     using (Workbook wk = new HSSFWorkbook(ms))
34                     {
35                         if (wk.NumberOfSheets > 0)
36                         {
37                             //获取第一个Sheet
38                             using (Sheet sheet = wk.GetSheetAt(0))
39                             {
40                                 MessageBox.Show(sheet.SheetName);
41                             }
42                         }
44                     }
47                 }
50             }
51         }