winform 里 如何实现文件上传

看了网上写的 用webclient类的uploadfile方法，

我在本地建立了个webform,winform窗体,  现在可以本地实现文件传递，可以选择文件传到d:\temp路径下，但怎们传到服务器上就不会了

求教大神

webform code

 1 using System;
 2 using System.Collections.Generic;
 3 using System.Linq;
 4 using System.Web;
 5 using System.Web.UI;
 6 using System.Web.UI.WebControls;
 7 
 8 public partial class SiteMaster : System.Web.UI.MasterPage
 9 {
10     protected void Page_Load(object sender, EventArgs e)
11     {
12         foreach (string f in Request.Files.AllKeys)
13         {
14             HttpPostedFile file = Request.Files[f];
15             file.SaveAs(@"D:\Temp\" +file.FileName);
16         }
17         if (Request.Params["testKey"] != null)
18         {
19             Response.Write(Request.Params["testKey"]);
20         }  
21     }
22 }

winform code:

 1 using System;
 2 using System.Collections.Generic;
 3 using System.ComponentModel;
 4 using System.Data;
 5 using System.Drawing;
 6 using System.Linq;
 7 using System.Text;
 8 using System.Windows.Forms;
 9 using System.IO;
10 using System.Net;
11 using System.Web;
12 
13 namespace 上传
14 {
15     public partial class UpLoadForm : Form
16     {
17         public UpLoadForm()
18         {
19             InitializeComponent();
20         }
21         private void btn_select_Click(object sender, EventArgs e)
22         {
23             OpenFileDialog ofd = new OpenFileDialog();
24             ofd.Multiselect = true;
25             if (ofd.ShowDialog() == DialogResult.OK)
26             {
27                 this.txtpath.Text = ofd.FileName;
28             }
29         }
30         private void btn_Upload_Click(object sender, EventArgs e)
31         {
32             if (this.txtpath.EditValue != null)
33             {
34                UpLoadFile("http://localhost:61750/WebSite3/Default.aspx", "POST", this.txtpath.Text.Trim());
35                // UpLoadFile("\\192.168.5.71", "POST", this.txtpath.Text.Trim());
36             }
37             else
38             {
39                 MessageBox.Show("请选择上传文件");
40             }
41            
42         }
43         public void UpLoadFile(string Serverpath, string Mode, string Localpath)
44         {
45             try
46             {
47                 WebClient mywebcilent = new WebClient();                
48                 mywebcilent.UploadFile(Serverpath,Mode,Localpath);
49                 MessageBox.Show("上传成功");
50             }
51             catch
52             {
53                 MessageBox.Show("上传失败");
54             } 
55         }
56 
57     
58     }
59 }