#region 在线代理

         public struct Struct_INTERNET_PROXY_INFO

         {

             public int dwAccessType;

             public IntPtr proxy;

             public IntPtr proxyBypass;

         };

         /// <summary>

         /// 定义API函数

         /// </summary>

         /// <param name="hInternet"></param>

         /// <param name="dwOption"></param>

         /// <param name="lpBuffer"></param>

         /// <param name="lpdwBufferLength"></param>

         /// <returns></returns>

         [DllImport("wininet.dll", SetLastError = true)]

         private static extern bool InternetSetOption(IntPtr hInternet, int dwOption, IntPtr lpBuffer, int lpdwBufferLength);

         /// <summary>

         /// 刷新代理IP设置

         /// </summary>

         /// <param name="strProxy"></param>

         private void RefreshIESettings(string strProxy)

         {

             const int INTERNET_OPTION_PROXY = ;

             const int INTERNET_OPEN_TYPE_PROXY = ;

             Struct_INTERNET_PROXY_INFO struct_IPI;

             // Filling in structure

             struct_IPI.dwAccessType = INTERNET_OPEN_TYPE_PROXY;

             struct_IPI.proxy = Marshal.StringToHGlobalAnsi(strProxy);

             struct_IPI.proxyBypass = Marshal.StringToHGlobalAnsi("local");

             // Allocating memory

             IntPtr intptrStruct = Marshal.AllocCoTaskMem(Marshal.SizeOf(struct_IPI));

             // Converting structure to IntPtr

             Marshal.StructureToPtr(struct_IPI, intptrStruct, true);

             bool iReturn = InternetSetOption(IntPtr.Zero, INTERNET_OPTION_PROXY, intptrStruct, Marshal.SizeOf(struct_IPI));

         }

         /// <summary>

         /// 在线代理访问网页URL

         /// </summary>

         /// <param name="ip">代理IP</param>

         /// <param name="port">代理端口</param>

         /// <param name="url">要访问的网页URL</param>

         private void NaviByProxy(string ip, string port, string url)

         {

             ListViewItem item = this.lst.SelectedItems[];

             //this.listView_usr.Items.Remove(item);

             RefreshIESettings(string.Format("{0}:{1}", ip, port));

             System.Object nullObject = ;

             string strTemp = String.Empty;

             System.Object nullObjStr = strTemp;

             this.wbCnblog.Navigate(url);

         }

         #endregion

 调用NaviByProxy该方法，代理浏览网页：

                 if (lst.SelectedItems.Count > )

                 {

                     //代理游览网站URL

                     NaviByProxy(

                         lst.SelectedItems[].SubItems[].Text, //选中的代理IP地址

                         lst.SelectedItems[].SubItems[].Text, //选中的代理IP的端口

                         textBox_url.Text.Trim()//url地址

                         );

                 }

                 else wbCnblog.Navigate(textBox_url.Text);