微软webbrowser控件也就是IE插件，他的所有功能就像IE类似，当然设置也是一样的，下面介绍下webbrowser如何设置代理

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Runtime.InteropServices;

namespace 网页刷新测试
{
    public partial class Form1 : Form
    {
        [DllImport("wininet.dll", SetLastError = true)]
        private static extern bool InternetSetOption(IntPtr hInternet, int dwOption, IntPtr lpBuffer, int lpdwBufferLength);

public Form1()
        {
            InitializeComponent();
            RefreshIESettings("183.203.12.21:80");
            webBrowser1.Navigate("http://www.sunwale.com/");

}

private void RefreshIESettings(string strProxy)
        {
            const int INTERNET_OPTION_PROXY = 38;
            const int INTERNET_OPEN_TYPE_PROXY = 3;

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));
        }

}

public struct Struct_INTERNET_PROXY_INFO
    {
        public int dwAccessType;
        public IntPtr proxy;
        public IntPtr proxyBypass;
    };

}