C# 修改浏览器代理地址

参考地址 https://www.cnblogs.com/skybreak/p/3554229.html

调用方式为 :

IEProxy.SetProxy(strProxy);

可用的免费代理网站： 

http://www.xicidaili.com

http://www.ip3366.net

http://www.66ip.cn

 下方为修改代理的类：

namespace CatchDataFrame.Utils
{
    public class IEProxy
    {
        public static bool UnsetProxy()
        {
            return SetProxy(null, null);
        }

        public static bool SetProxy(string strProxy)
        {
            return SetProxy(strProxy, null);
        }

        public static bool SetProxy(string strProxy, string exceptions)
        {
            InternetPerConnOptionList list = new InternetPerConnOptionList();

            int optionCount = string.IsNullOrEmpty(strProxy) ? 1 : (string.IsNullOrEmpty(exceptions) ? 2 : 3);
            InternetConnectionOption[] options = new InternetConnectionOption[optionCount];
            //use  a proxy server
            options[0].M_Option = PerConnOption.INTERNET_PER_CONN_FLAGS;
            options[0].M_Value.M_Int = (int)((optionCount < 2) ? PerConnFlags.PROXY_TYPE_DIRECT :
                (PerConnFlags.PROXY_TYPE_DIRECT | PerConnFlags.PROXY_TYPE_PROXY));
            //use this proxy server
            if(optionCount>1)
            {
                options[1].M_Option = PerConnOption.INTERNET_PER_CONN_PROXY_SERVE;
                options[1].M_Value.M_StringPtr = Marshal.StringToHGlobalAuto(strProxy);
                //except for these addresses
                if(optionCount>2)
                {
                    options[2].M_Option = PerConnOption.INTERNET_PER_CONN_PROXY_BYPASS;
                    options[2].M_Value.M_StringPtr = Marshal.StringToHGlobalAuto(exceptions);
                }
            }

            //default stuff
            list.DwSize = Marshal.SizeOf(list);
            list.SzConnection = IntPtr.Zero;
            list.DwOptionCount = options.Length;
            list.DwOptionError = 0;

            int optSize = Marshal.SizeOf(typeof(InternetConnectionOption));
            //make a pointer out of all that
            IntPtr optionPtr = Marshal.AllocCoTaskMem(optSize * options.Length);
            //copy the array  over into that  spot in memory
            for(int i=0;i<options.Length;++i)
            {
                IntPtr opt = new IntPtr(optionPtr.ToInt32() + (i * optSize));
                Marshal.StructureToPtr(options[i], opt, false);
            }
            list.Options = optionPtr;

            //and then make a pointer out of the whole list
            IntPtr ipcoListPtr = Marshal.AllocCoTaskMem((Int32)list.DwSize);
            Marshal.StructureToPtr(list, ipcoListPtr, false);

            //finally,call the api mehod
            int returnvalue = NativeMethods.InternetSetOption(IntPtr.Zero,
                InternetOption.INTERNET_OPTION_PER_CONNECTION_OPTION,
                ipcoListPtr, list.DwSize) ? -1 : 0;
            if (returnvalue == 0)
            {
                //get the error codes,they might be helpful
                throw new Win32Exception(Marshal.GetLastWin32Error());
            }

            return (returnvalue < 0);
        }

    }

    #region WinInet structures

    [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
    public struct InternetPerConnOptionList
    {
        public int DwSize; //size of the INTERNET_PER_CONN_OPTION_LIST struct
        public IntPtr SzConnection; //connection name to set/query options
        public int DwOptionCount; //number of options to set/query
        public int DwOptionError; //on error ,which option failed
        public IntPtr Options;
    }

    [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
    public struct InternetConnectionOption
    {
        static readonly int Size;
        public PerConnOption M_Option;
        public InternetConnectionOptionValue M_Value;
        static InternetConnectionOption()
        {
            InternetConnectionOption.Size = Marshal.SizeOf(typeof(InternetConnectionOption));
        }

        //Nested types
        [StructLayout(LayoutKind.Explicit)]
        public struct InternetConnectionOptionValue
        {
            [FieldOffset(0)]
            public System.Runtime.InteropServices.ComTypes.FILETIME M_FileTime;

            [FieldOffset(0)]
            public int M_Int;

            [FieldOffset(0)]
            public IntPtr M_StringPtr;
        }
    }

    #endregion

    #region WinInet enums

    /// <summary>
    /// options manifests for Internet{Query|Set} Option
    /// </summary>
    public enum InternetOption : uint
    {
        INTERNET_OPTION_PER_CONNECTION_OPTION = 75
    }

    /// <summary>
    /// Options used in INTERNET_PER_CONN_OPTION struct
    /// </summary>
    public enum PerConnOption
    {
        /// <summary>
        /// Sets or retrieves the connection type.The vlaue member will contain one or more of the values from PerConnFlags
        /// </summary>
        INTERNET_PER_CONN_FLAGS = 1,
        /// <summary>
        /// Sets or retrieves a string containing the proxy servers 
        /// </summary>
        INTERNET_PER_CONN_PROXY_SERVE = 2,
        /// <summary>
        /// Sets or retrieves a string containing the urls what do not  user the proxy server 
        /// </summary>
        INTERNET_PER_CONN_PROXY_BYPASS = 3,
        /// <summary>
        /// Sets or retrieves a string containing the url to the automatic configuration script
        /// </summary>
        INTERNET_PER_CONN_AUTOCONFIG_URL = 4
    }

    /// <summary>
    /// PER_CONN_FLAGS
    /// </summary>
    [Flags]
    public enum PerConnFlags
    {
        PROXY_TYPE_DIRECT = 0x00000001, //direct to net 
        PROXY_TYPE_PROXY = 0x00000002, //via named proxy
        PROXY_TYPE_AUTO_PROXY_URL = 0x00000004, //autoproxy url
        PROXY_TYPE_AUTO_DETECT = 0x00000008 // use autoproxy detection
    }

    #endregion

    internal static class NativeMethods
    {
        [DllImport("WinInet.dll", SetLastError = true, CharSet = CharSet.Auto)]
        [return: MarshalAs(UnmanagedType.Bool)]
        public static extern bool InternetSetOption(IntPtr hInternet, InternetOption dwOption, IntPtr lpBuffer, int dwBufferLength);
    }

}

查验结果：

可通过各浏览器的设置-->代理-->连接-->局域网设置。查看修改后的代理地址。