C# webBrowser 使用ip代理访问网站

在做一些网站模拟操作或者用爬虫不断爬取同一个网站的数据时，有时候目标网站会设置一些防爬取策略，同一ip多次访问则会直接拦截，那么如果遇到这种情况我们如何绕过呢？ 答案显而易见直接换ip。最近用到了这方面的东西所以研究了一下，想着还是写个博客存一下，以防后面还会用到类似的功能。

效果如下：

代码如下：

        #region IP代理代码块
        public struct Struct_INTERNET_PROXY_INFO
        {
            public int dwAccessType;
            public IntPtr proxy;
            public IntPtr proxyBypass;
        };
        //strProxy为代理IP:端口
        private void RefreshIESettings(string strProxy)
        {
            const int INTERNET_OPTION_PROXY = 38;
            const int INTERNET_OPEN_TYPE_PROXY = 3;
            const int INTERNET_OPEN_TYPE_DIRECT = 1;

            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));
            if (string.IsNullOrEmpty(strProxy) || strProxy.Trim().Length == 0)
            {
                strProxy = string.Empty;
                struct_IPI.dwAccessType = INTERNET_OPEN_TYPE_DIRECT;

            }
            // Converting structure to IntPtr
            Marshal.StructureToPtr(struct_IPI, intptrStruct, true);

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

        [DllImport("wininet.dll", SetLastError = true)]
        private static extern bool InternetSetOption(IntPtr hInternet, int dwOption, IntPtr lpBuffer, int lpdwBufferLength);
        public class IEProxy
        {
            private const int INTERNET_OPTION_PROXY = 38;
            private const int INTERNET_OPEN_TYPE_PROXY = 3;
            private const int INTERNET_OPEN_TYPE_DIRECT = 1;

            private string ProxyStr;


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

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

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

            private bool InternetSetOption(string strProxy)
            {
                int bufferLength;
                IntPtr intptrStruct;
                Struct_INTERNET_PROXY_INFO struct_IPI;

                if (string.IsNullOrEmpty(strProxy) || strProxy.Trim().Length == 0)
                {
                    strProxy = string.Empty;
                    struct_IPI.dwAccessType = INTERNET_OPEN_TYPE_DIRECT;
                }
                else
                {
                    struct_IPI.dwAccessType = INTERNET_OPEN_TYPE_PROXY;
                }
                struct_IPI.proxy = Marshal.StringToHGlobalAnsi(strProxy);
                struct_IPI.proxyBypass = Marshal.StringToHGlobalAnsi("local");
                bufferLength = Marshal.SizeOf(struct_IPI);
                intptrStruct = Marshal.AllocCoTaskMem(bufferLength);
                Marshal.StructureToPtr(struct_IPI, intptrStruct, true);
                return InternetSetOption(IntPtr.Zero, INTERNET_OPTION_PROXY, intptrStruct, bufferLength);

            }
            public IEProxy(string strProxy)
            {
                this.ProxyStr = strProxy;
            }
            //设置代理
            public bool RefreshIESettings()
            {
                return InternetSetOption(this.ProxyStr);
            }
            //取消代理
            public bool DisableIEProxy()
            {
                return InternetSetOption(string.Empty);
            }
        }
     #endregion

使用教程：

        private void button8_Click(object sender, EventArgs e)
        {
            string proxy = this.textBox1.Text;
            RefreshIESettings(proxy);
            IEProxy ie = new IEProxy(proxy);
            ie.RefreshIESettings().ToString();

        }

        private void button9_Click(object sender, EventArgs e)
        {
            IEProxy ie = new IEProxy(null);
            ie.DisableIEProxy();

        }

        private void button10_Click(object sender, EventArgs e)
        {
            webBrowser1.Navigate("http://ie.icoa.cn/", null,null,null);
        }

注： textBox1.Text 代表的是代理ip+端口，格式为103.217.179.185:3128