webbrowser实现一个进程一个代理的办法

public static void RefreshIESettings(string strProxy)
        {
            const int INTERNET_OPTION_PROXY = 38;
            const int INTERNET_OPEN_TYPE_PROXY = 3;
            //设置代理类型，直接访问，不需要通过代理服务器了
            const int INTERNET_OPEN_TYPE_DIRECT = 1;
            Struct_INTERNET_PROXY_INFO struct_IPI;
            struct_IPI.dwAccessType = INTERNET_OPEN_TYPE_PROXY;
            struct_IPI.proxy = Marshal.StringToHGlobalAnsi(strProxy);
            struct_IPI.proxyBypass = Marshal.StringToHGlobalAnsi("local");
            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;
            }
            Marshal.StructureToPtr(struct_IPI, intptrStruct, true);
            bool iReturn = InternetSetOption(IntPtr.Zero, INTERNET_OPTION_PROXY, intptrStruct, Marshal.SizeOf(struct_IPI));
        }

　　strProxy参数传空则为取消代理，传IP:端口则为设置本进程的HTTP代理，运行该方法后，本进程的所有http访问网页都会用这个代理去访问