How to change proxy settings under Internet Explorer using C++

• Download SetProxy.zip-7.29KB

Introduction

On the www you can find a lot of tools which helps you to quickly switch between different proxy servers while surfing the internet. Most of them allow you to change the Internet Explorer proxy settings on-the-fly, without having to go into the Properties dialog.

Manually you can change your IE proxy settings using the following steps:

• Open Internet Explorer
• From the Tools menu, choose Internet Options.
• Click the Connections Tab
• Click on Lan Settings button

Now you should have in front of your screen the following dialog box (this if you use IE7)

• Tick the box marked "Use a proxy server for your LAN ..."
• In the Address field type your proxy address and in the Port field type your proxy port
• Tick the box marked "Bypass proxy server for local addresses"
• Click the "OK" button

In the following sections I will explain how to do all this things programmatically using C++.

Set proxy settings under Internet Explorer using Win 32 API

The idea is very simple. First of all we are building a connection options list and we set this options using InternetSetOption.

The following function takes two parameters. char *proxyAdressStr which represent the proxy server address and char * connNameStr which represent your connection name(in case you want to set the proxy for your LAN this should be set NULL).

BOOL SetConnectionProxy(char * proxyAdressStr , char * connNameStr = NULL) { INTERNET_PER_CONN_OPTION_LIST conn_options; BOOL bReturn; DWORD dwBufferSize = sizeof(conn_options); conn_options.dwSize = dwBufferSize; conn_options.pszConnection = connNameStr;//NULL == LAN conn_options.dwOptionCount = 3; conn_options.pOptions = new INTERNET_PER_CONN_OPTION[3]; if(!conn_options.pOptions) return FALSE; conn_options.pOptions[0].dwOption = INTERNET_PER_CONN_FLAGS; conn_options.pOptions[0].Value.dwValue = PROXY_TYPE_DIRECT|PROXY_TYPE_PROXY; conn_options.pOptions[1].dwOption = INTERNET_PER_CONN_PROXY_SERVER; conn_options.pOptions[1].Value.pszValue = proxyAdressStr; conn_options.pOptions[2].dwOption = INTERNET_PER_CONN_PROXY_BYPASS; conn_options.pOptions[2].Value.pszValue = "local"; bReturn = InternetSetOption(NULL,INTERNET_OPTION_PER_CONNECTION_OPTION, &conn_options, dwBufferSize); delete [] conn_options.pOptions; InternetSetOption(NULL, INTERNET_OPTION_SETTINGS_CHANGED, NULL, 0); InternetSetOption(NULL, INTERNET_OPTION_REFRESH , NULL, 0); return bReturn; }

Remove proxy settings under Internet Explorer using Win 32 API

The following function will remove your proxy settings for a specified connection name. In case you want to remove your LAN proxy settings set char *connectionNameStr as NULL.

BOOL RemoveConnectionProxy(char* connectionNameStr = NULL) { INTERNET_PER_CONN_OPTION_LIST conn_options; BOOL bReturn; DWORD dwBufferSize = sizeof(conn_options); conn_options.dwSize = dwBufferSize; conn_options.pszConnection = connectionNameStr; //NULL - LAN conn_options.dwOptionCount = 1; conn_options.pOptions = new INTERNET_PER_CONN_OPTION[conn_options.dwOptionCount]; if(!conn_options.pOptions) return FALSE; conn_options.pOptions[0].dwOption = INTERNET_PER_CONN_FLAGS; conn_options.pOptions[0].Value.dwValue = PROXY_TYPE_DIRECT ; bReturn = InternetSetOption(NULL,INTERNET_OPTION_PER_CONNECTION_OPTION, &conn_options, dwBufferSize); delete [] conn_options.pOptions; InternetSetOption(NULL, INTERNET_OPTION_SETTINGS_CHANGED, NULL, 0); InternetSetOption(NULL, INTERNET_OPTION_REFRESH , NULL, 0); return bReturn; }

Using this code

To use the functions described in this article you should include windows.h and wininet.h. Also you must link wininet.lib to your project.All these things can be done by adding the following three lines to your project:

#include <windows.h> #include <wininet.h> #pragma comment(lib,"wininet.lib")

License

This article, along with any associated source code and files, is licensed under The Intelliproject Open License (IPOL)

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