调用API为程序实例设置代理，VB

在《VB设置WebBrowser的COOKIE、临时文件夹等路径》一文中，我们介绍了为Webbrowser设置cookie路径的方法，同理可以为Webbrowser设置代理。但是如果程序中没有Webbrowser控件，用到了其他的网络功能，怎么设置代理呢？我们可以调用wininet.dll中的InternetSetOption函数。好了，直接给出核心代码。

'========================================

'声明作用：为本实例设置代理

'========================================

Private Const INTERNET_OPTION_PROXY = 38

Private Const URLMON_OPTION_USERAGENT = &H10000001

Private Const INTERNET_OPEN_TYPE_PROXY = 3

Private Const INTERNET_OPTION_SETTINGS_CHANGED = 39

Private Declare Sub UrlMkSetSessionOption Lib "urlmon.dll" (ByVal dwOption As Long, pbuffer As Any, ByVal dwBufferLength As Long, ByVal dwreserved As Long)

Private Type INTERNET_PROXY_INFO

dwAccessType As Long

lpszProxy As String

lpszProxyBypass As String

End Type

Private Declare Function InternetSetOption Lib "wininet.dll" _

Alias "InternetSetOptionA" _

(ByVal hInternet As Long, _

ByVal dwOption As Long, _

ByRef lpBuffer As Any, _

ByVal dwBufferLength As Long) As Long

'========================================

'函数名称：SetProxy

'函数作用：为本实例设置代理

'函数参数：比如SOCKS=127.0.0.1:1987

'========================================

Public Function SetProxy(ByVal Proxy As String)

Dim options As INTERNET_PROXY_INFO

options.dwAccessType = INTERNET_OPEN_TYPE_PROXY

options.lpszProxy = Proxy

options.lpszProxyBypass = ""

InternetSetOption 0, INTERNET_OPTION_PROXY, options, LenB(options)

InternetSetOption INTERNET_OPTION_SETTINGS_CHANGED, 0, 0, 0

End Function