Public Class Form1
<StructLayout(LayoutKind.Sequential)> _
Public Structure Struct_INTERNET_PROXY_INFO
Public dwAccessType As Integer
Public proxy As IntPtr
Public proxyBypass As IntPtr
End Structure

<DllImport("wininet.dll ",SetLastError:=True)> _
Private Shared Function InternetSetOption( _
ByVal hInternet As IntPtr,_
ByVal dwOption As Integer,_
ByVal lpBuffer As IntPtr,_
ByVal lpdwBufferLength As Integer) _
As Boolean
End Function

Private Function RefreshIESettings(ByVal strProxy As String) As Boolean
Dim INTERNET_OPTION_PROXY As Integer = 38
Dim INTERNET_OPEN_TYPE_PROXY As Integer = 3

Dim struct_IPI As Struct_INTERNET_PROXY_INFO

'Filling in structure
struct_IPI.dwAccessType = INTERNET_OPEN_TYPE_PROXY
struct_IPI.proxy = Marshal.StringToHGlobalAnsi(strProxy)
struct_IPI.proxyBypass = Marshal.StringToHGlobalAnsi("local ")

'Allocating memory
Dim intptrStruct As IntPtr = Marshal.AllocCoTaskMem(Marshal.SizeOf(struct_IPI))

'Converting structure to IntPtr
Marshal.StructureToPtr(struct_IPI,intptrStruct,True)

Return InternetSetOption(IntPtr.Zero,INTERNET_OPTION_PROXY,Marshal.SizeOf(struct_IPI))
End Function

Private Sub Button1_Click(ByVal sender As System.Object,ByVal e As System.EventArgs) Handles Button1.Click
RefreshIESettings("192.168.1.150:8080) '使用 IP:端口
WebBrowser1.Navigate(" http://www.ip138.com")
End Sub

End Class