Form3.vb

Imports System.Runtime.InteropServices
Imports Microsoft.Win32
Public Class Form3
#Region "Using Proxy"
    <Runtime.InteropServices.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

    Public Structure Struct_INTERNET_PROXY_INFO
        Public dwAccessType As Integer
        Public proxy As IntPtr
        Public proxyBypass As IntPtr
    End Structure

    Private Sub UseProxy(ByVal strProxy As String)
        Const INTERNET_OPTION_PROXY As Integer = 38
        Const INTERNET_OPEN_TYPE_PROXY As Integer = 3

        Dim struct_IPI As Struct_INTERNET_PROXY_INFO

        struct_IPI.dwAccessType = INTERNET_OPEN_TYPE_PROXY
        struct_IPI.proxy = Marshal.StringToHGlobalAnsi(strProxy)
        struct_IPI.proxyBypass = Marshal.StringToHGlobalAnsi("local")

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

        Marshal.StructureToPtr(struct_IPI, intptrStruct, True)

        Dim iReturn As Boolean = InternetSetOption(IntPtr.Zero, INTERNET_OPTION_PROXY, intptrStruct, System.Runtime.InteropServices.Marshal.SizeOf(struct_IPI))
    End Sub
#End Region

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        UseProxy(TextBox1.Text & ":" & TextBox2.Text)
        Form1.wb.Navigate("ipchicken.com")

    End Sub

    Private Sub CheckBox1_CheckedChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles CheckBox1.CheckedChanged
        Form1.Show()
    End Sub

    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
        TextBox1.Text = ""
        TextBox2.Text = ""
        UseProxy(TextBox1.Text & ":" & TextBox2.Text)
        Form1.wb.Navigate("ipchicken.com")
        'Connect to the registry and disable the proxy
        Dim proxy As RegistryKey = Registry.CurrentUser.OpenSubKey("Software\Microsoft\Windows\CurrentVersion\Internet Settings", True)
        proxy.SetValue("ProxyEnable", 0)

    End Sub
End Class