使用元帅vb.net Visual Studio 2012

Question

It says marshal cannot be used, because it's protection level or the variable is been used before and it's been assigned to another value.

//code:
Imports System.Text.RegularExpressions
Imports System.Runtime.InteropServices
Public Class Form1
Dim int As Integer = 0
Public WithEvents Browser As WebBrowser
Public Declare Function GetAsyncKeyState Lib "user32.dll" (ByVal vKey As Int32) As UShort

#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

Public 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
    Dim Marshal
    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

Answer 1

Marshal is a reserved word; you cannot give a variable this name. Remove the Dim Marshal statement.