Question

C#实现全局钩子的一点问题

我写了一些代码，编译的时候说setwindowsex可访问性不一致，应该如何解决？（由于字数限制，代码不完整）
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Runtime.InteropServices;
using System.Reflection;
using System.Diagnostics;

namespace hook
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}

#region 钩子类型枚举
internal enum HookType //枚举，钩子的类型
{
MsgFilter = -1,
JournalRecord = 0,
JournalPlayback = 1,
Keyboard = 2,
GetMessage = 3,
CallWndProc = 4,
CBT = 5,
SysMsgFilter = 6,
Mouse = 7,
Hardware = 8,
Debug = 9,
Shell = 10,
ForegroundIdle = 11,
CallWndProcRet = 12,
KeyboardLL = 13,
MouseLL = 14,
};
#endregion

IntPtr _nextHookPtr; //记录Hook编号

#region 必须的API

[DllImport("user32.dll", CharSet = CharSet.Auto,CallingConvention = CallingConvention.StdCall, SetLastError = true)]
protected static extern int SetWindowsHookEx(int idHook,HookProc lpfn,IntPtr hMod,int dwThreadId);

[DllImport("user32.dll", CharSet = CharSet.Auto, ExactSpelling = true)]
public static extern bool UnhookWindowsHookEx(IntPtr hhook);

[DllImport("user32.dll", CharSet = CharSet.Auto, ExactSpelling = true)]
public static extern IntPtr CallNextHookEx(IntPtr hhook, int code, IntPtr wparam, IntPtr lparam);

#endregion

internal delegate IntPtr HookProc(int code, IntPtr wparam, IntPtr lparam); //实现的委托

public IntPtr MyHookProc(int code, IntPtr wparam, IntPtr lparam)
{
//...你的代码
if (code < 0)
{
return CallNextHookEx(_nextHookPtr, code, wparam, lparam); //返回，让后面的程序处理该消息
}

if (wparam.ToInt32()==(int)Keys.A)
{
//to do
return (IntPtr)1; //直接返回了，该消息就处理结束了
}
else
{
return IntPtr.Zero;
}
}

public void SetHook()
{
if( _nextHookPtr != IntPtr.Zero ) //已经勾过了
{
return;
}

HookProc myhookProc = new HookProc(MyHookProc); //声明一个自己的Hook实现函数的委托对象
_nextHookPtr = SetWindowsHookEx(13, myhookProc,Marshal.GetHINSTANCE(Assembly.GetExecutingAssembly().GetModules()[0]), 0); //加到Hook链中

if (_nextHookPtr == IntPtr.Zero)
{
MessageBox.Show("安装钩子失败！");
}
}

Answer 1

protected static extern int SetWindowsHookEx(int idHook,HookProc lpfn,IntPtr hMod,int dwThreadId);

protected
改成
public