一、声明Windows API 中的函数和常量
//键盘Hook结构函数
[StructLayout(LayoutKind.Sequential)]
public class KeyBoardHookStruct
{
public int vkCode;
public int scanCode;
public int flags;
public int time;
public int dwExtraInfo;
}
#region DllImport
//设置钩子
[DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]
public static extern int SetWindowsHookEx(int idHook, HookProc lpfn, IntPtr hInstance, int threadId);
[DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]
//抽掉钩子
public static extern bool UnhookWindowsHookEx(int idHook);
[DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]
//调用下一个钩子
public static extern int CallNextHookEx(int idHook, int nCode, IntPtr wParam, IntPtr lParam);
//取得模块句柄
[DllImport("kernel32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]
private static extern IntPtr GetModuleHandle(string lpModuleName);
//寻找目标进程窗口
[DllImport("USER32.DLL")]
public static extern IntPtr FindWindow(string lpClassName,
string lpWindowName);
//设置进程窗口到最前
[DllImport("USER32.DLL")]
public static extern bool SetForegroundWindow(IntPtr hWnd);
//模拟键盘事件
[DllImport("User32.dll")]
public static extern void keybd_event(Byte bVk, Byte bScan, Int32 dwFlags, Int32 dwExtraInfo);
//释放按键的常量
private const int KEYEVENTF_KEYUP =2;
本例所使用的函数比较少,它们都在系统的USER32.dll里,包括:设置和取消钩子、调用下一个钩子、导入进程、模拟键盘等等。我们依次导入它们。
这些函数的命名规范合理,几乎只根据函数名就能知道其功能。