private static void EnsureSubscribedToGlobalKeyboardEvents()
{
// 安装键盘钩子，只有当它没有安装，必须安装
if (s_KeyboardHookHandle == 0)
{
//var ss = Assembly.GetExecutingAssembly().GetModules();
var mo = HookApi.GetModuleHandle(Process.GetCurrentProcess().MainModule.ModuleName);
//为了避免GC把它清理干净。
s_KeyboardDelegate = KeyboardHookProc;
//安装钩子
s_KeyboardHookHandle = HookApi.SetWindowsHookEx(HookType.WH_KEYBOARD_LL, s_KeyboardDelegate, mo, 0);
// Marshal.GetHINSTANCE(Assembly.GetExecutingAssembly().GetModules()[0])
//如果SetWindowsHookEx函数将失败。
if (s_KeyboardHookHandle == 0)
{
//返回由上一个非托管函数使用平台调用称为具有DllImportAttribute.SetLastError标志设置返回的错误代码.
int errorCode = Marshal.GetLastWin32Error();
//初始化并抛出初始化Win32Exception类的新实例使用指定的错误。
throw new Win32Exception(errorCode);
}
}
}
private static void ForceUnsunscribeFromGlobalKeyboardEvents()
{
if (s_KeyboardHookHandle != 0)
{
//卸载钩子
int result = HookApi.UnhookWindowsHookEx(s_KeyboardHookHandle);
//重置句柄
s_KeyboardHookHandle = 0;
//清理
s_KeyboardDelegate = null;
//如果失败，异常必须抛出
if (result == 0)
{
int errorCode = Marshal.GetLastWin32Error();
throw new Win32Exception(errorCode);
}
}
}
/// <summary> 键盘检测活动将被称为每次回调函数。 </summary>
private static int KeyboardHookProc(int nCode, Int32 wParam, IntPtr lParam)
{
//表示如有underlaing事件设置e.Handled标志
bool handled = false;
if (nCode >= 0)
{
//在lParam中读取KeyboardHookStruct结构
KeyboardHookStruct MyKeyboardHookStruct = (KeyboardHookStruct)Marshal.PtrToStructure(lParam, typeof(KeyboardHookStruct));
if (s_KeyDown != null && (wParam == HookType.WM_KEYDOWN || wParam == HookType.WM_SYSKEYDOWN))
{
Keys keyData = (Keys)MyKeyboardHookStruct.VirtualKeyCode;
KeyEventArgs e = new KeyEventArgs(keyData);
s_KeyDown.Invoke(null, e);
handled = e.Handled;
}
// 按键按下
if (s_KeyPress != null && wParam == HookType.WM_KEYDOWN)
{
bool isDownShift = ((HookApi.GetKeyState(HookType.VK_SHIFT) & 0x80) == 0x80 ? true : false);
bool isDownCapslock = (HookApi.GetKeyState(HookType.VK_CAPITAL) != 0 ? true : false);
byte[] keyState = new byte[256];
HookApi.GetKeyboardState(keyState);
byte[] inBuffer = new byte[2];
if (HookApi.ToAscii(MyKeyboardHookStruct.VirtualKeyCode,
MyKeyboardHookStruct.ScanCode,
keyState,
inBuffer,
MyKeyboardHookStruct.Flags) == 1)
{
char key = (char)inBuffer[0];
if ((isDownCapslock ^ isDownShift) && Char.IsLetter(key))
{
key = Char.ToUpper(key);
}
KeyPressEventArgs e = new KeyPressEventArgs(key);
s_KeyPress.Invoke(null, e);
handled = handled || e.Handled;
}
}
// 按键弹起
if (s_KeyUp != null && (wParam == HookType.WM_KEYUP || wParam == HookType.WM_SYSKEYUP))
{
Keys keyData = (Keys)MyKeyboardHookStruct.VirtualKeyCode;
KeyEventArgs e = new KeyEventArgs(keyData);
s_KeyUp.Invoke(null, e);
handled = handled || e.Handled;
}
}
//如果事件在应用程序处理的不换手到其他听众
if (handled)
{
return(-1);
}
//转发到其它应用程序
return(HookApi.CallNextHookEx(s_KeyboardHookHandle, nCode, wParam, lParam));
}
