错误名称：ERROR_INVALID_HOOK_HANDLE
错误代码：1404（0x57C）
描述：钩子句柄无效。
我的问题是：
1）有人知道上述系统错误代码何时发生？
2）UnhookWindowsHookEx()函数能否导致上述系统代码？
我一直在谷歌搜索。但是，我找不到任何肯定的答案。 拜托，有人帮助我。
实际上，我正在开发一个与其他机器进行远程连接的应用程序。 该应用程序还监视用户在远程计算机上执行的操作。
为了监控用户的操作，我在连接到远程机器时为WH_KEYBOARD_LL和WH_MOUSE_LL挂钩安装了自定义挂钩程序。我使用SetWindowsHookEx（）方法安装了钩子程序。
以下代码包括WH_KEYBOARD_LL的自定义挂钩过程定义，并将该挂钩过程安装到WH_KEYBOARD_LL挂钩的挂钩链。
// custom keyboard hook procedure
private static int KeyboardHookProc(int nCode, Int32 wParam, IntPtr lParam)
{
//indicates if any of underlaing events set e.Handled flag
bool handled = false;
if (nCode >= 0)
{
//read structure KeyboardHookStruct at lParam
KeyboardHookStruct MyKeyboardHookStruct = (KeyboardHookStruct)Marshal.PtrToStructure(lParam, typeof(KeyboardHookStruct));
//raise KeyDown
if (s_KeyDown != null && (wParam == WM_KEYDOWN || wParam == WM_SYSKEYDOWN))
{
Keys keyData = (Keys)MyKeyboardHookStruct.VirtualKeyCode;
KeyEventArgs e = new KeyEventArgs(keyData);
s_KeyDown.Invoke(null, e);
handled = e.Handled;
}
// raise KeyPress
if (s_KeyPress != null && wParam == WM_KEYDOWN)
{
bool isDownShift = ((GetKeyState(VK_SHIFT) & 0x80) == 0x80 ? true : false);
bool isDownCapslock = (GetKeyState(VK_CAPITAL) != 0 ? true : false);
byte[] keyState = new byte[256];
GetKeyboardState(keyState);
byte[] inBuffer = new byte[2];
if (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;
}
}
// raise KeyUp
if (s_KeyUp != null && (wParam == WM_KEYUP || wParam == WM_SYSKEYUP))
{
Keys keyData = (Keys)MyKeyboardHookStruct.VirtualKeyCode;
KeyEventArgs e = new KeyEventArgs(keyData);
s_KeyUp.Invoke(null, e);
handled = handled || e.Handled;
}
}
//if event handled in application do not handoff to other listeners
if (handled)
return -1;
//forward to other application
return CallNextHookEx(s_KeyboardHookHandle, nCode, wParam, lParam);
}
// installing keyboard hook procedure
private static void EnsureSubscribedToGlobalKeyboardEvents()
{
// install Keyboard hook only if it is not installed and must be installed
if (s_KeyboardHookHandle == 0)
{
//See comment of this field. To avoid GC to clean it up.
s_KeyboardDelegate = KeyboardHookProc;
//install hook
s_KeyboardHookHandle = SetWindowsHookEx(
WH_KEYBOARD_LL,
s_KeyboardDelegate,
Marshal.GetHINSTANCE(
Assembly.GetExecutingAssembly().GetModules()[0]),
0);
//If SetWindowsHookEx fails.
if (s_KeyboardHookHandle == 0)
{
//Returns the error code returned by the last unmanaged function called using platform invoke that has the DllImportAttribute.SetLastError flag set.
int errorCode = Marshal.GetLastWin32Error();
//do cleanup
//Initializes and throws a new instance of the Win32Exception class with the specified error.
throw new Win32Exception(errorCode);
}
}
}
以下代码包括WH_MOUSE_LL的自定义挂钩过程定义，并将该挂钩过程安装到WH_MOUSE_LL挂钩的挂钩链。
// custom mouse hook procedure
private static int MouseHookProc(int nCode, int wParam, IntPtr lParam)
{
if (nCode >= 0)
{
//Marshall the data from callback.
MouseLLHookStruct mouseHookStruct = (MouseLLHookStruct)Marshal.PtrToStructure(lParam, typeof(MouseLLHookStruct));
//detect button clicked
MouseButtons button = MouseButtons.None;
short mouseDelta = 0;
int clickCount = 0;
bool mouseDown = false;
bool mouseUp = false;
switch (wParam)
{
case WM_LBUTTONDOWN:
mouseDown = true;
button = MouseButtons.Left;
clickCount = 1;
break;
case WM_LBUTTONUP:
mouseUp = true;
button = MouseButtons.Left;
clickCount = 1;
break;
case WM_LBUTTONDBLCLK:
button = MouseButtons.Left;
clickCount = 2;
break;
case WM_RBUTTONDOWN:
mouseDown = true;
button = MouseButtons.Right;
clickCount = 1;
break;
case WM_RBUTTONUP:
mouseUp = true;
button = MouseButtons.Right;
clickCount = 1;
break;
case WM_RBUTTONDBLCLK:
button = MouseButtons.Right;
clickCount = 2;
break;
case WM_MOUSEWHEEL:
//If the message is WM_MOUSEWHEEL, the high-order word of MouseData member is the wheel delta.
//One wheel click is defined as WHEEL_DELTA, which is 120.
//(value >> 16) & 0xffff; retrieves the high-order word from the given 32-bit value
mouseDelta = (short)((mouseHookStruct.MouseData >> 16) & 0xffff);
//TODO: X BUTTONS (I havent them so was unable to test)
//If the message is WM_XBUTTONDOWN, WM_XBUTTONUP, WM_XBUTTONDBLCLK, WM_NCXBUTTONDOWN, WM_NCXBUTTONUP,
//or WM_NCXBUTTONDBLCLK, the high-order word specifies which X button was pressed or released,
//and the low-order word is reserved. This value can be one or more of the following values.
//Otherwise, MouseData is not used.
break;
}
//generate event
MouseEventExtArgs e = new MouseEventExtArgs(
button,
clickCount,
mouseHookStruct.Point.X,
mouseHookStruct.Point.Y,
mouseDelta);
//Mouse up
if (s_MouseUp!=null && mouseUp)
{
s_MouseUp.Invoke(null, e);
}
//Mouse down
if (s_MouseDown != null && mouseDown)
{
s_MouseDown.Invoke(null, e);
}
//If someone listens to click and a click is heppened
if (s_MouseClick != null && clickCount>0)
{
s_MouseClick.Invoke(null, e);
}
//If someone listens to click and a click is heppened
if (s_MouseClickExt != null && clickCount > 0)
{
s_MouseClickExt.Invoke(null, e);
}
//If someone listens to double click and a click is heppened
if (s_MouseDoubleClick != null && clickCount == 2)
{
s_MouseDoubleClick.Invoke(null, e);
}
//Wheel was moved
if (s_MouseWheel!=null && mouseDelta!=0)
{
s_MouseWheel.Invoke(null, e);
}
//If someone listens to move and there was a change in coordinates raise move event
if ((s_MouseMove!=null || s_MouseMoveExt!=null) && (m_OldX != mouseHookStruct.Point.X || m_OldY != mouseHookStruct.Point.Y))
{
m_OldX = mouseHookStruct.Point.X;
m_OldY = mouseHookStruct.Point.Y;
if (s_MouseMove != null)
{
s_MouseMove.Invoke(null, e);
}
if (s_MouseMoveExt != null)
{
s_MouseMoveExt.Invoke(null, e);
}
}
if (e.Handled)
{
return -1;
}
}
//call next hook
return CallNextHookEx(s_MouseHookHandle, nCode, wParam, lParam);
}
// installing mouse hook procedure
private static void EnsureSubscribedToGlobalMouseEvents()
{
// install Mouse hook only if it is not installed and must be installed
if (s_MouseHookHandle == 0)
{
//See comment of this field. To avoid GC to clean it up.
s_MouseDelegate = MouseHookProc;
//install hook
s_MouseHookHandle = SetWindowsHookEx(
WH_MOUSE_LL,
s_MouseDelegate,
Marshal.GetHINSTANCE(
Assembly.GetExecutingAssembly().GetModules()[0]),
0);
//If SetWindowsHookEx fails.
if (s_MouseHookHandle == 0)
{
//Returns the error code returned by the last unmanaged function called using platform invoke that has the DllImportAttribute.SetLastError flag set.
int errorCode = Marshal.GetLastWin32Error();
//do cleanup
//Initializes and throws a new instance of the Win32Exception class with the specified error.
throw new Win32Exception(errorCode);
}
}
}
当用户从目标服务器断开连接时，我必须再次卸载这些挂钩程序。
以下是卸载WH_KEYBOARD_LL和WH_MOUSE_LL挂钩的挂钩程序的代码。
// uninstalling custom mouse hook procedure
private static void ForceUnsunscribeFromGlobalMouseEvents()
{
if (s_MouseHookHandle != 0)
{
//uninstall hook
int result = UnhookWindowsHookEx(s_MouseHookHandle);
//reset invalid handle
s_MouseHookHandle = 0;
//Free up for GC
s_MouseDelegate = null;
//if failed and exception must be thrown
if (result == 0)
{
//Returns the error code returned by the last unmanaged function called using platform invoke that has the DllImportAttribute.SetLastError flag set.
int errorCode = Marshal.GetLastWin32Error();
//Initializes and throws a new instance of the Win32Exception class with the specified error.
throw new Win32Exception(errorCode);
}
}
}
//uninstalling custom keyboard hook procedure
private static void ForceUnsunscribeFromGlobalKeyboardEvents()
{
if (s_KeyboardHookHandle != 0)
{
//uninstall hook
int result = UnhookWindowsHookEx(s_KeyboardHookHandle);
//reset invalid handle
s_KeyboardHookHandle = 0;
//Free up for GC
s_KeyboardDelegate = null;
//if failed and exception must be thrown
if (result == 0)
{
//Returns the error code returned by the last unmanaged function called using platform invoke that has the DllImportAttribute.SetLastError flag set.
int errorCode = Marshal.GetLastWin32Error();
//Initializes and throws a new instance of the Win32Exception class with the specified error.
throw new Win32Exception(errorCode);
}
}
}
当我卸载钩子程序时，我有时会得到Marshal.GetLastWin32Error（）返回的ERROR_INVALID_HOOK_HANDLE错误。但不总是。 我真的对此没有任何想法。所以，我试着在这篇文章中询问ERROR_INVALID_HOOK_HANDLE错误。