I have this Global Keyhook I found somewhere online which worked perfectly. Then when I updated to .NET 7.0 and Visual Studio 7.4, and migrated from UWP to the Windows App SDK with the .NET Upgrade Assistant It broke with an AccessViolationException!
Code:
public class KeyboardHook : IDisposable
{
bool Global = false;
public delegate void LocalKeyEventHandler(Keys key, bool Shift, bool Ctrl, bool Alt);
public event LocalKeyEventHandler KeyDown;
public event LocalKeyEventHandler KeyUp;
public delegate int CallbackDelegate(int Code, int W, int L);
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi)]
public struct KBDLLHookStruct
{
public Int32 vkCode;
public Int32 scanCode;
public Int32 flags;
public Int32 time;
public Int32 dwExtraInfo;
}
[DllImport("user32", CallingConvention = CallingConvention.StdCall)]
private static extern int SetWindowsHookEx(HookType idHook, CallbackDelegate lpfn, int hInstance, int threadId);
[DllImport("user32", CallingConvention = CallingConvention.StdCall)]
private static extern bool UnhookWindowsHookEx(int idHook);
[DllImport("user32", CallingConvention = CallingConvention.StdCall)]
private static extern int CallNextHookEx(int idHook, int nCode, int wParam, int lParam);
[DllImport("kernel32.dll", CallingConvention = CallingConvention.StdCall)]
private static extern int GetCurrentThreadId();
public enum HookType : int
{
WH_JOURNALRECORD = 0,
WH_JOURNALPLAYBACK = 1,
WH_KEYBOARD = 2,
WH_GETMESSAGE = 3,
WH_CALLWNDPROC = 4,
WH_CBT = 5,
WH_SYSMSGFILTER = 6,
WH_MOUSE = 7,
WH_HARDWARE = 8,
WH_DEBUG = 9,
WH_SHELL = 10,
WH_FOREGROUNDIDLE = 11,
WH_CALLWNDPROCRET = 12,
WH_KEYBOARD_LL = 13,
WH_MOUSE_LL = 14
}
private int HookID = 0;
CallbackDelegate TheHookCB = null;
//Start hook
public KeyboardHook(bool Global)
{
this.Global = Global;
TheHookCB = new CallbackDelegate(KeybHookProc);
if (Global)
{
HookID = SetWindowsHookEx(HookType.WH_KEYBOARD_LL, TheHookCB,
0, //0 for local hook. eller hwnd til user32 for global
0); //0 for global hook. eller thread for hooken
}
else
{
HookID = SetWindowsHookEx(HookType.WH_KEYBOARD, TheHookCB,
0, //0 for local hook. or hwnd to user32 for global
GetCurrentThreadId()); //0 for global hook. or thread for the hook
}
}
bool IsFinalized = false;
~KeyboardHook()
{
if (!IsFinalized)
{
UnhookWindowsHookEx(HookID);
IsFinalized = true;
}
}
public void Dispose()
{
if (!IsFinalized)
{
UnhookWindowsHookEx(HookID);
IsFinalized = true;
}
}
//The listener that will trigger events
private int KeybHookProc(int Code, int W, int L)
{
//KBDLLHookStruct LS = new KBDLLHookStruct();
if (Code < 0)
{
return CallNextHookEx(HookID, Code, W, L);
}
try
{
if (!Global)
{
if (Code == 3)
{
IntPtr ptr = IntPtr.Zero;
int keydownup = L >> 30;
if (keydownup == 0)
{
if (KeyDown != null) KeyDown((Keys)W, GetShiftPressed(), GetCtrlPressed(), GetAltPressed());
}
if (keydownup == -1)
{
if (KeyUp != null) KeyUp((Keys)W, GetShiftPressed(), GetCtrlPressed(), GetAltPressed());
}
//System.Diagnostics.Debug.WriteLine("Down: " + (Keys)W);
}
}
else
{
KeyEvents kEvent = (KeyEvents)W;
Int32 vkCode = Marshal.ReadInt32((IntPtr)L); //Error here!
if (kEvent != KeyEvents.KeyDown && kEvent != KeyEvents.KeyUp && kEvent != KeyEvents.SKeyDown && kEvent != KeyEvents.SKeyUp)
{
}
if (kEvent == KeyEvents.KeyDown || kEvent == KeyEvents.SKeyDown)
{
if (KeyDown != null) KeyDown((Keys)vkCode, GetShiftPressed(), GetCtrlPressed(), GetAltPressed());
}
if (kEvent == KeyEvents.KeyUp || kEvent == KeyEvents.SKeyUp)
{
if (KeyUp != null) KeyUp((Keys)vkCode, GetShiftPressed(), GetCtrlPressed(), GetAltPressed());
}
}
}
catch (Exception)
{
//Ignore all errors...
}
return CallNextHookEx(HookID, Code, W, L);
}
public enum KeyEvents
{
KeyDown = 0x0100,
KeyUp = 0x0101,
SKeyDown = 0x0104,
SKeyUp = 0x0105
}
[DllImport("user32.dll")]
static public extern short GetKeyState(System.Windows.Forms.Keys nVirtKey);
public static bool GetCapslock()
{
return Convert.ToBoolean(GetKeyState(System.Windows.Forms.Keys.CapsLock)) & true;
}
public static bool GetNumlock()
{
return Convert.ToBoolean(GetKeyState(System.Windows.Forms.Keys.NumLock)) & true;
}
public static bool GetScrollLock()
{
return Convert.ToBoolean(GetKeyState(System.Windows.Forms.Keys.Scroll)) & true;
}
public static bool GetShiftPressed()
{
int state = GetKeyState(System.Windows.Forms.Keys.ShiftKey);
if (state > 1 || state < -1) return true;
return false;
}
public static bool GetCtrlPressed()
{
int state = GetKeyState(System.Windows.Forms.Keys.ControlKey);
if (state > 1 || state < -1) return true;
return false;
}
public static bool GetAltPressed()
{
int state = GetKeyState(System.Windows.Forms.Keys.Menu);
if (state > 1 || state < -1) return true;
return false;
}
}
Error:
System.AccessViolationException
HResult=0x80004003
Message=Attempted to read or write protected memory. This is often an indication that other memory is corrupt.
- $exception {"Attempted to read or write protected memory. This is often an indication that other memory is corrupt."} System.AccessViolationException
+ Data {System.Collections.ListDictionaryInternal} System.Collections.IDictionary {System.Collections.ListDictionaryInternal}
HResult -2147467261 int
HelpLink null string
+ InnerException null System.Exception
Message "Attempted to read or write protected memory. This is often an indication that other memory is corrupt." string
Source null string
StackTrace null string
TargetSite null System.Reflection.MethodBase
+ Static members
+ Non-Public members
I have tried to try{} catch{} the exception but it didn't work
............................................................
EDIT: 23/NOV/2022:
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I have restored the project through the backup to it's original state, and instead added the Windows App SDK through NuGet and this error vanishes. Can anyone explain why?
