Get keypresses at low-level - c#

I am currently developing an operating system using the MOSA-OS compiler to compile CIL to machine code. Unfortunately, while developing an operating system it is not so simple to just "Console.ReadLine" to get input. Nothing from System.Console is working, and I can't use WinForms either. Is there an alternative way to get keypresses/input?

Hooking into the user32.dll is a great way. Here is a low-level keyboard listener that will do the job. All you need to do is call HookKeyboard() and listen for the OnKeyPressed event.
using System;
using System.Diagnostics;
using System.Runtime.InteropServices;
using System.Windows.Input;
namespace DesktopWPFAppLowLevelKeyboardHook
{
public class LowLevelKeyboardListener
{
private const int WH_KEYBOARD_LL = 13;
private const int WM_KEYDOWN = 0x0100;
private const int WM_SYSKEYDOWN = 0x0104;
[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
private static extern IntPtr SetWindowsHookEx(int idHook, LowLevelKeyboardProc lpfn, IntPtr hMod, uint dwThreadId);
[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
[return: MarshalAs(UnmanagedType.Bool)]
private static extern bool UnhookWindowsHookEx(IntPtr hhk);
[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
private static extern IntPtr CallNextHookEx(IntPtr hhk, int nCode, IntPtr wParam, IntPtr lParam);
[DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)]
private static extern IntPtr GetModuleHandle(string lpModuleName);
public delegate IntPtr LowLevelKeyboardProc(int nCode, IntPtr wParam, IntPtr lParam);
public event EventHandler<KeyPressedArgs> OnKeyPressed;
private LowLevelKeyboardProc _proc;
private IntPtr _hookID = IntPtr.Zero;
public LowLevelKeyboardListener()
{
_proc = HookCallback;
}
public void HookKeyboard()
{
_hookID = SetHook(_proc);
}
public void UnHookKeyboard()
{
UnhookWindowsHookEx(_hookID);
}
private IntPtr SetHook(LowLevelKeyboardProc proc)
{
using (Process curProcess = Process.GetCurrentProcess())
using (ProcessModule curModule = curProcess.MainModule)
{
return SetWindowsHookEx(WH_KEYBOARD_LL, proc, GetModuleHandle(curModule.ModuleName), 0);
}
}
private IntPtr HookCallback(int nCode, IntPtr wParam, IntPtr lParam)
{
if (nCode >= 0 && wParam == (IntPtr)WM_KEYDOWN || wParam == (IntPtr)WM_SYSKEYDOWN)
{
int vkCode = Marshal.ReadInt32(lParam);
if (OnKeyPressed != null) { OnKeyPressed(this, new KeyPressedArgs(KeyInterop.KeyFromVirtualKey(vkCode))); }
}
return CallNextHookEx(_hookID, nCode, wParam, lParam);
}
}
public class KeyPressedArgs : EventArgs
{
public Key KeyPressed { get; private set; }
public KeyPressedArgs(Key key)
{
KeyPressed = key;
}
}
}

Related

Globally Detecting Key Presses and Mouse Clicks

I am attempting to create a program to globally detect key presses and mouse clicks. I have googled around and found solutions for both and got them working in the same program. But I would like to combine the two separate classes into one class that does both. I have fiddled around with it for a bit and can't figure out how to do it. Does anyone know how to solve this? Thanks in advance!
Mouse clicks class:
public static class MouseHook
{
public static event EventHandler imputAction = delegate { };
public static void Start()
{
_hookID = SetHook(_proc);
}
public static void stop()
{
UnhookWindowsHookEx(_hookID);
}
private static LowLevelMouseProc _proc = HookCallback;
private static IntPtr _hookID = IntPtr.Zero;
private static IntPtr SetHook(LowLevelMouseProc proc)
{
using (Process curProcess = Process.GetCurrentProcess())
using (ProcessModule curModule = curProcess.MainModule)
{
return SetWindowsHookEx(WH_MOUSE_LL, proc,
GetModuleHandle(curModule.ModuleName), 0);
}
}
private delegate IntPtr LowLevelMouseProc(int nCode, IntPtr wParam, IntPtr lParam);
private static IntPtr HookCallback(
int nCode, IntPtr wParam, IntPtr lParam)
{
if (nCode >= 0 && MouseMessages.WM_LBUTTONDOWN == (MouseMessages)wParam)
{
MyGlobals.clickType = 1;
imputAction(null, new EventArgs());
}
if (nCode >= 0 && MouseMessages.WM_RBUTTONDOWN == (MouseMessages)wParam)
{
MyGlobals.clickType = 2;
imputAction(null, new EventArgs());
}
return CallNextHookEx(_hookID, nCode, wParam, lParam);
}
private const int WH_MOUSE_LL = 14;
private enum MouseMessages
{
WM_LBUTTONDOWN = 0x0201,
WM_RBUTTONDOWN = 0x0204,
}
[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
private static extern IntPtr SetWindowsHookEx(int idHook,
LowLevelMouseProc lpfn, IntPtr hMod, uint dwThreadId);
[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
[return: MarshalAs(UnmanagedType.Bool)]
private static extern bool UnhookWindowsHookEx(IntPtr hhk);
[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
private static extern IntPtr CallNextHookEx(IntPtr hhk, int nCode,
IntPtr wParam, IntPtr lParam);
[DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)]
private static extern IntPtr GetModuleHandle(string lpModuleName);
}
Keyboard class:
class InterceptKeys
{
private const int WH_KEYBOARD_LL = 13;
private const int WM_KEYDOWN = 0x0100;
private static LowLevelKeyboardProc _proc = HookCallback;
private static IntPtr _hookID = IntPtr.Zero;
public static event EventHandler imputAction = delegate { };
public static void Start()
{
_hookID = SetHook(_proc);
}
public static void stop()
{
UnhookWindowsHookEx(_hookID);
}
private static IntPtr SetHook(LowLevelKeyboardProc proc)
{
using (Process curProcess = Process.GetCurrentProcess())
using (ProcessModule curModule = curProcess.MainModule)
{
return SetWindowsHookEx(WH_KEYBOARD_LL, proc,
GetModuleHandle(curModule.ModuleName), 0);
}
}
private delegate IntPtr LowLevelKeyboardProc(
int nCode, IntPtr wParam, IntPtr lParam);
private static IntPtr HookCallback(
int nCode, IntPtr wParam, IntPtr lParam)
{
if (nCode >= 0 && wParam == (IntPtr)WM_KEYDOWN)
{
int vkCode = Marshal.ReadInt32(lParam);
MyGlobals.characters = Convert.ToString((Keys)vkCode);
MyGlobals.clickType = 3;
imputAction(null, new EventArgs());
}
return CallNextHookEx(_hookID, nCode, wParam, lParam);
}
[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
private static extern IntPtr SetWindowsHookEx(int idHook,
LowLevelKeyboardProc lpfn, IntPtr hMod, uint dwThreadId);
[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
[return: MarshalAs(UnmanagedType.Bool)]
private static extern bool UnhookWindowsHookEx(IntPtr hhk);
[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
private static extern IntPtr CallNextHookEx(IntPtr hhk, int nCode,
IntPtr wParam, IntPtr lParam);
[DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)]
private static extern IntPtr GetModuleHandle(string lpModuleName);
}
I am starting these like this:
MouseHook.Start();
MouseHook.MouseAction += new EventHandler(Event);
InterceptKeys.Start();
InterceptKeys.MouseAction += new EventHandler(Event)
The function receiving both events:
private void Event(object sender, EventArgs e)
{
//do stuff
}
I am also trying to do scrolling, I got it to detect scrolling by adding these lines. But I can't figure out how to read the scroll direction or value and assign it to a variable.
WM_MOUSEWHEEL = 0x020A,
if (nCode >= 0 && MouseMessages.WM_MOUSEWHEEL == (MouseMessages)wParam)
{
MyGlobals.imputType = 4;
// Here is where I need to set a variable to the direction or
// value of scrolling but I cant figure out how
imputAction(null, new EventArgs());
}

Any method to count Windows click count (C#)?

I'm trying to write a simple app that counts every mouse click that occurs in Windows (left and right separated), not only within a form. So far i did not have any success in finding such solution. Thanks!
You will need to use the Win32 Hook API to capture mouse events. Stephen Toub provides a nice bit of sample code on his MSDN blog post about setting up a mouse hook.
class InterceptMouse
{
private static LowLevelMouseProc _proc = HookCallback;
private static IntPtr _hookID = IntPtr.Zero;
public static void Main()
{
_hookID = SetHook(_proc);
Application.Run();
UnhookWindowsHookEx(_hookID);
}
private static IntPtr SetHook(LowLevelMouseProc proc)
{
using (Process curProcess = Process.GetCurrentProcess())
using (ProcessModule curModule = curProcess.MainModule)
{
return SetWindowsHookEx(WH_MOUSE_LL, proc,
GetModuleHandle(curModule.ModuleName), 0);
}
}
private delegate IntPtr LowLevelMouseProc(int nCode, IntPtr wParam, IntPtr lParam);
private static IntPtr HookCallback(
int nCode, IntPtr wParam, IntPtr lParam)
{
if (nCode >= 0 &&
MouseMessages.WM_LBUTTONDOWN == (MouseMessages)wParam)
{
MSLLHOOKSTRUCT hookStruct = (MSLLHOOKSTRUCT)Marshal.PtrToStructure(lParam, typeof(MSLLHOOKSTRUCT));
Console.WriteLine(hookStruct.pt.x + ", " + hookStruct.pt.y);
}
return CallNextHookEx(_hookID, nCode, wParam, lParam);
}
private const int WH_MOUSE_LL = 14;
private enum MouseMessages
{
WM_LBUTTONDOWN = 0x0201,
WM_LBUTTONUP = 0x0202,
WM_MOUSEMOVE = 0x0200,
WM_MOUSEWHEEL = 0x020A,
WM_RBUTTONDOWN = 0x0204,
WM_RBUTTONUP = 0x0205
}
[StructLayout(LayoutKind.Sequential)]
private struct POINT
{
public int x;
public int y;
}
[StructLayout(LayoutKind.Sequential)]
private struct MSLLHOOKSTRUCT
{
public POINT pt;
public uint mouseData;
public uint flags;
public uint time;
public IntPtr dwExtraInfo;
}
[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
private static extern IntPtr SetWindowsHookEx(int idHook,
LowLevelMouseProc lpfn, IntPtr hMod, uint dwThreadId);
[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
[return: MarshalAs(UnmanagedType.Bool)]
private static extern bool UnhookWindowsHookEx(IntPtr hhk);
[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
private static extern IntPtr CallNextHookEx(IntPtr hhk, int nCode,
IntPtr wParam, IntPtr lParam);
[DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)]
private static extern IntPtr GetModuleHandle(string lpModuleName);
}
In your code you would set this up to record WM_LBUTTONDOWN and WM_RBUTTONDOWN events.

Detect WM_MOUSEMOVE on different window

While my C# WinForms app is running, I need to detect when the mouse pointer is moved over a 3rd party application.
I've done some Google'ing but I can't seem to find a useful code example that shows how to set up a Hook Procedure to another application using C# to detect Windows Messages.
Can someone please show me how to setup a C# hook procedure so I can detect the WM_MOUSEMOVE message on another app (e.g. Notepad.exe)?
Below is the C# Low Level Mouse Hook code I was looking for, from the blogs.msdn.com/b/toub/archive/2006/05/03/589468.aspx link (that David Heffernan posted)
class InterceptMouse
{
private static LowLevelMouseProc _proc = HookCallback;
private static IntPtr _hookID = IntPtr.Zero;
public static void Main()
{
_hookID = SetHook(_proc);
Application.Run();
UnhookWindowsHookEx(_hookID);
}
private static IntPtr SetHook(LowLevelMouseProc proc)
{
using (Process curProcess = Process.GetCurrentProcess())
using (ProcessModule curModule = curProcess.MainModule)
{
return SetWindowsHookEx(WH_MOUSE_LL, proc,
GetModuleHandle(curModule.ModuleName), 0);
}
}
private delegate IntPtr LowLevelMouseProc(int nCode, IntPtr wParam, IntPtr lParam);
private static IntPtr HookCallback(
int nCode, IntPtr wParam, IntPtr lParam)
{
if (nCode >= 0 &&
MouseMessages.WM_LBUTTONDOWN == (MouseMessages)wParam)
{
MSLLHOOKSTRUCT hookStruct = (MSLLHOOKSTRUCT)Marshal.PtrToStructure(lParam, typeof(MSLLHOOKSTRUCT));
Console.WriteLine(hookStruct.pt.x + ", " + hookStruct.pt.y);
}
return CallNextHookEx(_hookID, nCode, wParam, lParam);
}
private const int WH_MOUSE_LL = 14;
private enum MouseMessages
{
WM_LBUTTONDOWN = 0x0201,
WM_LBUTTONUP = 0x0202,
WM_MOUSEMOVE = 0x0200,
WM_MOUSEWHEEL = 0x020A,
WM_RBUTTONDOWN = 0x0204,
WM_RBUTTONUP = 0x0205
}
[StructLayout(LayoutKind.Sequential)]
private struct POINT
{
public int x;
public int y;
}
[StructLayout(LayoutKind.Sequential)]
private struct MSLLHOOKSTRUCT
{
public POINT pt;
public uint mouseData;
public uint flags;
public uint time;
public IntPtr dwExtraInfo;
}
[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
private static extern IntPtr SetWindowsHookEx(int idHook,
LowLevelMouseProc lpfn, IntPtr hMod, uint dwThreadId);
[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
[return: MarshalAs(UnmanagedType.Bool)]
private static extern bool UnhookWindowsHookEx(IntPtr hhk);
[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
private static extern IntPtr CallNextHookEx(IntPtr hhk, int nCode,
IntPtr wParam, IntPtr lParam);
[DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)]
private static extern IntPtr GetModuleHandle(string lpModuleName);
}

Differentiate between two keyboards in a KeyboardHook

I got this program:
https://learn.microsoft.com/en-us/archive/blogs/toub/low-level-keyboard-hook-in-c
using System;
using System.Diagnostics;
using System.Windows.Forms;
using System.Runtime.InteropServices;
namespace KeyboardInput
{
class InterceptKeys
{
private delegate IntPtr LowLevelKeyboardProc(int nCode, IntPtr wParam, IntPtr lParam);
private const int WH_KEYBOARD_LL = 13;
private const int WM_KEYDOWN = 0x0100;
private static LowLevelKeyboardProc _proc = HookCallback;
private static IntPtr _hookID = IntPtr.Zero;
static void Main(string[] args)
{
_hookID = SetHook(_proc);
Application.Run();
UnhookWindowsHookEx(_hookID);
}
private static IntPtr SetHook(LowLevelKeyboardProc proc)
{
using (Process curProcess = Process.GetCurrentProcess())
using (ProcessModule curModule = curProcess.MainModule)
{
return SetWindowsHookEx(WH_KEYBOARD_LL, proc,
GetModuleHandle(curModule.ModuleName), 0);
}
}
private static IntPtr HookCallback(int nCode, IntPtr wParam, IntPtr lParam)
{
if (nCode >= 0 && wParam == (IntPtr)WM_KEYDOWN)
{
int vkCode = Marshal.ReadInt32(lParam);
Console.WriteLine((Keys)vkCode + " " + nCode + " " + wParam + " " + lParam);
}
return CallNextHookEx(_hookID, nCode, wParam, lParam);
}
[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
private static extern IntPtr SetWindowsHookEx(int idHook, LowLevelKeyboardProc lpfn, IntPtr hMod, uint dwThreadId);
[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
[return: MarshalAs(UnmanagedType.Bool)]
private static extern bool UnhookWindowsHookEx(IntPtr hhk);
[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
private static extern IntPtr CallNextHookEx(IntPtr hhk, int nCode, IntPtr wParam, IntPtr lParam);
[DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)]
private static extern IntPtr GetModuleHandle(string lpModuleName);
}
}
It captures keyboard input, but what I want is to be able to differentiate between two keyboards. I'd like to know if the key pressed was from the keyboard on my laptop or the keyboard that's connected via an USB.
How do I accomplish this?
To distinguish between input devices, you may probably need to use Raw Input API
Here is a detailed example
UPDATE: The above link seems to be down. But here is a similar question answered by the blogger who provided above example.

Global keyboard hook works, but global shell hook fails

I have two pieces of code which are very similar in that they register global hooks.
Registering global keyboard hook:
public class KeyboardHook : IDisposable
{
#region Events
private delegate IntPtr LowLevelKeyboardProc(int nCode, IntPtr wParam, IntPtr lParam);
public delegate void HookEventHandler(object sender, KeyboardHookEventArgs e);
public event HookEventHandler KeyDown;
public event HookEventHandler KeyUp;
#endregion
#region Constants
private const int WH_KEYBOARD_LL = 13;
private const int WM_KEYDOWN = 0x0100;
private const int WM_SYSKEYDOWN = 0x0104;
private LowLevelKeyboardProc _proc = null;
private static IntPtr _hookID = IntPtr.Zero;
#endregion
#region Imports
[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
private static extern IntPtr SetWindowsHookEx(int idHook,
LowLevelKeyboardProc lpfn, IntPtr hMod, uint dwThreadId);
[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
[return: MarshalAs(UnmanagedType.Bool)]
private static extern bool UnhookWindowsHookEx(IntPtr hhk);
[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
private static extern IntPtr CallNextHookEx(IntPtr hhk, int nCode,
IntPtr wParam, IntPtr lParam);
[DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)]
private static extern IntPtr GetModuleHandle(string lpModuleName);
#endregion
#region Constructor
public KeyboardHook()
{
_proc = new LowLevelKeyboardProc(HookCallback);
_hookID = SetHook(_proc);
}
#endregion
#region Methods
private IntPtr SetHook(LowLevelKeyboardProc proc)
{
using (Process curProcess = Process.GetCurrentProcess())
using (ProcessModule curModule = curProcess.MainModule)
{
return SetWindowsHookEx(WH_KEYBOARD_LL, proc,
GetModuleHandle(curModule.ModuleName), 0);
}
}
private IntPtr HookCallback(int nCode, IntPtr wParam, IntPtr lParam)
{
//if (nCode >= 0 && wParam == (IntPtr)WM_KEYDOWN)
if (nCode >= 0 && (wParam == (IntPtr)WM_KEYDOWN || wParam == (IntPtr)WM_SYSKEYDOWN))
{
int vkCode = Marshal.ReadInt32(lParam);
WinForms.Keys key = (WinForms.Keys)vkCode;
if (this.KeyDown != null)
this.KeyDown(this, new KeyboardHookEventArgs(vkCode));
}
return CallNextHookEx(_hookID, nCode, wParam, lParam);
}
#endregion
#region Destructor
public void Dispose()
{
UnhookWindowsHookEx(_hookID);
}
#endregion
}
Registering global shell hook:
public enum ShellEvents
{
HSHELL_WINDOWCREATED = 1,
HSHELL_WINDOWDESTROYED = 2,
HSHELL_ACTIVATESHELLWINDOW = 3,
HSHELL_WINDOWACTIVATED = 4,
HSHELL_GETMINRECT = 5,
HSHELL_REDRAW = 6,
HSHELL_TASKMAN = 7,
HSHELL_LANGUAGE = 8,
HSHELL_ACCESSIBILITYSTATE = 11
}
public class ShellHook
{
#region Events
private delegate IntPtr ShellProc(int nCode, IntPtr wParam, IntPtr lParam);
public delegate void HookEventHandler(object sender, ShellHookEventArgs e);
public event HookEventHandler WindowActivated;
#endregion
#region Constants
private const int WH_SHELL = 10;
private ShellProc _proc = null;
private static IntPtr _hookID = IntPtr.Zero;
#endregion
#region Imports
[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
private static extern IntPtr SetWindowsHookEx(int idHook,
ShellProc lpfn, IntPtr hMod, uint dwThreadId);
[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
[return: MarshalAs(UnmanagedType.Bool)]
private static extern bool UnhookWindowsHookEx(IntPtr hhk);
[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
private static extern IntPtr CallNextHookEx(IntPtr hhk, int nCode,
IntPtr wParam, IntPtr lParam);
[DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)]
private static extern IntPtr GetModuleHandle(string lpModuleName);
[DllImport("user32.dll")]
static extern int GetWindowText(IntPtr hWnd, StringBuilder text, int count);
#endregion
#region Fields
#endregion
#region Constructor
public ShellHook()
{
_proc = new ShellProc(HookCallback);
_hookID = SetHook(_proc);
}
#endregion
#region Methods
private IntPtr SetHook(ShellProc proc)
{
using (Process curProcess = Process.GetCurrentProcess())
using (ProcessModule curModule = curProcess.MainModule)
{
return SetWindowsHookEx(WH_SHELL, proc,
GetModuleHandle(curModule.ModuleName), 0);
}
}
private IntPtr HookCallback(int nCode, IntPtr wParam, IntPtr lParam)
{
if (nCode >= 0 && wParam.Equals(ShellEvents.HSHELL_WINDOWACTIVATED))
{
string windowTitle = GetWindowTitle(wParam);
if (this.WindowActivated != null)
this.WindowActivated(this, new ShellHookEventArgs(windowTitle));
}
return CallNextHookEx(_hookID, nCode, wParam, lParam);
}
private string GetWindowTitle(IntPtr hWnd)
{
const int nChars = 256;
StringBuilder Buff = new StringBuilder(nChars);
if (GetWindowText(hWnd, Buff, nChars) > 0)
{
return Buff.ToString();
}
return null;
}
#endregion
#region Destructor
public void Dispose()
{
UnhookWindowsHookEx(_hookID);
}
#endregion
}
For some reason, the keyboard hook works, but the shell hook fails (SetWindowsHookEx returns 0 and the callback is never reached).
Any ideas why?
I think I'll answer my own question. This quote from pinvoke.net explains why...
However, you cannot implement global hooks in Microsoft .NET Framework
except low level hooks. To install a global hook, a hook must have a
native dynamic-link library (DLL) export to inject itself in another
process that requires a valid, consistent function to call into. This
requires a DLL export, which .NET Framework does not support. Managed
code has no concept of a consistent value for a function pointer
because these function pointers are proxies that are built
dynamically.

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