Global low level keyboard hook freezing in c# .net 3.5 - c#

i have a frustrating problem with registering global hook.
I am using this class in my windows application:
using System;
using System.Diagnostics;
using System.Runtime.InteropServices;
using System.Windows.Forms;
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 void Hook()
{
_hookID = SetHook(_proc);
}
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)
{
MessageBox.Show("Test");
}
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);
}
Here is Program.cs
namespace TestHooks
{
static class Program
{
/// <summary>
/// The main entry point for the application.
/// </summary>
[STAThread]
static void Main()
{
InterceptKeys.Hook();
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
Application.Run(new Form1());
}
}
}
Everything works (MessageBox pops up) but windows freezes for a moment and beeper beeps. The problem doesn't occur on Windows 7 just on Vista. Any suggestions please?

You cannot use MessageBox in your code. It blocks execution, the keyboard goes dead. Use Console.WriteLine() for example, output goes to the Visual Studio Output window.
Beware that this code won't work anymore on .NET 4.0, GetModuleHandle() will return NULL.

Related

global mouse hook in console application

I want to get acquainted with WinAPI in C#.
I need to write a global mouse hook in the console application. I found the code that does this job. But I have a console application, and I shouldn't use Application.Run () from Windows.Forms.
I need to forward messages about the coordinates of the mouse from winAPI directly to the console window without winForms. How can i do this?
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_MOUSEMOVE == (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);
}
Add system.windows.forms as a reference to your project.
using System.Windows.Forms;
It should be work then.

c# keyboard hook works for only 10 times then it stops (or is supressed)?

It is the classic low level keyboard hook that I have used several times before quite successfully but lately it does not work right. It reads the keyboard inputs for exactly 10 times (10 times from any of the keys defined in HookCallback function) and then it stops. It is like some security feature of the OS or some other program like maybe an anivirus is getting in the way and suppressing the keyboard hook after 10 times.
Has anyone else encountered this 10 times limit? What could be the problem, in your opinion? I am using Windows 7 64 Bit and avast free antivirus. The program is written in c# 2008.
Here is the relevant code from program.cs:
static class Program
{
private const int WH_KEYBOARD_LL = 13;
private const int WM_KEYDOWN = 0x0100;
private static LowLevelKeyboardProc _proc = HookCallback;
private static IntPtr _hookID = IntPtr.Zero;
[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);
private delegate IntPtr LowLevelKeyboardProc(int nCode, IntPtr wParam, IntPtr lParam);
/// <summary>
/// The main entry point for the application.
/// </summary>
[STAThread]
static void Main()
{
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
_hookID = SetHook(_proc);
Application.Run(new Form1());
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);
if ((Keys)vkCode == Keys.Delete)
{
Form1.staticmethod1();
}
else if ((Keys)vkCode == Keys.F8)
{
Form1.staticmethod2();
}
else if ((Keys)vkCode == Keys.F9)
{
Form1.staticmethod3();
}
}
return CallNextHookEx(_hookID, nCode, wParam, lParam);
}
Thanks in advance.

C# SetWindowsHookEx with DirectX

I'm about to write something like a screenshot programm. For now I used the PrintWindow function with the handle of the active window -> GetForgroundWindow and to start it I set a hook on the keyboard. When I capture normal windows on the desktop it's ok, besides there is no hardware accelerated effects, but in a game the hook doesn't seem to work. (I know, that the PrintWindow won't do anything here, I'm implementing a SlimDX class at the time) Is that some sort of a problem with the game-side modified message loop? And if yes, is there a way to make it work :D I would appreciate a C# way, cause I'm bad at programming UI with C++ ^^
I hope it is just some sort of bug...
Greetz Coldi
EDIT:
public class KeyboardHook
{
#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
const int WH_KEYBOARD_LL = 13;
const int WM_KEYDOWN = 0x0100;
static LowLevelKeyboardProc m_proc = HookCallback;
static IntPtr m_hookID = IntPtr.Zero;
static Screenshot m_screen;
public static void Hook(Screenshot screenshotManager)
{
m_screen = screenshotManager;
m_hookID = SetHook(m_proc);
}
public static void Unhook()
{
UnhookWindowsHookEx(m_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);
#if DEBUG
Debug.WriteLine(((System.Windows.Forms.Keys)vkCode).ToString());
#endif
if ((System.Windows.Forms.Keys)vkCode == m_screen.CaptureKey)
{
m_screen.CaptureSimple();
}
}
return CallNextHookEx(m_hookID, nCode, wParam, lParam);
}
}
So on desktop it works pretty fine, but when I start a DirectX application, the keyhook doesn't get any pressed key (HookCallback isn't handeled)

Get key from any process

Ive seen many solutions online but none does exactly what I want. What is the best/simplest way to get any keys pressed in a given process (not my console applicaton) while my application is running in background. I dont need the modifiers or anything.
If you don't particularly care which process the keys are being pressed in the easiest method would be to call GetAsyncKeyState. It's rather limited though as it does not hook the keyboard and requires you to call it continuously. The best approach in my opinion is to hook the keyboard.
Using SetWindowsHookEx you can actually explicitly specify the identifier of the thread with which the hook procedure is to be associated so you can hook keys for a specific process (see dwThreadId).
Here's a class that you can use (originally found on a Micrsoft blog but I cannot seem to find the authors name at the moment!)
public delegate IntPtr KeyboardProcess(int nCode, IntPtr wParam, IntPtr lParam);
public sealed class KeyboardHook
{
public static event EventHandler<KeyPressedEventArgs> KeyPressed;
private const int WH_KEYBOARD = 13;
private const int WM_KEYDOWN = 0x0100;
private static KeyboardProcess keyboardProc = HookCallback;
private static IntPtr hookID = IntPtr.Zero;
public static void CreateHook()
{
hookID = SetHook(keyboardProc);
}
public static void DisposeHook()
{
UnhookWindowsHookEx(hookID);
}
private static IntPtr SetHook(KeyboardProcess keyboardProc)
{
using (Process currentProcess = Process.GetCurrentProcess())
using (ProcessModule currentProcessModule = currentProcess.MainModule)
{
return SetWindowsHookEx(WH_KEYBOARD, keyboardProc, GetModuleHandle(currentProcessModule.ModuleName), 0);
}
}
private static IntPtr HookCallback(int nCode, IntPtr wParam, IntPtr lParam)
{
if (nCode >= 0 && wParam == (IntPtr)WM_KEYDOWN)
{
int vkCode = Marshal.ReadInt32(lParam);
if (KeyPressed != null)
KeyPressed(null, new KeyPressedEventArgs((Keys)vkCode));
}
return CallNextHookEx(hookID, nCode, wParam, lParam);
}
[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
private static extern IntPtr SetWindowsHookEx(int idHook, KeyboardProcess lpfn, IntPtr hMod, uint dwThreadId);
[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", CharSet = CharSet.Auto, SetLastError = true)]
[return: MarshalAs(UnmanagedType.Bool)]
private static extern bool UnhookWindowsHookEx(IntPtr hhk);
}
public class KeyPressedEventArgs : EventArgs
{
public Keys KeyCode { get; set; }
public KeyPressedEventArgs(Keys Key)
{
KeyCode = Key;
}
}
Implementation via Console Application:
class Program
{
static void Main(string[] args)
{
KeyboardHook.CreateHook();
KeyboardHook.KeyPressed += KeyboardHook_KeyPressed;
Application.Run();
KeyboardHook.DisposeHook();
}
static void KeyboardHook_KeyPressed(object sender, KeyPressedEventArgs e)
{
Console.WriteLine(e.KeyCode.ToString());
}
}
What you're looking for is called a global keyboard hook. You can find more information and examples on MSDN.
Oh, so you're looking for "Autofire" in old-school gaming terms?
Instead of writing your own keyboard hook app (unless you're doing it for fun/the thrill of it/the exercise) you might want to look at AutoIt or AutoHotkey, which are both pretty good for keyboard/mouse automation.
See this thread for instance... http://www.autohotkey.com/board/topic/40598-autofire-keyboard/
I have found a way to hook only for a process.
You may need it.
int ProcessId = GetProcessesByName("Your_app_here").FirstOrDefault().Id;
private IntPtr SetHook(KeyboardHookHandler proc)
{
return SetWindowsHookEx(13, proc, GetModuleHandle(Process.GetProcessById(ProcessId).MainModule.ModuleName), GetWindowThreadProcessId(GetModuleHandle(Process.GetProcessById(ProcessId).MainModule.ModuleName), out int MainThreadId));
}
Remember to import these methods.
[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
private static extern IntPtr SetWindowsHookEx(int idHook, KeyboardHookHandler lpfn, IntPtr hMod, uint dwThreadId);
[DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)]
private static extern IntPtr GetModuleHandle(string lpModuleName);
[DllImport("user32.dll", SetLastError = true)]
static extern uint GetWindowThreadProcessId(IntPtr hWnd, out int lpdwProcessId);

Setting up mouse hook without removing currently running application?

I have a program that opens a GUI when run. I would then like to set up a mousehook using dllimports, but in order for it to work, I must call a new Application.Run() in this same class. Unfortunately though, this removes the original GUI. Is there any way I can run the mousehook on the original messageloop? I'm a bit lost here.
Here are a few key portions of the code:
//main
public static GUI GUIref;
static void Main()
{
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
Application.Run(GUIref = new GUI());
}
.
//Initializing constructor
public partial class GUI : Form
{
public GUI()
{
InitializeComponent();
keyReceive kR = new keyReceive();
mouseReceive mR = new mouseReceive();
}
}
.
//mousehook class:
public class mouseReceive : Form
{
private static LowLevelMouseProc _proc = HookCallback;
private static IntPtr _hookID = IntPtr.Zero;
public mouseReceive()
{
_hookID = SetHook(_proc);
//***This is where I have been putting Application.Run() to make the mousehook work***
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)
{
MessageBox.Show("");
}
return CallNextHookEx(_hookID, nCode, wParam, lParam);
}
private const int WH_MOUSE_LL = 14;
private enum MouseMessages
{
WM_LBUTTONDOWN = 0x0201
}
[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 the mouseReceive constructor, you are setting the hook and then immediately unhooking it. If you insert the Application.Run() where your comment is, that blocks the thread until the new window closes, thus the hook is not unhooked and works. The real fix would be to remove UnhookWindowsHookEx(_hookID) from the constructor and put it into a IDisposable pattern.
Side note: You also might have problems if you try to instantiate more than one instance of your mouseReceive class as it has static members for _proc and _hookID.

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