I’m trying to disable popped contextmenu of ThemedWindow of devexpress when I click titlebar using mouserightbutton.
I used below code and it works in 'Window', but 'ThemedWindow' isn't working:
public MainWindow()
{
InitializeComponent();
Loaded += MainWindow_Loaded;
}
private void MainWindow_Loaded(object sender, RoutedEventArgs e)
{
IntPtr windowHandle = new WindowInteropHelper(this).Handle;
HwndSource hwndSource = HwndSource.FromHwnd(windowHandle);
hwndSource.AddHook(new HwndSourceHook(WndProc));
}
private IntPtr WndProc(IntPtr hwnd, int msg, IntPtr wParam, IntPtr lParam, ref bool handled)
{
if (msg == 0xa4)
{
handled = true;
}
return IntPtr.Zero;
}
If I want to do same thing in ThemedWindow, what should I do?
I found the solution in below url:
https://supportcenter.devexpress.com/ticket/details/t728500/themedwindow-doesn-t-have-the-allowsystemmenu-property
I am trying to create a C# application that will react on a global hotkey; ALT+H and then when I release the ALT key. This actually does work very well but my problem is that when my application has done whatever it should do with the hotkey then it should stop this hotkey from being processed by other applications. I got most of my code below from this StackOverflow post, Global keyboard capture in C# application, but I have seen somewhere else that return (IntPtr)1; should be able to stop further processing of the key.
But... when I am in e.g. Word or Wordpad and I press ALT+H then Word shows all kind of menus - I don't want it to as I only want my application to do something :-)
I am sorry for this rather long code but I assume it is important so you can get the full overview. There is only 1 place where I use return (IntPtr)1;.
My code:
using System;
using System.Diagnostics;
using System.Runtime.InteropServices;
using System.Windows.Forms;
using System.Windows.Input;
namespace MyNewProgram
{
static class Program
{
// Enable hotkeys
// https://stackoverflow.com/a/604417/2028935
private const int WH_KEYBOARD_LL = 13;
private const int WM_KEYDOWN = 0x0100;
private const int WM_KEYUP = 0x0101;
private const int WM_SYSKEYUP = 0x0105;
private const int VK_SHIFT = 0x10;
private const int VK_MENU = 0x12;
private static LowLevelKeyboardProc _proc = HookCallback;
private static IntPtr _hookID = IntPtr.Zero;
// Other variables
public static bool isAltPressedInThisApp = false;
private static MainWindow MyMainWindow;
// --------------------------------------------------------------------------------------
[STAThread] // STAThreadAttribute indicates that the COM threading model for the application is single-threaded apartment, https://stackoverflow.com/a/1361048/2028935
static void Main()
{
// Hook application to keyboard
_hookID = SetHook(_proc);
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
MyMainWindow = new MainWindow();
Application.Run(MyMainWindow);
// Unhook application from keyboard
UnhookWindowsHookEx(_hookID);
}
// --------------------------------------------------------------------------------------
// Required functions for globally hooking the keyboard
[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
public static extern short GetKeyState(int keyCode);
[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);
// --------------------------------------------------------------------------------------
// Hook the keyboard - action
private static IntPtr HookCallback(int nCode, IntPtr wParam, IntPtr lParam)
{
// React on KEYDOWN
if (nCode >= 0 && ((wParam == (IntPtr)WM_KEYDOWN) || (wParam == (IntPtr)WM_SYSKEYUP)))
{
int vkCode = Marshal.ReadInt32(lParam);
// H
if ((Keys)vkCode == Keys.H)
{
isAltPressedInThisApp = true;
// Is ALT pressed down
if ((GetKeyState(VK_MENU) & 0x8000) != 0)
{
Console.WriteLine("ALT + H");
return (IntPtr)1; // do not allow others to hook this key combo
}
}
}
// React on KEYUP
if (nCode >= 0 && wParam == (IntPtr)WM_KEYUP)
{
int vkCode = Marshal.ReadInt32(lParam);
// Is ALT not pressed down
if ((Keys)vkCode == Keys.LMenu)
{
Console.WriteLine("ALT UP");
}
}
return CallNextHookEx(_hookID, nCode, wParam, lParam);
}
// --------------------------------------------------------------------------------------
// Hook the keyboard
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);
}
}
}
}
I am not a solid C# developer as I am taking my first few babysteps here - so why would I throw myself in the deep waters of global hotkeys as one of the first things ;-) Is there anyone that can give some hints here as I probably have a silly mistake somewhere?
The idea behind, whenever the alt key pressed, it starts to swallow keys into one local list. if the pattern we need to see has been seen, it won't send, but for the every other pattern, it starts to send the keys again in the order it receives.
the code for examination phase:
enum WM
{
WM_KEYDOWN = 0x0100,
WM_KEYUP = 0x0101,
WM_SYSKEYUP = 0x0105,
WM_SYSKEYDOWN = 0x0104,
}
private static IntPtr HookCallback(int nCode, IntPtr wParam, IntPtr lParam)
{
if (nCode < 0)
return CallNextHookEx(_hookID, nCode, wParam, lParam);
KBDLLHOOKSTRUCT kbd = (KBDLLHOOKSTRUCT)Marshal.PtrToStructure(lParam, typeof(KBDLLHOOKSTRUCT));
Enum.TryParse<Keys>($"{kbd.vkCode}", out Keys key);
Enum.TryParse<WM>($"{wParam}", out WM message);
Console.WriteLine($"{message}:{key}");
return CallNextHookEx(_hookID, nCode, wParam, lParam);
}
when pressing alt+h and releasing, output:
WM_SYSKEYDOWN:LMenu
WM_SYSKEYDOWN:H
WM_SYSKEYUP:H
WM_KEYUP:LMenu
as you can see, windows sent both alt and h key. the code you provided only catch H key, so the window which receives keyboard messages think that alt pressed.
no one can fetch and filter out previously pressed key, so we need to catch alt key whenever we see it is pressed. if the next key not H, we should send the keys we have fetched in the order we received.
i have written the below code to handle the situation, but i can not be pretty sure how it works on the real windows machine cause i have an osx operating system just because of that i am running windows in the virtual machine which is also change key strokes when i'm pressing.
if it's still not enough, you can wait and i may be able to try and figure it out at my office in the real windows machine. but i think you get the idea and work it out on your own.
[StructLayout(LayoutKind.Sequential)]
public class KBDLLHOOKSTRUCT
{
public uint vkCode;
public uint scanCode;
public KBDLLHOOKSTRUCTFlags flags;
public uint time;
public UIntPtr dwExtraInfo;
}
[Flags]
public enum KBDLLHOOKSTRUCTFlags : uint
{
LLKHF_EXTENDED = 0x01,
LLKHF_INJECTED = 0x10,
LLKHF_ALTDOWN = 0x20,
LLKHF_UP = 0x80,
}
[DllImport("user32.dll")]
static extern void keybd_event(byte bVk, byte bScan, uint dwFlags, UIntPtr dwExtraInfo);
enum WM
{
WM_KEYDOWN = 0x0100,
WM_KEYUP = 0x0101,
WM_SYSKEYUP = 0x0105,
WM_SYSKEYDOWN = 0x0104,
}
private static void ReSendKeys(int index = -1)
{
_index = -1;
var copiedKeys = _swallowedKeys.ToArray();
for (int i = 0; i < copiedKeys.Length; ++i)
{
bool up = copiedKeys[i].Item1 == (IntPtr)WM.WM_SYSKEYUP || copiedKeys[i].Item1 == (IntPtr)WM.WM_KEYUP;
keybd_event((byte)copiedKeys[i].Item2.vkCode, (byte)copiedKeys[i].Item2.scanCode, up ? 2u : 0u, UIntPtr.Zero);
}
_index = index;
_swallowedKeys.Clear();
}
private static List<Tuple<IntPtr, KBDLLHOOKSTRUCT>> _swallowedKeys = new List<Tuple<IntPtr, KBDLLHOOKSTRUCT>>();
private static int _index = 0;
private static IntPtr HookCallback(int nCode, IntPtr wParam, IntPtr lParam)
{
if (nCode < 0)
return CallNextHookEx(_hookID, nCode, wParam, lParam);
KBDLLHOOKSTRUCT kbd = (KBDLLHOOKSTRUCT)Marshal.PtrToStructure(lParam, typeof(KBDLLHOOKSTRUCT));
Enum.TryParse<Keys>($"{kbd.vkCode}", out Keys key);
Enum.TryParse<WM>($"{wParam}", out WM message);
Console.Write($"{message}:{key}");
// we know that when _index is -1, ReSendKeys function has been called
// so do not filter out first alt key
if (_index == -1)
{
_index++;
Console.WriteLine();
return CallNextHookEx(_hookID, nCode, wParam, lParam);
}
// we are at the beginning of the sequence we will catch
// if it's alt key filter it out, and increment the variable
if (_index == 0)
{
_swallowedKeys.Add(new Tuple<IntPtr, KBDLLHOOKSTRUCT>(wParam, kbd));
if (message == WM.WM_SYSKEYDOWN && key == Keys.LMenu)
{
_index++;
Console.WriteLine(" filtered out");
return (IntPtr)1;
}
else
{
_swallowedKeys.Clear();
// do nothing
}
}
if (_index == 1)
{
_swallowedKeys.Add(new Tuple<IntPtr, KBDLLHOOKSTRUCT>(wParam, kbd));
// if the next key is H, then filter it out also
if (message == WM.WM_SYSKEYDOWN && key == Keys.H)
{
_index++;
_swallowedKeys.RemoveAt(_swallowedKeys.Count - 1);
Console.WriteLine(" filtered out");
return (IntPtr)1;
}
// if not, we filtered out wrong sequence, we need to resend them
else
{
Console.WriteLine();
ReSendKeys();
return (IntPtr)1;
}
}
if (_index == 2)
{
_swallowedKeys.Add(new Tuple<IntPtr, KBDLLHOOKSTRUCT>(wParam, kbd));
if (message == WM.WM_SYSKEYUP && key == Keys.H)
{
_index++;
_swallowedKeys.RemoveAt(_swallowedKeys.Count - 1);
Console.WriteLine(" filtered out");
return (IntPtr)1;
}
else
{
// if user pressed H but not released and pressed another key at the same time
// i will pass that situation, if u need to handle something like that, you got the idea, please fill that block of code
}
}
if (_index == 3)
{
_swallowedKeys.Add(new Tuple<IntPtr, KBDLLHOOKSTRUCT>(wParam, kbd));
if (message == WM.WM_KEYUP && key == Keys.LMenu)
{
_index = 0;
_swallowedKeys.Clear();
Console.WriteLine(" filtered out");
Console.WriteLine("shortcut disabled");
return (IntPtr)1;
}
else
{
Console.WriteLine();
// user has been pressed Alt + H, H released but not alt, so we can expect one H again, but we need to send this pressed key with Alt prefixed
ReSendKeys(1);
return (IntPtr)1;
}
}
Console.WriteLine();
return CallNextHookEx(_hookID, nCode, wParam, lParam);
}
I'm looking to detect and handle keycodes from a USB HID keyboard that fall outside the "normal" set of codes, i.e. codes above 100 (0x64) in a .NET Windows Forms application (.NET Framework 4.5).
Specifically, in my case I need to detect codes between 0x68 and 0x78, but I'd like to be able to detect anything up to 0xA4, which seems to be the upper limit of HID keyboard codes (aside from things like Ctrl, Alt, Win, etc.)
This question here seemed to be exactly what I was looking for, but I have had no success getting the advice on that answer to work. I have KeyPreview set to true for the form, and event handlers registered for KeyDown, KeyPress, and PreviewKeyDown, but none of them fire on reception of an 0x68 (F13) code. For now I'd just like to print the pressed key to a richtextbox control:
public mainFrm()
{
InitializeComponent();
this.KeyPreview = true;
this.KeyDown += new KeyEventHandler(KeyDownHandler);
this.KeyPress += new KeyPressEventHandler(KeyPressHandler);
this.PreviewKeyDown += new PreviewKeyDownEventHandler(PreviewKeyHandler);
}
private void KeyPressHandler(object sender, KeyPressEventArgs e)
{
rtb_hidLog.AppendText("Press: " + e.KeyChar.ToString() + "\r\n");
}
private void KeyDownHandler(object sender, KeyEventArgs e)
{
rtb_hidLog.AppendText("KeyDown: "+ e.KeyCode.ToString() + "\r\n");
}
private void PreviewKeyHandler(object sender, PreviewKeyDownEventArgs e)
{
rtb_hidLog.AppendText("Preview: " + e.KeyCode.ToString() + "\r\n");
}
I even tried overriding ProcessCmdKey (as per this question) and that also does not fire on 0x68:
protected override bool ProcessCmdKey(ref Message msg, Keys keyData)
{
rtb_hidLog.AppendText("CmdKey: " + keyData.ToString() + "\r\n");
return base.ProcessCmdKey(ref msg, keyData);
}
I have a USB HID Keyboard device connected (a PSoC microcontroller as a HID keyboard) that sends the 0x68 (F13) keycode when I press a button, but it doesn't fire the PreviewKeyHander. A standard 'A' code (0x04) from the PSoC device fires the KeyDownHandler and KeyPressHandler events with no problem. I have confirmed via USB Analyzer that the 0x68 code is being sent correctly, I just can't seem to force .NET to recognize it and fire an event. Is there something I'm missing or a trick I need to do to force my application to fire an event on these codes?
I've now also tried using Interop to use the win32 API (User32.dll) to hook into the keyboard input, and that also does not work. I get the same results; the hooked event will fire for all the keys on my keyboard, but anything not in that range does not fire a key pressed event.
My USB HID descriptor for the keyboard device, in case there is some issue there:
You can use a keyboard interceptor "in a separate DLL project that is referenced in your application" that is used by Form like this:
public delegate IntPtr KeyBoardHook( int nCode, IntPtr wParam, IntPtr lParam);
public class InterceptKeys : IDisposable
{
private const int WH_KEYBOARD_LL = 13;
private const int WM_KEYDOWN = 0x0100;
private KeyBoardHook _proc;
public event KeyBoardHook OnKeyBoardKeyClicked;
private static IntPtr _hookID = IntPtr.Zero;
public InterceptKeys()
{
_proc = HookCallback;
_hookID = SetHook(_proc);
if(_hookID == IntPtr.Zero)
{
throw new Exception($"Error Happened [{Marshal.GetLastWin32Error()}]");
}
}
public void Dispose()
{
UnhookWindowsHookEx(_hookID);
}
private IntPtr SetHook(KeyBoardHook 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)
{
OnKeyBoardKeyClicked?.Invoke(nCode, wParam, lParam);
//if (nCode >= 0 && wParam == (IntPtr)WM_KEYDOWN)
//{
// int vkCode = Marshal.ReadInt32(lParam);
// Console.WriteLine((char)vkCode);
//}
return CallNextHookEx(_hookID, nCode, wParam, lParam);
}
[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
private static extern IntPtr SetWindowsHookEx(int idHook,
KeyBoardHook 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("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)]
private static extern IntPtr GetModuleHandle(string lpModuleName);
}
i was trying to override this WndProc in my win form application but got error IntPtr WndProc no suitable method found to override. my code as follows
protected override IntPtr WndProc(IntPtr hwnd, int msg, IntPtr wParam, IntPtr lParam, ref bool handled)
{
if (msg == NativeCalls.APIAttach && (uint)lParam == NativeCalls.SKYPECONTROLAPI_ATTACH_SUCCESS)
{
// Get the current handle to the Skype window
NativeCalls.HWND_BROADCAST = wParam;
handled = true;
return new IntPtr(1);
}
// Skype sends our program messages using WM_COPYDATA. the data is in lParam
if (msg == NativeCalls.WM_COPYDATA && wParam == NativeCalls.HWND_BROADCAST)
{
COPYDATASTRUCT data = (COPYDATASTRUCT)Marshal.PtrToStructure(lParam, typeof(COPYDATASTRUCT));
StatusTextBox.Items.Add(data.lpData + Environment.NewLine);
// Check for connection
//if (data.lpData.IndexOf("CONNSTATUS ONLINE") > -1)
// ConnectButton.IsEnabled = false;
// Check for calls
IsCallInProgress(data.lpData);
handled = true;
return new IntPtr(1);
}
return IntPtr.Zero;
}
anyone can guide me what i am missing. thanks
Your method signature is incorrect, Form.WndProc you are overriding returns void.
protected virtual void WndProc(ref Message m)
I don't know where you got that code, port from C++ maybe? but it won't work with a WinForms form.
In WinForms I used the following block of code to stop the application gaining focus by being clicked on:
private const int WM_MOUSEACTIVATE = 0x0021;
private const int MA_NOACTIVATEANDEAT = 0x0004;
protected override void WndProc(ref Message m)
{
if (m.Msg == WM_MOUSEACTIVATE)
{
m.Result = (IntPtr)MA_NOACTIVATEANDEAT;
return;
}
base.WndProc(ref m);
}
Is there any alternative to this in a WPF application? Can I use a HwndSource? Here is what I have so far (WM_MOUSEACTIVATE alone does not work as required and the application still gets focus):
protected override void OnSourceInitialized(EventArgs e)
{
base.OnSourceInitialized(e);
HwndSource source = PresentationSource.FromVisual(this) as HwndSource;
source.AddHook(WndProc);
}
private IntPtr WndProc(IntPtr hwnd, int msg, IntPtr wParam, IntPtr lParam, ref bool handled)
{
// Handle messages...
int WM_MOUSEACTIVATE = 0x0021;
int WM_LBUTTONDOWN = 0x0201; //513
int WM_LBUTTONUP = 0x0202; //514
int WM_LBUTTONDBLCLK = 0x0203; //515
if (msg == WM_MOUSEACTIVATE || msg == MA_NOACTIVATEANDEAT || msg == WM_LBUTTONDOWN || msg == WM_LBUTTONUP || msg == WM_LBUTTONDBLCLK)
{
handled = true;
}
return IntPtr.Zero;
}
How can I get the Message Result?
Resolved by using:
private IntPtr WndProc(IntPtr hwnd, int msg, IntPtr wParam, IntPtr lParam, ref bool handled)
{
// Handle messages...
int WM_MOUSEACTIVATE = 0x0021;
if (msg == WM_MOUSEACTIVATE )
{
handled = true;
return new IntPtr(MA_NOACTIVATEANDEAT);
}
return IntPtr.Zero;
}