How to use System-Wide Hotkeys in your Qt application

First of all, this method can only be used in Windows because it makes use of the RegisterHotKey function which is a Win32 API function. So if you want to trigger a function in your Qt application even when your application is out of focus or minimized or even hidden then follow the steps below one by one:

1. Include the required header files in your code.

#include "windows.h"

2. Add required libraries to your qmake project (.PRO file)

LIBS += -lUser32

3. Call RegisterHotKey function when your program starts. (Note that in this example I am trying to use ALT+CTRL+M as the global hotkey to be used by my program.)

if (!RegisterHotKey(HWND(winId()), 0, MOD_ALT | MOD_CONTROL, 0x4D))
	QMessageBox::warning(this, "Warning", "Can't register hotkey ALT+CTRL+M");

4. Override the nativeEvent function in your MainWindow app.
To do this first add the following code to your MainWindow class:

bool nativeEvent(const QByteArray &eventType, void *message, long *result);

And write the function body like this:

bool MainWindow::nativeEvent(const QByteArray& eventType, void* message, long* result)
	MSG* msg = static_cast<MSG*>(message);
	if (msg->message == WM_HOTKEY)
		QMessageBox::information(this, "OK", "Hotkey pressed!");
	return false;

For any questions that you might have please put a comment below.

5 Replies to “How to use System-Wide Hotkeys in your Qt application”

  1. I implemented this solution and it works fine, but now my menu bar isn’t working. I added qDebug() << *msg in the nativeEvent function and it seems like the nativeEvent receives all event calls but Qt doesn't get the events anymore. How can I fix this?

    1. I see. Can you try the following solution please:

      Replace the followig:
      return false;

      with this line:
      return QMainWindow::nativeEvent(eventType, message, result);

      Let me know if this helps.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.