- 1 year ago
How to intercept keystrokes using Dart on Windows?
To intercept keystrokes using Dart on Windows, you can use the dart:ffi
library to call the Win32 API functions for low-level keyboard hooks. Here's an example of how you can intercept keystrokes using Dart on Windows:
Create a new Dart project: Create a new Dart project and add the
ffi
dependency to yourpubspec.yaml
file.Import the required libraries: Import the required libraries for
ffi
and Win32 API functions. You'll need thedart:ffi
,dart:io
, anddart:typed_data
libraries.arduinoimport 'dart:ffi';
import 'dart:io';
import 'dart:typed_data';
Define the Win32 API functions: Define the Win32 API functions that you'll use to set up and handle the low-level keyboard hook.
javatypedef LowLevelKeyboardProc = IntPtr Function(int nCode, IntPtr wParam, IntPtr lParam);
final user32 = DynamicLibrary.open('user32.dll');
final SetWindowsHookEx = user32.lookupFunction<
IntPtr Function(Uint32 idHook, Pointer<NativeFunction<LowLevelKeyboardProc>> lpfn, IntPtr hMod, Uint32 dwThreadId),
int Function(int idHook, Pointer<NativeFunction<LowLevelKeyboardProc>> lpfn, int hMod, int dwThreadId)
>('SetWindowsHookExW');
final UnhookWindowsHookEx = user32.lookupFunction<
Int32 Function(IntPtr hhk),
int Function(int hhk)
>('UnhookWindowsHookEx');
final CallNextHookEx = user32.lookupFunction<
IntPtr Function(IntPtr hhk, int nCode, IntPtr wParam, IntPtr lParam),
int Function(int hhk, int nCode, int wParam, int lParam)
>('CallNextHookEx');
final GetModuleHandle = user32.lookupFunction<
IntPtr Function(Pointer<Utf16> lpModuleName),
int Function(Pointer<Utf16> lpModuleName)
>('GetModuleHandleW');
Define the keyboard hook callback function: Define the callback function that will handle the keyboard hook events. This function will be called whenever a key is pressed or released.
scssfinal keyboardHook = Pointer.fromFunction<LowLevelKeyboardProc>((nCode, wParam, lParam) {
if (nCode >= 0) {
// Handle the keyboard event here
// wParam: 0x0100 for key down, 0x0101 for key up
// lParam: contains information about the key event
}
// Pass the event to the next hook in the chain
return CallNextHookEx(IntPtr.zero, nCode, wParam, lParam);
});
Set up the keyboard hook: Set up the low-level keyboard hook by calling the
SetWindowsHookEx
function with theWH_KEYBOARD_LL
hook ID.scssfinal hMod = GetModuleHandle(Utf16.toUtf16(''));
final hhk = SetWindowsHookEx(13, keyboardHook, hMod, 0);
Start the event loop: Start the Dart event loop to listen for keyboard events. You can use the
stdin.readLineSync()
function to pause the event loop and wait for user input to stop the hook.scss// Start the Dart event loop
stdin.readLineSync();
// Stop the keyboard hook
UnhookWindowsHookEx(hhk);
By following these steps, you should be able to intercept keystrokes using Dart on Windows. Keep in mind that low-level keyboard hooks can have significant performance and security implications, so use them with caution and only when