我制作的应用程序即使窗口没有焦点,也应该能够使用KeyListener进行键盘输入。我不知道如何使KeyListeners在不关注窗口的情况下工作,有人可以帮我吗?
您可以使用JNativeHook:https://github.com/kwhat/jnativehook
示例:
import org.jnativehook.GlobalScreen;
import org.jnativehook.NativeHookException;
import org.jnativehook.keyboard.NativeKeyEvent;
import org.jnativehook.keyboard.NativeKeyListener;
public class GlobalKeyListenerExample implements NativeKeyListener {
public void nativeKeyPressed(NativeKeyEvent e) {
System.out.println("Key Pressed: " + NativeKeyEvent.getKeyText(e.getKeyCode()));
if (e.getKeyCode() == NativeKeyEvent.VK_ESCAPE) {
GlobalScreen.unregisterNativeHook();
}
}
public void nativeKeyReleased(NativeKeyEvent e) {
System.out.println("Key Released: " + NativeKeyEvent.getKeyText(e.getKeyCode()));
}
public void nativeKeyTyped(NativeKeyEvent e) {
System.out.println("Key Typed: " + e.getKeyText(e.getKeyCode()));
}
public static void main(String[] args) {
try {
GlobalScreen.registerNativeHook();
}
catch (NativeHookException ex) {
System.err.println("There was a problem registering the native hook.");
System.err.println(ex.getMessage());
System.exit(1);
}
GlobalScreen.addNativeKeyListener(new GlobalKeyListenerExample());
}
}
当窗口未聚焦时,没有Java级别的方法可以处理事件。您需要使用OS函数和Java API(JNI)编写本机库。但是,如果它足以处理焦点窗口中的事件,则可以在框架的内容窗格上使用JComponent.registerKeyboardAction。