我有一个非常简单的 KeyEvent:
@Override
public void start(Stage stage) throws Exception {
Group root = new Group();
Scene scene = new Scene(root);
Canvas canvas = new Canvas( 900, 700 );
scene.setOnKeyPressed(new EventHandler<KeyEvent>() {
@Override
public void handle(KeyEvent ke) {
switch (ke.getCode()) {
case UP:
System.out.println("UP");
break;
case DOWN:
System.out.println("DOWN");
break;
case LEFT:
System.out.println("LEFT");
break;
case RIGHT:
System.out.println("RIGHT");
break;
case ENTER:
//ke.consume();
break;
default:
break;
}
}});
我想要达到的目标: 我开始运行程序,如果我按上、下、左、右,输出会写回给我上、下、左、右(这是正确的,没有问题)。 但!如果我按 Enter,如果我按上、下、左、右、Enter 或其他键,则不会写回输出 UP、DOWN、LEFT、RIGHT。
所以我喜欢在按下 ENTER 按钮时停止 KeyEvent“运行”。
最佳答案
你有几个机会,我首先想到的是这两个。
1) 将关键事件的监听器存储为类的成员,然后按 ENTER 键取消注册。
private EventHandler<KeyEvent> keyHandler;
@Override
public void start(Stage stage) {
final Scene scene = new Scene(new Group());
stage.setTitle("Table View Sample");
stage.setWidth(450);
stage.setHeight(500);
keyHandler = new EventHandler<KeyEvent>() {
@Override
public void handle(KeyEvent ke) {
switch (ke.getCode()) {
case ENTER:
scene.removeEventHandler(KeyEvent.KEY_PRESSED, keyHandler);
break;
case UP:
System.out.println("UP");
break;
case DOWN:
System.out.println("DOWN");
break;
case LEFT:
System.out.println("LEFT");
break;
case RIGHT:
System.out.println("RIGHT");
break;
default:
break;
}
}};
scane.addEventHandler(KeyEvent.KEY_PRESSED, keyHandler);
2) 按 ENTER 键时,将 boolean 值存储到成员,如果设置了该成员,则使用该事件。
private Boolean enterPressed = false;
@Override
public void start(Stage stage) {
final Scene scene = new Scene(new Group());
stage.setTitle("Table View Sample");
stage.setWidth(450);
stage.setHeight(500);
scene.setOnKeyPressed(new EventHandler<KeyEvent>() {
@Override
public void handle(KeyEvent ke) {
if(enterPressed){
ke.consume();
return;
}
switch (ke.getCode()) {
case ENTER:
enterPressed = true;
break;
case UP:
System.out.println("UP");
break;
case DOWN:
System.out.println("DOWN");
break;
case LEFT:
System.out.println("LEFT");
break;
case RIGHT:
System.out.println("RIGHT");
break;
default:
break;
}
}});
两者都有效,选择你喜欢的。
关于java - KeyEvent停止监听JavaFX,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/37235840/