Question

目前我正在学习Java，而且我遇到了问题。

我试图抓住KeyEvent，但它不起作用。

也许你们其中一个人有解决方案？

package test;

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

public class SpielFenster extends JFrame implements KeyListener {
    int posX = 100;
    int posY = 100;
    SpielFenster(){
        this.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE ); 
        this.setSize( 400, 600 );
        this.setTitle( "Hindi Bones - Lost in Labyrinth" );

        this.setVisible( true );
    }
    public void paint(Graphics g) { 
        super.paint(g);
        g.setColor(Color.ORANGE);
        g.fillOval(posX, posY, 20, 20); 
    }

    public void keyPressed(KeyEvent e) {
        test("test");
    }

    public void keyReleased(KeyEvent e) { test("test");}
    public void keyTyped(KeyEvent e) { test("test");}
    public void test(String x){
        System.out.println(x);
    }

    public static void main(String[] args){
        SpielFenster fenster = new SpielFenster();
        fenster.test("yoo");

    }
}

提前致谢！：）

Answer 1

因为你没有在任何摇摆组件上注册听众：

    .rvm/rubies/ruby-2.2.1/lib/ruby/2.2.0/base64.rb:58:in `decode64'
    app/controllers/buy_tags_controller.rb:18:in `block in index'
    app/controllers/buy_tags_controller.rb:13:in `each'
    app/controllers/buy_tags_controller.rb:13:in `index'
    actionpack (4.2.1) lib/action_controller/metal/implicit_render.rb:4:in `send_action'
    actionpack (4.2.1) lib/abstract_controller/base.rb:198:in `process_action'
    actionpack (4.2.1) lib/action_controller/metal/rendering.rb:10:in `process_action'
    actionpack (4.2.1) lib/abstract_controller/callbacks.rb:20:in `block in process_action'
    activesupport (4.2.1) lib/active_support/callbacks.rb:117:in `call'

请参阅： How to Write a Key Listener

Answer 2

你忘了将keylistener添加到你拥有的任何JComponents中...... 你唯一拥有的是JFrame，所以在JFrame中，在构造函数中这样做： this.addKeyListener(this);

这里面是你的应用程序：

package alltests;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class SpielFenster extends JFrame implements KeyListener{
    int posX = 100;
    int posY = 100;

    SpielFenster(){
        this.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE ); 
        this.setSize( 400, 600 );
        this.setTitle( "Hindi Bones - Lost in Labyrinth" );
        this.addKeyListener(this);//here <<<<<
        this.setVisible( true );
    }
    public void paint(Graphics g) { 
        super.paint(g);
        g.setColor(Color.ORANGE);
        g.fillOval(posX, posY, 20, 20); 
    }

    public static void main(String[] args){
        SpielFenster fenster = new SpielFenster();
    }

    @Override
    public void keyPressed(KeyEvent e) {
        test("test");
    }

    @Override
    public void keyReleased(KeyEvent e) {
        test("test");           
    }

    @Override
    public void keyTyped(KeyEvent e) {
        test("test");           
    }
    public void test(String x){
        System.out.println(x);
    }
}

希望有所帮助

Java Key Eventlistener

2 个答案: