Question

我想制作一个带有图标拼贴的Swing程序，当你点击它们时会播放某些声音。为此，我创建了这个类：

public class Item extends JLabel implements MouseListener {
    public Item(String s) {
           // constructor setting background icon and private field with the sound to play
    }

   public void playSound(); //plays the sound

    @Override
    public void mouseClicked(MouseEvent e) {
        System.out.println("Clicked");
        this.playSound();

    }


    @Override
    public void mouseEntered(MouseEvent e) {
        // TODO Auto-generated method stub

    }


    @Override
    public void mouseExited(MouseEvent e) {
        // TODO Auto-generated method stub

    }


    @Override
    public void mousePressed(MouseEvent e) {
        // TODO Auto-generated method stub
        System.out.println("Pressed");

    }


    @Override
    public void mouseReleased(MouseEvent e) {
        // TODO Auto-generated method stub

    }
}

然后我创建了一个自定义JFrame类：

public class Frame extends JFrame {
    /**
     * 
     */
    private static final long serialVersionUID = 9221468315661092752L;
    public static final int DEFAULT_FRAME_WIDTH=400;
    public static final int DEFAULT_FRAME_HEIGHT=400;
    private GridLayout gridLayout;

    private ArrayList<Item> tiles=new ArrayList<Item>();


    public Frame() {
        super("Title");
        setDefaultCloseOperation(EXIT_ON_CLOSE);
        setSize(new Dimension(DEFAULT_FRAME_WIDTH,DEFAULT_FRAME_HEIGHT));
        gridLayout=new GridLayout(4,4,10,10);
        setLayout(gridLayout);
        addItems();

    }

    public void addItems() {
        Item item=new Item("name");
        Item item2=new Item("name");
        tiles.add(item);
        tiles.add(item2);
        this.add(item);
        this.add(item2);
    }

    public static void main(String[] args) {

        Frame frame=new Frame();
        frame.setVisible(true);
    }

图块通常在网格布局中显示，但问题是鼠标监听器不起作用。我在println()和mouseClicked()放置的mousePressed()未被调用。

我可以尝试向MouseListener类添加Item，以便Item有一个MouseListener，但我想知道上面的代码有什么问题。< / p>

Answer 1

你有两个问题。一，你的JLabel没有显示（虽然我不确定是否故意遗漏）。二，你永远不会添加鼠标监听器。您可以通过向构造函数添加两个语句来完成此操作，而无需创建任何额外的类：

public Item(String s) {
   super(s); //initializes the text and display using JLabel's constructor
   addMouseListener(this); //uses the reference of this Item as a MouseListener
}

MouseListener不会触发自定义JLabel

1 个答案: