java - 获取我的操作以查看我的其他对象

Question

我有一个 JLabel，上面有按键绑定(bind)操作。我已经为某些操作定义了一些代码，但是，唉，方法中还有其他 JLabels、JPanel 和其他东西(这是在 main() 中)，我希望我的操作能够愚弄它们。

我尝试将操作更改为接受参数，但没有成功，如何让我的操作接受参数进行操作？有什么办法吗？我已经查看过，但这非常具体，而且我没有看到几个好的例子。

这是我的代码的一个很好的部分:

    /*Bunch of stuff I want my actions to interact with above - another JLabel, a JPanel*/
    ImageIcon cursor = new ImageIcon("cursor.gif");
    JLabel cursorlbl = new JLabel("", cursor, JLabel.CENTER);
    Action goRight = new AbstractAction() {

        @Override
        public void actionPerformed(ActionEvent arg0) {
            System.out.println("lol");

        }
    };

    Action goLeft = new AbstractAction() {

        @Override
        public void actionPerformed(ActionEvent arg0) {
            System.out.println("lol2");
        }
    };

    Action goUp = new AbstractAction() {

        @Override
        public void actionPerformed(ActionEvent arg0) {


        }
    };

    Action goDown = new AbstractAction() {

        @Override
        public void actionPerformed(ActionEvent arg0) {
            System.out.println("lol2");

        }
    };


    cursorlbl.setFocusable(true);
    cursorlbl.getInputMap().put(KeyStroke.getKeyStroke("RIGHT"),
            "pressed right");
    cursorlbl.getInputMap().put(KeyStroke.getKeyStroke("LEFT"),
            "pressed left");
    cursorlbl.getActionMap().put("pressed right", goRight);
    cursorlbl.getActionMap().put("pressed left", goLeft);

Answer 1

您可以将每个操作声明为子类(无论如何，这都会开始分离 MVC)，并且您想要操作父类中的字段的每个项目。示例:

// Parent Class
public class ParentClass{
//Field you want to mess with in your action
   JLabel cursorlbl = new JLabel("");

    // Action that does things
    public class MoveAction extends AbstractAction{
        char direction;

        //Constructor for action
        public MoveAction(char direction){
            this.direction = direction;
        }

        @Override
        public void actionPerformed(ActionEvent arg0) {
            int change = 0;

            // Figure out how you'll be changing the variable
            if(direction == 'u' || direction == 'r'){
                change = 1;
            } else{
                change = -1;
            }

            // Apply the change to the correct variable
            if(direction == 'u' || direction =='d'){
                cursy += change;
            } else{
                cursx += change;
            }

            //Example how you can access the parent class's fields
            cursorlbl.setLocation(cursx, cursy);
        }       
    }
}

然后要设置您的操作，您只需创建子类的实例:

    contentArea.getActionMap().put("pressed right", new MoveAction('r'));
    contentArea.getActionMap().put("pressed left", new MoveAction('l'));