java - Java中检查鼠标是否被点击

Question

我正在用 Java 编写 GUI。我需要知道如何检查用户是否单击鼠标。我知道如何检查鼠标的位置，但我只需要检查它是否被单击。

import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
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import java.awt.*;
import java.awt.event.*;
import java.awt.image.*;
import java.io.*;

import javax.imageio.*;
import javax.swing.*;

/**
 * This class demonstrates how to load an Image from an external file
 */
public class LoadImageApp extends Component {

    BufferedImage img;

    public void paint(Graphics g) {
        g.drawImage(img, 50, 70, null);
    }

    public LoadImageApp() {
       try {
           img = ImageIO.read(new File("strawberry.jpg"));
       } catch (IOException e) {
       }

    }

    public Dimension getPreferredSize() {
        if (img == null) {
             return new Dimension(100,100);
        } else {
           return new Dimension(img.getWidth(null), img.getHeight(null));
       }
    }

    public static void main(String[] args) throws InterruptedException {

        JFrame f = new JFrame("Load Image Sample");

        f.addWindowListener(new WindowAdapter(){
                public void windowClosing(WindowEvent e) {
                    System.exit(0);
                }
            });

        f.add(new LoadImageApp());
        f.pack();
        f.setVisible(true);
        f.setResizable(true);
        while(true){
            Thread.sleep(1000);
            PointerInfo a = MouseInfo.getPointerInfo();
            Point b = a.getLocation();
            int x = (int) b.getX();
            int y = (int) b.getY();

            System.out.println(x);
            System.out.println(y);
        }
        }
    public void mouseClicked(MouseEvent e) {
        System.out.println("mouseClicked");  
        }
}

这是我的全部代码，所以请解释一下如何实现那个鼠标检查器的东西。谢谢!

Answer 1

实现 MouseListener 接口(interface)并将代码放入 mouseClicked(MouseEvent e) 方法中。然后将此类的实例添加为组件的监听器。

基本上，您创建一个这样的类:

class myMouseListener implements MouseListener {

    @Override
    public void mouseClicked(MouseEvent arg0) { 
       //Put the code you want here
       //...
       //...
     }

     @Override
     public void mouseEntered(MouseEvent arg0) { }

     @Override
     public void mouseExited(MouseEvent arg0) { }

     @Override
     public void mousePressed(MouseEvent arg0) { }

     @Override
     public void mouseReleased(MouseEvent arg0) { }

}

然后您只需使用 myMouseListener 创建这个新类的新实例

myMouseListener mml = new myMouseListener();

然后将其添加为组件的监听器。像这样的东西:

myPanel.addMouseListener(mml);

这里的所有信息:http://docs.oracle.com/javase/7/docs/api/java/awt/event/MouseListener.html