如何让鼠标输入仅在 Java 中按下鼠标时才执行

Question

我想执行鼠标只有在当前按下鼠标时才输入，基本上是这样的：

    @Override
    public void mouseEntered(MouseEvent e) {
       if(e.mouseDown()){
         //Do stuff
        }
    }

我可以这样做吗，还是需要鼠标运动侦听器还是什么？

谢谢！

编辑：抱歉应该更清楚地说明这一点，但是我需要按下鼠标 在它进入组件之前，就像按住鼠标并将鼠标悬停在组件上会激活侦听器

Answer 1

您可能希望评估 MouseEvent API 以查看哪些方法可用，因为我认为您会在那里找到您的解决方案：

  myComponent.addMouseListener(new MouseAdapter() {
     @Override
     public void mouseEntered(MouseEvent mEvt) {
        System.out.println("mouse entered");
        if (mEvt.getModifiers() == MouseEvent.BUTTON1_MASK) {
           System.out.println("Mouse dragging as entered");
        }
     }
  });

例如：

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class MouseEnteredPressed extends JPanel {
   private static final int SIDE = 500;
   public MouseEnteredPressed() {
      setLayout(new GridBagLayout());
      JLabel label = new JLabel("Hovercraft Rules The World!");
      label.setFont(label.getFont().deriveFont(Font.BOLD, 24));
      label.setBorder(BorderFactory.createLineBorder(Color.LIGHT_GRAY));
      add(label);
      label.addMouseListener(new MouseAdapter() {
         @Override
         public void mouseEntered(MouseEvent mEvt) {
            System.out.println("mouse entered");
            if (mEvt.getModifiers() == MouseEvent.BUTTON1_MASK) {
               System.out.println("Mouse dragging as entered");
            }
         }
      });
   }
   @Override
   public Dimension getPreferredSize() {
      return new Dimension(SIDE, SIDE);
   }
   private static void createAndShowGui() {
      MouseEnteredPressed mainPanel = new MouseEnteredPressed();
      JFrame frame = new JFrame("MouseEnteredPressed");
      frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      frame.getContentPane().add(mainPanel);
      frame.pack();
      frame.setLocationByPlatform(true);
      frame.setVisible(true);
   }
   public static void main(String[] args) {
      SwingUtilities.invokeLater(new Runnable() {
         public void run() {
            createAndShowGui();
         }
      });
   }
}