哪个鼠标键位于中间？

Question

我目前正在用Java开发程序，仅当用户同时用鼠标左键和右键单击时，才必须触发特定事件。

由于这有点不合常规，因此我决定首先进行测试。这里是：

import javax.swing.JFrame;
import javax.swing.JButton;
import javax.swing.JLabel;
import java.awt.event.MouseListener;
import java.awt.event.MouseEvent;

public class GUI
{
    private JFrame mainframe;
    private JButton thebutton;

    private boolean left_is_pressed;
    private boolean right_is_pressed;

    private JLabel notifier;

    public GUI ()
    {
        thebutton = new JButton ("Double Press Me");
        addListen ();
        thebutton.setBounds (20, 20, 150, 40);

        notifier = new JLabel (" ");
        notifier.setBounds (20, 100, 170, 20);

        mainframe = new JFrame ("Double Mouse Tester");
        mainframe.setDefaultCloseOperation (JFrame.DISPOSE_ON_CLOSE);
        mainframe.setResizable (false);
        mainframe.setSize (400, 250);

        mainframe.setLayout (null);

        mainframe.add (thebutton);
        mainframe.add (notifier);

        mainframe.setVisible (true);

        left_is_pressed = right_is_pressed = false;
    }

    private void addListen ()
    {
        thebutton.addMouseListener (new MouseListener ()
        {
            @Override public void mouseClicked (MouseEvent e) { }
            @Override public void mouseEntered (MouseEvent e) { }
            @Override public void mouseExited (MouseEvent e) { }

            @Override public void mousePressed (MouseEvent e)
            {
                //If left button pressed
                if (e.getButton () == MouseEvent.BUTTON1)
                {
                    //Set that it is pressed
                    left_is_pressed = true;

                    if (right_is_pressed)
                    {
                        //Write that both are pressed
                        notifier.setText ("Both pressed");
                    }

                }
                //If right button pressed
                else if (e.getButton () == MouseEvent.BUTTON3)
                {
                    //Set that it is pressed
                    right_is_pressed = true;

                    if (left_is_pressed)
                    {
                        //Write that both are pressed
                        notifier.setText ("Both pressed");
                    }
                }
            }

            @Override public void mouseReleased (MouseEvent e)
            {
                //If left button is released
                if (e.getButton () == MouseEvent.BUTTON1)
                {
                    //Set that it is not pressed
                    left_is_pressed = false;

                    //Remove notification
                    notifier.setText (" ");
                }
                //If right button is released
                else if (e.getButton () == MouseEvent.BUTTON3)
                {
                    //Set that it is not pressed
                    right_is_pressed = false;

                    //Remove notification
                    notifier.setText (" ");
                }
            }
        });
    }
}

我对其进行了测试，并且可以正常工作，但是存在问题。

如您所见，鼠标左键由表示，MouseEvent.BUTTON1鼠标右键由表示MouseEvent.BUTTON3。

如果用户的鼠标没有滚轮（显然仍然存在此类鼠标），则在MouseEvent中仅设置两个按钮。这是否意味着右键将由MouseEvent.BUTTON2代替MouseEvent.BUTTON3？如果是，如何更改代码以适应此要求？有什么办法可以检测到这种情况吗？

我阅读了在MouseListener界面和MouseEvent上可以找到的所有内容，但是却找不到任何相关信息。

Answer 1

要确定按下了哪个鼠标按钮，SwingUtilities的以下三种方法可以帮助您：

1. isLeftMouseButton
2. isMiddleMouseButton
3. isRightMouseButton