哪个鼠标键是中间的？

我目前正在开发一个Java程序，只有当用户点击左键和右键单击按钮时才能触发某个事件。

由于它有点不同寻常，我决定先测试一下。 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 (" "); } } }); } } 

我测试了它并且它可以工作，但是有一个问题。

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

如果用户有一个没有滚轮的鼠标（显然这样的鼠标仍然存在），那么在MouseEvent中只设置了两个按钮。 这是否意味着右键将由MouseEvent.BUTTON2而不是MouseEvent.BUTTON3 ？ 如果是，我如何更改我的代码以适应这个？ 有什么方法可以检测到这样的东西吗？

我在MouseListener接口和MouseEvent上读到了我能找到的任何东西，但是我找不到这个。

Answer 1

要确定按下哪个鼠标按钮， SwingUtilities中的这三个方法可以帮助您：

1. isLeftMouseButton
2. isMiddleMouseButton
3. isRightMouseButton

Answer 2

您可以使用SwingUtilties中的实用程序方法：

 SwingUtilities.isLeftMouseButton(MouseEvent anEvent) SwingUtilities.isRightMouseButton(MouseEvent anEvent) SwingUtilities.isMiddleMouseButton(MouseEvent anEvent) 

Answer 3

还有MouseEvent.isPopupTrigger() 。 如果按下鼠标右键，此方法应返回true。