Java：如何在单击按钮时设置值？

Question

我需要编写一个按钮，在点击它时设置值。如何写一个actionPerformed方法来实现呢？

int a = 0;

void setValue(){
  a = 5;
}

public void actionPerformed(ActionEvent e) {
  /*when*/ e.getActionCommand() /*call setValue()*/
}

Answer 1

创建一个按钮，然后像这样添加ActionListener

private static JButton btn;
private statin int a;
btn = new JButton();
int a = 0;
btn.addActionListener(new ActionListener() {

@Override
public void actionPerformed(ActionEvent arg0) {
    a = 15;
    }
}

Answer 2

  JButton button = new JButton(" >> JavaProgrammingForums.com <<");
        //Add action listener to button
        button.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e)
            {
                a = 5 ;
                System.out.println("You clicked the button");
            }
        });