JButton的动作侦听器无法正常工作 [英] Action Listener for JButton isn't working

问题描述

我正在尝试自己学习Java，并且正在寻找一个安全的文本编辑器，您必须登录该文本编辑器才能访问该文本。但是，动作侦听器无法使用任何按钮，而且我也无法弄清楚出了什么问题。

I'm trying to learn java by myself, and am looking to make a secure text editor that you have to log into to access the text. However, the action listener isn't working for any of the buttons, and i can't figure out what's wrong.

请注意，我之所以制作了两个按钮，仅仅是因为

Please note I've made two buttons only because the first didn't work.

我的代码如下：

public class storage extends JFrame{
private JTextField text1;
public JTextArea storearea;
public JButton newsave;
public JButton save;

public storage(UserProfile person) { //constructor with name passed in
    super("Safe Storage");
    setLayout(new FlowLayout());

    JTextField text1 = new JTextField("Using program as: " + (person.getName()) );
    text1.setEditable(false);
    add(text1);

    JTextArea storearea = new JTextArea(person.getText());
    add(storearea);

    JButton newsave = new JButton("Save");
    add(newsave);

    JButton save = new JButton("Save Changes");
    add(save);

    thehandler handler = new thehandler();
    save.addActionListener(handler);
    newsave.addActionListener(handler);
} //end constructor


public class thehandler implements ActionListener { //Handler
       public void actionPerformed(ActionEvent event){
           if(event.getSource() == save) {
               System.out.println("Overwriting text");
               }
           else if(event.getSource() == newsave) {
               System.out.println("Overwriting text new");
           }
       }        
    } //end thehandler
} //end class

推荐答案

您已声明实例变量（为空）；

You have declared an instance variable (which is null);

public JButton newsave;

和一个局部变量：

JButton newsave = new JButton("Save");

您不希望局部变量（仅实例变量），因此代码应为：

You don't want the local variable (only the instance variable), so the code should be:

newsave = new JButton("Save");

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