将JButton操作从一个类传递到另一个类的JTextfield

Question

I am experimenting JButton's action and I am trying to clear a textfield in class Test2 using a button in class Test1. Here is the code

public class Test2 {
private JFrame frame;
private JTextField t1;
private JTextField t2;

/**
 * Launch the application.
 */
public void start() {
    EventQueue.invokeLater(new Runnable() {
        public void run() {
            try {
                test2 window = new test2();
                window.frame.setVisible(true);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    });
}

/**
 * Create the application.
 */
public test2() {
    initialize();
}
public void Reset(){
    t1 = new JTextField();
    t1.setText("");

}
/**
 * Initialize the contents of the frame.
 */
private void initialize() {
    frame = new JFrame();
    frame.setBounds(100, 100, 450, 300);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    t1 = new JTextField();
    t1.setColumns(10);
    t1.setText("Start");


    GroupLayout groupLayout = new GroupLayout(frame.getContentPane());
    groupLayout.setHorizontalGroup(
        groupLayout.createParallelGroup(Alignment.LEADING)
            .addGroup(groupLayout.createSequentialGroup()
                .addGap(35)
                .addGroup(groupLayout.createParallelGroup(Alignment.LEADING)
                    .addComponent(t2, GroupLayout.PREFERRED_SIZE, GroupLayout.DEFAULT_SIZE, GroupLayout.PREFERRED_SIZE)
                    .addComponent(t1, GroupLayout.PREFERRED_SIZE, GroupLayout.DEFAULT_SIZE, GroupLayout.PREFERRED_SIZE))
                .addContainerGap(281, Short.MAX_VALUE))
    );
    groupLayout.setVerticalGroup(
        groupLayout.createParallelGroup(Alignment.LEADING)
            .addGroup(groupLayout.createSequentialGroup()
                .addGap(38)
                .addComponent(t1, GroupLayout.PREFERRED_SIZE, GroupLayout.DEFAULT_SIZE, GroupLayout.PREFERRED_SIZE)
                .addGap(75)
                .addComponent(t2, GroupLayout.PREFERRED_SIZE, GroupLayout.DEFAULT_SIZE, GroupLayout.PREFERRED_SIZE)
                .addContainerGap(98, Short.MAX_VALUE))
    );
    frame.getContentPane().setLayout(groupLayout);
}

}

public class Test1 {

private JFrame frame;



/**
 * Launch the application.
 */
static test1 window = new test1();
static test2 window2 = new test2();
private JTextField textField;
private JTextField ownText;
public static void main(String[] args) {
    EventQueue.invokeLater(new Runnable() {
        public void run() {
            try {
                window2.start();
                window.frame.setVisible(true);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    });
}

/**
 * Create the application.
 * @wbp.parser.entryPoint
 */
public test1() {
    initialize();
}

/**
 * Initialize the contents of the frame.
 */
private void initialize() {
    frame = new JFrame();
    frame.setBounds(100, 100, 450, 300);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    JButton btnNewButton = new JButton("New button");
    btnNewButton.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent arg0) {
            String test ="";
            window2.Reset(test);

        }
    });
    frame.getContentPane().add(btnNewButton, BorderLayout.WEST);

    ownText = new JTextField();
    frame.getContentPane().add(ownText, BorderLayout.EAST);
    ownText.setColumns(10);


}

}

At the moment, when I click the button in Test1 class, the textfield in Test2 class is not cleared. Hope to have advice from all the seniors here. Let me know too if my questions has any shortcomings. Thank you so much.

Answer 1

Updated your Reset() method with this

public void Reset(){
        t1.setText("");     
}

You can't instantiate the Text Field again in Reset method.Because frame contain text field.Please read the Java Coding rule use reset() instead of Reset()

UPDATED Also one thing is you use two instant of Test2 . So you make your start() method in Test2 like that

public void start() {
    EventQueue.invokeLater(new Runnable() {
        public void run() {
            try {
                //test2 window = new test2();
                 frame.setVisible(true);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    });
}