JAVA Swing:Can'；t将文本区域添加到边框布局

MainFrame.java

import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JTextArea;

public class MainFrame extends JFrame{

    private JTextArea textArea;
    private JButton btn;
    private TextPanel textPanel;

    public MainFrame() {

        super("My First JAVA Swing Window");
        setLayout(new BorderLayout());

        textArea = new JTextArea();
        btn = new JButton("Click Me");
        textPanel = new TextPanel();


        btn.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent arg0) {
                textArea.append("Button has been clicked!\n");
                //textPanel.appendText("Button has been clicked!\n");
            }
        });

        add(textArea, BorderLayout.CENTER);
        add(btn, BorderLayout.SOUTH);

        setSize(600,500);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setVisible(true);
    }

}

import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JTextArea;

public class MainFrame extends JFrame{

    //private JTextArea textArea;
    private JButton btn;
    private TextPanel textPanel;

    public MainFrame() {

        super("My First JAVA Swing Window");
        setLayout(new BorderLayout());

        //textArea = new JTextArea();
        btn = new JButton("Click Me");
        textPanel = new TextPanel();


        btn.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent arg0) {
                //textArea.append("Button has been clicked!\n");
                textPanel.appendText("Button has been clicked!\n");
            }
        });

        //add(textArea, BorderLayout.CENTER);
        add(btn, BorderLayout.SOUTH);

        setSize(600,500);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setVisible(true);
    }

}

我的目标是，如果我单击按钮，则向文本区域添加文本（按钮已被单击！）。我设法做到了，但我试图在另一个类中分离文本区域，如果我将其分离，它将不再起作用。。我看到的是，它甚至不添加文本区域的边界布局。。。这就是我试图分离的方式，这是不起作用的部分： MainFrame.java

import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JTextArea;

public class MainFrame extends JFrame{

    private JTextArea textArea;
    private JButton btn;
    private TextPanel textPanel;

    public MainFrame() {

        super("My First JAVA Swing Window");
        setLayout(new BorderLayout());

        textArea = new JTextArea();
        btn = new JButton("Click Me");
        textPanel = new TextPanel();


        btn.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent arg0) {
                textArea.append("Button has been clicked!\n");
                //textPanel.appendText("Button has been clicked!\n");
            }
        });

        add(textArea, BorderLayout.CENTER);
        add(btn, BorderLayout.SOUTH);

        setSize(600,500);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setVisible(true);
    }

}

import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JTextArea;

public class MainFrame extends JFrame{

    //private JTextArea textArea;
    private JButton btn;
    private TextPanel textPanel;

    public MainFrame() {

        super("My First JAVA Swing Window");
        setLayout(new BorderLayout());

        //textArea = new JTextArea();
        btn = new JButton("Click Me");
        textPanel = new TextPanel();


        btn.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent arg0) {
                //textArea.append("Button has been clicked!\n");
                textPanel.appendText("Button has been clicked!\n");
            }
        });

        //add(textArea, BorderLayout.CENTER);
        add(btn, BorderLayout.SOUTH);

        setSize(600,500);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setVisible(true);
    }

}

TextPanel.java

import java.awt.BorderLayout;

import javax.swing.JPanel;
import javax.swing.JTextArea;

public class TextPanel extends JPanel{

    private JTextArea textArea;

    public TextPanel() {

        textArea = new JTextArea();
        setLayout(new BorderLayout());
        add(textArea, BorderLayout.CENTER);
    }

    public void appendText(String text) {
        textArea.append(text);
    }
}

---

当然还有一个运行大型机的主类…

问题是您调用了

add（textArea，BorderLayout.CENTER）MainFrame.java

中。 那里的

add

方法将

textArea

添加到

JFrame

的布局中

但之后，您不会将

TextPanel

添加到

JFrame

，而只将其添加到

JPanel

的本地

BorderLayout

。没有在任何地方添加

BorderLayout

---

如果您仍然调用

add（textPanel，BorderLayout.CENTER）

，它应该可以工作

是的，我没有把文本面板添加到主机的边框布局中。。。非常感谢你！