package com.zf.ui;

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

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

/**
 * 主窗口
 * @author zhoufeng
 *
 */
public class MainFrame {

    JFrame frame = null ;
    JTextArea text = null;
    JButton button = null;

    public void init(){
        frame = new JFrame("主窗口");
        frame.setBounds(500, 250, 500, 300);
        frame.setVisible(true);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        text = new JTextArea();
        text.setSize(100, 50 );  
        text.setText("这里将会显示时间！");
        frame.add(text , BorderLayout.NORTH);

        button = new JButton("打开子窗口");

        frame.add(button , BorderLayout.SOUTH);

        button.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                System.out.println("点击了。");
                new ChildFrame(MainFrame.this);
            }
        });
    }

    public static void main(String[] args) {
        new MainFrame().init();
    }


}


/**
 * 子窗口
 * @author zhoufeng
 *
 */
class ChildFrame{
    MainFrame mainFrame = null;        
    JFrame frame = null;
    JButton button = null;
    public ChildFrame(final MainFrame mainFrame){   
        frame = new JFrame("子窗口");
        frame.setBounds(500, 250, 300, 150);
        frame.setVisible(true);
        button = new JButton("为主窗口中的文本域赋值");
        button.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                mainFrame.text.setText(new Date().toLocaleString());
                frame.setVisible(false);
            }
        });
        frame.add(button , BorderLayout.NORTH);
    }

}

------解决方案--------------------

探讨


引用:
传对象引用。先看下我的代码吧。尤其是
@Override
public void actionPerformed(ActionEvent e) {
if (e.getSource() == createFrame) {
TestFrame f = new TestFrame("新窗体",this);
f.time.setText(new Date()+ "……