Question

java中用setTitel和JFrame给窗体命名的区别

如题，求解

Answer 1

下面是一个计算器的例子：

import java.awt.BorderLayout;

import java.awt.Dimension;

import java.awt.GridLayout;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

 

import javax.swing.JButton;

import javax.swing.JFrame;

import javax.swing.JPanel;

import javax.swing.JTextField;

import javax.swing.SwingConstants;

import javax.swing.UIManager;

 

public class ButtonArrayExample extends JFrame { // 继承窗体类JFrame

    /**

     *

     */

    private static final long serialVersionUID = 6626440733001287873L;

    private JTextField textField;

 

    public static void main(String args[]) {

        try {

            UIManager.setLookAndFeel("com.sun.java.swing.plaf.nimbus.NimbusLookAndFeel");

        } catch (Throwable e) {

            e.printStackTrace();

        }

        ButtonArrayExample frame = new ButtonArrayExample();

        frame.setVisible(true); // 设置窗体可见，默认为不可见

    }

 

    public ButtonArrayExample() {

        super(); // 继承父类的构造方法

        BorderLayout borderLayout = (BorderLayout) getContentPane().getLayout();

        borderLayout.setHgap(20);

        borderLayout.setVgap(10);

        setTitle("按钮数组实现计算器界面 "); // 设置窗体的标题

        setBounds(100, 100, 290, 282); // 设置窗体的显示位置及大小

        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); // 设置窗体关闭按钮的动作为退出

        textField = new JTextField();

        textField.setHorizontalAlignment(SwingConstants.TRAILING);

        textField.setPreferredSize(new Dimension(12, 50));

        getContentPane().add(textField, BorderLayout.NORTH);

        textField.setColumns(10);

        final GridLayout gridLayout = new GridLayout(4, 0); // 创建网格布局管理器对象

        gridLayout.setHgap(5); // 设置组件的水平间距

        gridLayout.setVgap(5); // 设置组件的垂直间距

        JPanel panel = new JPanel(); // 获得容器对象

        panel.setLayout(gridLayout); // 设置容器采用网格布局管理器

        getContentPane().add(panel, BorderLayout.CENTER);

        String[][] names = { { "1", "2", "3", "＋" }, { "4", "5", "6", "－" }, { "7", "8", "9", "×" }, { ".", "0", "=", "÷" } };

        JButton[][] buttons = new JButton[4][4];

        for (int row = 0; row < names.length; row++) {

            for (int col = 0; col < names.length; col++) {

                buttons[row][col] = new JButton(names[row][col]); // 创建按钮对象

                buttons[row][col].addActionListener(new ActionListener() {

 

                    @Override

                    public void actionPerformed(ActionEvent e) {

                        JButton button = (JButton) e.getSource();

                        String text = textField.getText();

                        textField.setText(text + button.getText());

                    }

                });

                panel.add(buttons[row][col]); // 将按钮添加到面板中

            }

        }

    }

 

}

运行结果如下:

Answer 2

把另一个JFrame对象设为该Swing窗体的成员变量。
如
import java.awt.HeadlessException;

import javax.swing.JFrame;

/**
* @author wsj
* @date 2010-8-30, 下午03:27:31
*/
public class AFrame extends JFrame{
private BFrame bFrame;//把bFrame设置为该类的成员变量，通过setter方法或构造方法初始化

public void setbFrame(BFrame bFrame) {
this.bFrame = bFrame;
}

private AFrame(BFrame bFrame) throws HeadlessException {
super();
this.bFrame = bFrame;
}

}

class BFrame extends JFrame{

}