Java图形化界面设计之布局管理器之BorderLayout案例详解

// BorderLayoutDemo.java

import javax.swing.*;

import java.awt.*;

public class BorderLayoutDemo extends JFrame {

  public BorderLayoutDemo(){        //构造函数，初始化对象值

     //设置为边界布局，组件间横向、纵向间距均为5像素

setLayout(new BorderLayout(5,5)); 

     setFont(new Font("Helvetica", Font.PLAIN, 14));

     getContentPane().add("North", new JButton("North"));     //将按钮添加到窗口中

     getContentPane().add("South", new JButton("South"));

     getContentPane().add("East",  new JButton("East"));

     getContentPane().add("West",  new JButton("West"));

     getContentPane().add("Center",new JButton("Center"));

  }  

  public static void main(String args[]) {

     BorderLayoutDemo f = new BorderLayoutDemo();

       f.setTitle("边界布局");

       f.pack();

       f.setVisible(true);

            f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

            f.setLocationRelativeTo(null);             //让窗体居中显示

    }

  }

// BorderLayoutDemo1.java

import javax.swing.*;

import java.awt.*;

public class BorderLayoutDemo1 extends JFrame {

         JPanel p=new JPanel();

  public BorderLayoutDemo(){

     setLayout(new BorderLayout(5,5));

     setFont(new Font("Helvetica", Font.PLAIN, 14));

     getContentPane().add("North", new JButton("North"));

     getContentPane().add("South", new JButton("South"));

     getContentPane().add("East",  new JButton("East"));

     getContentPane().add("West",  new JButton("West"));

         //设置面板为流式布局居中显示，组件横、纵间距为5个像素

          p.setLayout(new FlowLayout(1,5,5));

          //使用循环添加按钮，注意每次添加的按钮对象名称都是b

//但按钮每次均是用new新生成的，所有代表不同的按钮对象。

          for(int i=1;i<10;i++){

                    //String.valueOf(i)，将数字转换为字符串

                   JButton b=new JButton(String.valueOf(i));

                   p.add(b);           //将按钮添加到面板中

          }

     getContentPane().add("Center",p);  //将面板添加到中间位置

  }  

  public static void main(String args[]) {

     BorderLayoutDemo1 f = new BorderLayoutDemo1();

       f.setTitle("边界布局");

       f.pack();  //让窗体自适应组建大小

       f.setVisible(true);

            f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

            f.setLocationRelativeTo(null);             //让窗体居中显示

    }

  }