在界面设计中，一个容器要放置许多组件，为了美观，将组件安排在容器的不同位置这就是布局设计，常用有以下布局类

1.FlowLayout

import java.awt.Container;
import java.awt.FlowLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
/**
 * 将组件已加入顺序从左到右排序，一行
 * 排满就会去第二行。
 * 每行组件剧中排列
 * @author 持剑的龙套
 *
 */
public class FlowLayoutDemo {

    private JFrame frame;
    private JButton button1,button2,button3,button4,button5;

    public static void main(String[] args) {
        FlowLayoutDemo fd = new FlowLayoutDemo();
        fd.go();
    }

    private void go() {
        frame = new JFrame("flowlayout");
        Container contentPane = frame.getContentPane();
        contentPane.setLayout(new FlowLayout());
        button1 = new JButton("OK");
        button2 = new JButton("OPEN");
        button3 = new JButton("CLOSE");
        button4 = new JButton("aaa");
        button5 = new JButton("CLOSEccc");
        contentPane.add(button1);
        contentPane.add(button2);
        contentPane.add(button3);
        contentPane.add(button4);
        contentPane.add(button5);
        frame.setSize(300,200);
        frame.setVisible(true);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }
}

运行结果如下

2.BorderLayout

import java.awt.BorderLayout;
import javax.swing.JButton;
import javax.swing.JFrame;

/**
 * 由BorderLayout管理的容器被划分为5个区域
 * North  south  west east  center
 * @author 持剑的龙套
 *
 */
public class BorderLayoutDemo {
    private JFrame frame;
    private JButton be,bw,bn,bs,bc;

    public static void main(String[] args) {
        BorderLayoutDemo bd = new BorderLayoutDemo();
        bd.go();
    }

    private void go() {

        frame = new JFrame("BorderLayoutDemo");
        be = new JButton("east");
        bw = new JButton("west");
        bn = new JButton("north");
        bs = new JButton("south");
        bc = new JButton("center");
        frame.getContentPane().add(be,BorderLayout.EAST);
        frame.getContentPane().add(bw,BorderLayout.WEST);
        frame.getContentPane().add(bn,BorderLayout.NORTH);
        frame.getContentPane().add(bs,BorderLayout.SOUTH);
        frame.getContentPane().add(bc,BorderLayout.CENTER);

        frame.setSize(300, 200);
        frame.setVisible(true);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);   
    }

}

运行结果如下

3.GridLayout

import java.awt.Container;
import java.awt.Dimension;
import java.awt.GridLayout;

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

/**
 * 将容器分为若干行和列，组件依次放入其中
 * 每个组件占据一格。
 * @author 持剑的龙套
 *
 */
public class GridLayoutDemo {
    public static void main(String[] args) {
        MyWindow that = new MyWindow();
        that.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }
}

@SuppressWarnings("serial")
class MyWindow extends JFrame {
    private JButton b1,b2,b3,b4,b5,b6;
    public MyWindow() {
        setTitle("grid");
        Container contentPane = getContentPane();
        contentPane.setPreferredSize(new Dimension(400,300));
        contentPane.setLayout(new GridLayout(3,2));//3行2列
        b1 =new JButton("b1");
        b2 =new JButton("b2");
        b3 =new JButton("b3");
        b4 =new JButton("b4");
        b5 =new JButton("b5");
        b6 =new JButton("b6");
        contentPane.add(b1);
        contentPane.add(b2);
        contentPane.add(b3);
        contentPane.add(b4);
        contentPane.add(b5);
        contentPane.add(b6);
        pack();
        setVisible(true);
    }
}

运行结果如下

4.BoxLayout

import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.FlowLayout;
import java.awt.Label;

import javax.swing.BoxLayout;
import javax.swing.JFrame;
import javax.swing.JPanel;

/**
 * 将容器中的组件水平或者竖直排成一行或一列
 * @author 持剑的龙套
 *
 */
public class BoxLayoutDemo {

    private JFrame jFrame;
    private JPanel jPanel,jPanel2;
    public static void main(String[] args) {
        BoxLayoutDemo boxLayoutDemo = new BoxLayoutDemo();
        boxLayoutDemo.go();

    }
    private void go () {
        jFrame = new JFrame("box lay");
        Container contentPane = jFrame.getContentPane();
        jPanel = new JPanel();
        jPanel.setLayout(new BoxLayout(jPanel, BoxLayout.Y_AXIS));
        jPanel.add(new Label("1"));
        jPanel.add(new Label("2"));
        jPanel.add(new Label("3"));
        contentPane.add(jPanel, BoxLayout.X_AXIS);
        jPanel2 = new JPanel();
        jPanel2.setLayout(new BoxLayout(jPanel2, BoxLayout.X_AXIS));
        jPanel2.add(new Label("yes"));
        jPanel2.add(new Label("no"));
        jPanel2.add(new Label("cancel"));
        //contentPane.add(jPanel2,BorderLayout.SOUTH);
        //contentPane.add(jPanel2,FlowLayout.CENTER);
        jFrame.pack();
        jFrame.setVisible(true);
        jFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }
}

运行结果如下

5.CradLayout

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

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;

/**
 * 卡片布局 每时每刻只显示一张
 * @author 持剑的龙套
 *
 */
@SuppressWarnings("serial")
public class CardlayoutDemo extends JFrame {

    public static void main(String[] args) {
        new CardlayoutDemo();
    }

    public CardlayoutDemo() {
          this.setTitle("Cardlayout");
          this.setSize(400, 400);
          this.setLocationRelativeTo(null);
          this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
          Container c = this.getContentPane();
          JButton jbtn1 = new JButton("上一个");
          c.add(jbtn1, BorderLayout.NORTH);
          final JPanel mainJPanel = new JPanel(); 
          //匿名内部类只能访问final变量
          final CardLayout cardLayout = new CardLayout(); 
          mainJPanel.setLayout(cardLayout);
          mainJPanel.add(new JLabel("第1张"), "one"); 
          mainJPanel.add(new JLabel("第2张"), "two");
          mainJPanel.add(new JLabel("第3张"), "three");
          mainJPanel.add(new JLabel("第4张"), "four");
          c.add(mainJPanel, BorderLayout.CENTER); 
          JButton jbtn2 = new JButton("下一个"); 
          c.add(jbtn2, BorderLayout.SOUTH); 

          jbtn1.addActionListener(new ActionListener() {  
           public void actionPerformed(ActionEvent e) {  
            cardLayout.previous(mainJPanel);
           }  
          });  
          jbtn2.addActionListener(new ActionListener() {  
           public void actionPerformed(ActionEvent e) {  
            cardLayout.next(mainJPanel);
           }  
          });  
          //cardLayout.show(mainJPanel, "three");
          this.setVisible(true);
    }
}

虽然没人用，但是考试会有….