目录

 布局管理器

4.1.FlowLayout

4.2.BorderLayout

4.3.GridLayout

4.4.CardLayout

4.5.BoxLayout

4.6.NULL

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 布局管理器

布局是指组件在容器中的排列方式，主要有：

                                                        FlowLayout       流式布局

                                                        BorderLayout    边界布局

                                                        GridLayout        网格布局

                                                        CardLayout       卡片布局

                                                        BoxLayout         盒式布局

                                                        GridBagLayout  网格包布局

                                                        null                    空布局（不使用布局）

注：对于一些复杂的情况，往往需要使用容器的嵌套，各容器可使用不同的布局。当容器的尺寸改变时，布局管理器会自动调整组件的排列

4.1.FlowLayout

• 该布局以行为单位依次排列各组件，一行排不下时，另起一行

• JPanel的默认布局是FlowLayout
• 构造方法

                        FlowLayout();
                        FlowLayout(int align); //align一般取值有：CENTER、LEFT、RIGHT
                        FlowLayout(int align, int hgap, int vgap);//hgap和vgap指定组件与容器起始边界以及组件间的水平和垂直间距，默认值为5个像素

• 例如：FlowLayout layout = new FlowLayout(FlowLayout.LEFT, 10, 10);
• 缺点：当用户对由FlowLayout布局管理的区域进行缩放时，布局发生变化

• 该布局适用于组件个数较少的情况

import javax.swing.*;
import java.awt.*;

public class JFrame_MainClass  {
    public static void main(String[] args) {
        new MyJFrame();
    }
}
class MyJFrame extends JFrame{
    private JPanel panel;
    private JButton button1,button2;
    public MyJFrame(){
        super("JPanel默认布局：FlowLayout");
    //    panel = new JPanel(); //  默认居中对齐
        panel = new JPanel(new FlowLayout(FlowLayout.LEFT)); // 设置左对齐
        button1 = new JButton("button1");
        button2 = new JButton("button2");
        panel.add(button1);
        panel.add(button2);
        this.add(panel);
        this.setSize(300,200);
        this.setLocation(200,100);
        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        this.setVisible(true);
    }
}

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4.2.BorderLayout

• 按照东、西、南、北、中5个方位排列各组件
• 顶层容器JFrame、JApplet、JDialog、JWindow的默认布局都是BorderLayout

• 构造方法:

BorderLayout( );
BorderLayout(int hgap,int vgap);//hgap和vgap指定组件间的水平和垂直间距，默认值为0个像素

• 例如：

BorderLayout lay1 = new BorderLayout( );
BorderLayout lay2 = new BorderLayout(10, 10);

• 方位的取值为：

BorderLayout.EAST    或 “East”
BorderLayout.WEST    或  “West”
BorderLayout.SOUTH   或  “South”
BorderLayout.NORTH   或  “North”
BorderLayout.CENTER  或  “Center”(默认)
设置容器布局：setLayout（方位）;

• 缺点：当加入的组件超过5个时，就必须使用容器的嵌套或其它布局。
• 优点：当容器缩放时，组件相应的位置不变化，但大小改变。

import javax.swing.*;
import java.awt.*;

public class MainClass{
    public static void main(String[] args) {
        new BorderLayout_3();
    }
}
class BorderLayout_3 extends JFrame {
    public BorderLayout_3(){
       super("JFrame默认布局：BorderLayout");
       JPanel panel = new JPanel(new BorderLayout());
       JButton button1 = new JButton("按钮1");
       JButton button2 = new JButton("按钮2");
       JButton button3 = new JButton("按钮3");
       JButton button4 = new JButton("按钮4");
       JButton button5 = new JButton("按钮5");
       panel.add(button1,BorderLayout.EAST);
       panel.add(button2,BorderLayout.WEST);
       panel.add(button3,BorderLayout.SOUTH);
       panel.add(button4,BorderLayout.NORTH);
       panel.add(button5,BorderLayout.CENTER);
       this.add(panel);
       this.setSize(400,360);
       this.setLocation(300,200);
       this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
       this.setVisible(true);
    }

}

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4.3.GridLayout

• 按照二维网格以相同大小依次排列各组件

• 构造方法:

                GridLayout();//一行、每个组件一列
                GridLayout(int rows,int cols);//行列数
                GridLayout(int rows, int cols, int hgap, int vgap);//行行、列列的间距，默认值为0个像素

• 例如：

                GridLayout lay1 = new GridLayout(3,3);
                GridLayout lay2 = new GridLayout(5,2,10,10);

• 优点：组件的相应位置不随区域的缩放而改变，只是组件的大小改变。

• 该布局适用于组件个数较多的情况。

import javax.swing.*;
import java.awt.*;

public class MainClass{
    public static void main(String[] args) {
        new GridLayout_5();
    }
}
class GridLayout_5 extends JFrame {
    private JPanel panel;
    public GridLayout_5(){
       super("GridLayout布局");
       panel = new JPanel(new GridLayout(2,3));
       for (int i = 0; i < 6; i++) {
            panel.add(new JButton("按钮"+(i+1)));
       }
       this.add(panel);
       this.setSize(400,360);
       this.setLocation(300,200);
       this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
       this.setVisible(true);
    }
}

---

 

4.4.CardLayout

• 该布局以一叠卡片的形式依次排列各组件

构造方法

• CardLayout( );
• CardLayout(int hgap,int vgap);//组件与容器边界间距，默认值为0个像素

例如：

•  CardLayout layout1 = new CardLayout();
•  CardLayout layout2 = new CardLayout(10,10);

显示方法	功能
first(Container con)	显示容器中的第一张卡片
last(Container con)	显示容器中的最后一张卡片
previous(Container con)	显示容器中当前卡片的上一张卡片
next(Container con)	显示容器中当前卡片的下一张卡片
show(Container con, String name)	显示容器中指定名称的卡片

import javax.swing.*;
import java.awt.*;

class MainClass{
    public static void main(String[] args) {
        new CardLayout_4();
    }
}
class CardLayout_4 extends JFrame {
    private JPanel panel;
    private CardLayout cardLayout;
    public CardLayout_4(){
       super("CardLayout布局");
       panel = new JPanel();
       cardLayout = new CardLayout();
       panel.setLayout(cardLayout);

       for (int i = 0; i < 5; i++) {
           panel.add(new JButton("按钮"+(i+1)));
       }
       cardLayout.last(panel);  // 显示最后一张卡片（按钮）
       this.add(panel);
       this.setSize(400,360);
       this.setLocation(300,200);
       this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
       this.setVisible(true);
    }
}

---

4.5.BoxLayout

• 以一行或一列的方式依次排列各组件

构造方法：

• new BoxLayout(Container con, int axis)：创建一个指定容器和方向的BoxLayout对象

常量	描述
BorderLayout.X_AXIS	X轴（横轴）排列
BorderLayout.Y_AXIS	Y轴（纵轴）排列
LINE_AXIS	根据容器的Component Oriebtation属性，按照文字在一行中的排列方式布置组件
PAGE_AXIS	根据容器的Component Oriebtation属性，按照文本行在一页中的排列方式布置组件

import javax.swing.*;

public class MainClass{
    public static void main(String[] args) {
        new BoxLayout_6();
    }
}
class BoxLayout_6 extends JFrame {
    private JPanel panel;
    public BoxLayout_6(){
       super("BoxLayout布局");
       panel = new JPanel();
       panel.setLayout(new BoxLayout(panel, BoxLayout.Y_AXIS)); //  沿Y轴布置组件

       for (int i = 0; i < 5; i++) {
            panel.add(new JButton("按钮"+(i+1)));
       }
       this.add(panel);
       this.setSize(400,360);
       this.setLocation(300,200);
       this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
       this.setVisible(true);
    }
}

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4.6.NULL

• 不使用任何布局管理器

空布局的使用:

• 创建容器对象：JPanel panel = new JPanel( );
• 设置容器对象的布局为null：panel.setLayout(null);
• 设置组件在容器中的位置：组件对象.setBounds(x, y, width, height);

import javax.swing.*;

public class MainClass{
    public static void main(String[] args) {
        new null_7();
    }
}
class null_7 extends JFrame {
     private Jpanel panel;
     private JButton button1,button2,button3,button4,button5;
     public null_7(){
       super("null布局");
       panel = new JPanel();
       panel.setLayout(null);
       button1 = new JButton("按钮1");
       button2 = new JButton("按钮2");
       button3 = new JButton("按钮3");
       button4 = new JButton("按钮4");
       button5 = new JButton("按钮5");

       button1.setBounds(35,25,75,30);
       button2.setBounds(135,25,75,30);
       button3.setBounds(235,25,75,30);
       button4.setBounds(35,65,75,30);
       button5.setBounds(135,65,75,30);

       panel.add(button1);
       panel.add(button2);
       panel.add(button3);
       panel.add(button4);
       panel.add(button5);

       this.add(panel);
       this.setSize(400,360);
       this.setLocation(300,200);
       this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
       this.setVisible(true);
    }
}

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(27条消息) Swing UI——容器（一）_Stuttering Guy的博客-CSDN博客https://blog.csdn.net/Mr_Morgans/article/details/125109643?csdn_share_tail=%7B%22type%22%3A%22blog%22%2C%22rType%22%3A%22article%22%2C%22rId%22%3A%22125109643%22%2C%22source%22%3A%22Mr_Morgans%22%7D&ctrtid=l9JMT(27条消息) Swing UI——基本组件（二）_Stuttering Guy的博客-CSDN博客https://blog.csdn.net/Mr_Morgans/article/details/125110881?csdn_share_tail=%7B%22type%22%3A%22blog%22%2C%22rType%22%3A%22article%22%2C%22rId%22%3A%22125110881%22%2C%22source%22%3A%22Mr_Morgans%22%7D&ctrtid=Kzbcx(27条消息) Swing UI——高级组件（三）_Stuttering Guy的博客-CSDN博客https://blog.csdn.net/Mr_Morgans/article/details/125115383?csdn_share_tail=%7B%22type%22%3A%22blog%22%2C%22rType%22%3A%22article%22%2C%22rId%22%3A%22125115383%22%2C%22source%22%3A%22Mr_Morgans%22%7D&ctrtid=81Bbq(27条消息) Swing UI——事件处理（五）_Stuttering Guy的博客-CSDN博客https://blog.csdn.net/Mr_Morgans/article/details/125115417?spm=1001.2014.3001.5501