java swing 布局_Java的Swing布局

一、流布局FlowLayout

默认地，自左向右逐个排列

当一行排满时，自动排到下一行

setPreferredSize()：控制每个控件的显示高度和宽度

案例效果

MyFrame.java

packageswing布局;import javax.swing.*;import java.awt.*;public class MyFrame extendsJFrame {publicMyFrame(String title){super(title);

Container contentPane=getContentPane();//这里的参数设置的是对齐方式FlowLayout.LEFT左对齐

LayoutManager layout=newFlowLayout(FlowLayout.LEFT);

contentPane.setLayout(layout);

JLabel a1=new ColorfulLabel(“1”,Color.YELLOW);

JLabel a2=new ColorfulLabel(“2”,Color.GREEN);

JLabel a3=new ColorfulLabel(“3”,Color.LIGHT_GRAY);

JLabel a4=new ColorfulLabel(“4”,Color.CYAN);

JLabel a5=new ColorfulLabel(“5”,Color.WHITE);

contentPane.add(a1);

contentPane.add(a2);

contentPane.add(a3);

contentPane.add(a4);

contentPane.add(a5);//设置宽和高

a4.setPreferredSize(new Dimension(150,30));

}private static class ColorfulLabel extendsJLabel{publicColorfulLabel(String text,Color bgColor){super(text);

setOpaque(true);

setBackground(bgColor);

setPreferredSize(new Dimension(60,30));

setHorizontalAlignment(SwingConstants.CENTER);

}

}

}

SwingDemo.java

packageswing布局;import javax.swing.*;public classSwingDemo {private static voidCreateGUI(){

JFrame frame=new MyFrame(“流布局”);

frame.setSize(400,300);

frame.setVisible(true);

}public static voidmain(String[] args) {

SwingUtilities.invokeLater(newRunnable() {

@Overridepublic voidrun() {

CreateGUI();

}

});

}

}

二、边界布局BorderLayout

把容器分为上、下、左、右、中五个区域

setPreferredSize()

对于上下边界，可以调整高度

对于左右边界，可以调整宽度

运行结果

MyFrame2.java

packageswing布局;import javax.swing.*;import java.awt.*;public class MyFrame2 extendsJFrame {publicMyFrame2(String title){super(title);

Container contentPane=getContentPane();

contentPane.setLayout(newBorderLayout());

JLabel a1=new ColorfulLabel(“1”,Color.YELLOW);

JLabel a2=new ColorfulLabel(“2”,Color.GREEN);

JLabel a3=new ColorfulLabel(“3”,Color.LIGHT_GRAY);

JLabel a4=new ColorfulLabel(“4”,Color.CYAN);

JLabel a5=new ColorfulLabel(“5”,Color.WHITE);//五个区域

contentPane.add(a1,BorderLayout.PAGE_START);

contentPane.add(a2,BorderLayout.PAGE_END);

contentPane.add(a3,BorderLayout.LINE_START);

contentPane.add(a4,BorderLayout.LINE_END);

contentPane.add(a5,BorderLayout.CENTER);//设置宽和高

a1.setPreferredSize(new Dimension(0,80));

a3.setPreferredSize(new Dimension(100,0));

}private static class ColorfulLabel extendsJLabel{publicColorfulLabel(String text,Color bgColor){super(text);

setOpaque(true);

setBackground(bgColor);

setPreferredSize(new Dimension(60,30));

setHorizontalAlignment(SwingConstants.CENTER);

}

}

}

SwingDemo02.java

packageswing布局;import javax.swing.*;public classSwingDemo02 {private static voidCreateGUI(){

JFrame frame=new MyFrame2(“边界布局”);

frame.setSize(400,300);

frame.setVisible(true);

}public static voidmain(String[] args) {

SwingUtilities.invokeLater(newRunnable() {

@Overridepublic voidrun() {

CreateGUI();

}

});

}

}

三、卡片布局CardLayout

运行结果

通过切换下拉框的内容切换卡片

MyFrame3.java

packageswing布局;import javax.swing.*;import java.awt.*;importjava.awt.event.ItemEvent;importjava.awt.event.ItemListener;public class MyFrame3 extendsJFrame {

JPanel cards=newJPanel();

JComboBox options=new JComboBox<>();publicMyFrame3(String title){super(title);//内容面板

Container contentPane=getContentPane();

contentPane.setLayout(newBorderLayout());//向下拉框列表添加内容

options.addItem(“第一个面板”);

options.addItem(“第二个面板”);//将下拉框添加至边界布局的顶部

contentPane.add(options,BorderLayout.PAGE_START);//将卡片布局添加至边界布局的center

contentPane.add(cards,BorderLayout.CENTER);//创建第一个面板

JPanel p1=newJPanel();

p1.add(new JButton(“红”));

p1.add(new JButton(“绿”));

p1.add(new JButton(“蓝”));//创建第二个面板

JPanel p2=newJPanel();

p2.add(new JLabel(“输入”));

p2.add(new JTextField(20));//将这两个面板添加到卡片布局中,其中的第二个参数为布局的名称，方便调用

cards.setLayout(newCardLayout());

cards.add(p1,”buttons”);

cards.add(p2,”text”);//添加事件响应

options.addItemListener(newItemListener() {

@Overridepublic voiditemStateChanged(ItemEvent e) {

ItemChange();

}

});

}private voidItemChange() {

CardLayout cardLayout=(CardLayout)cards.getLayout();int index=options.getSelectedIndex();

System.out.println(index);if (index==0){

cardLayout.show(cards,”buttons”);

}else if(index==1){

cardLayout.show(cards,”text”);

}

}

}

SwingDemo03.java

packageswing布局;import javax.swing.*;public classSwingDemo03 {private static voidCreateGUI(){

JFrame frame=new MyFrame3(“卡片布局”);

frame.setSize(400,300);

frame.setVisible(true);

}public static voidmain(String[] args) {

SwingUtilities.invokeLater(newRunnable() {

@Overridepublic voidrun() {

CreateGUI();

}

});

}

}