JPanel類是一個通用的輕量級容器。

類聲明

以下是javax.swing.JPanel 類的聲明：

public class JPanel
   extends JComponent
      implements Accessible

類構造函數

S.N.	構造函數 & 描述
1	JPanel()  Creates a new JPanel with a double buffer and a flow layout.
2	JPanel(boolean isDoubleBuffered)  Creates a new JPanel with FlowLayout and the specified buffering strategy.
3	JPanel(LayoutManager layout)  Create a new buffered JPanel with the specified layout manager.
4	JPanel(LayoutManager layout, boolean isDoubleBuffered)  Creates a new JPanel with the specified layout manager and buffering strategy.

類方法

S.N.	方法 & 描述
1	AccessibleContext getAccessibleContext()  Gets the AccessibleContext associated with this JPanel.
2	PanelUI getUI()  Returns the look and feel (L&F) object that renders this component.
3	String getUIClassID()  Returns a string that specifies the name of the L&F class that renders this component.
4	protected String paramString()  Returns a string representation of this JPanel.
5	void setUI(PanelUI ui)  Sets the look and feel (L&F) object that renders this component.
6	void updateUI()  Resets the UI property with a value from the current look and feel.

方法繼承

這個類從以下類繼承的方法：

• javax.swing.JComponent

• java.awt.Container

• java.awt.Component

• java.lang.Object

JPanel 例子

選擇使用任何編輯器創建以下java程序在 D:/ > SWING > com > yiibai > gui >

SwingContainerDemo.java

package com.yiibai.gui;

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

public class SwingContainerDemo {
   private JFrame mainFrame;
   private JLabel headerLabel;
   private JLabel statusLabel;
   private JPanel controlPanel;
   private JLabel msglabel;

   public SwingContainerDemo(){
      prepareGUI();
   }

   public static void main(String[] args){
      SwingContainerDemo  swingContainerDemo = new SwingContainerDemo();  
      swingContainerDemo.showJPanelDemo();
   }

   private void prepareGUI(){
      mainFrame = new JFrame("Java Swing Examples");
      mainFrame.setSize(400,400);
      mainFrame.setLayout(new GridLayout(3, 1));
      mainFrame.addWindowListener(new WindowAdapter() {
         public void windowClosing(WindowEvent windowEvent){
            System.exit(0);
         }        
      });    
      headerLabel = new JLabel("", JLabel.CENTER);        
      statusLabel = new JLabel("",JLabel.CENTER);    

      statusLabel.setSize(350,100);

      msglabel = new JLabel("Welcome to TutorialsPoint SWING Tutorial."
         , JLabel.CENTER);

      controlPanel = new JPanel();
      controlPanel.setLayout(new FlowLayout());

      mainFrame.add(headerLabel);
      mainFrame.add(controlPanel);
      mainFrame.add(statusLabel);
      mainFrame.setVisible(true);  
   }


   private void showJPanelDemo(){
      headerLabel.setText("Container in action: JPanel");      

      JPanel panel = new JPanel();
      panel.setBackground(Color.magenta);
      panel.setLayout(new FlowLayout());        
      panel.add(msglabel);

      controlPanel.add(panel);        
      mainFrame.setVisible(true);      
   }   
}

編譯程序，使用命令提示符。到 D:/ > SWING 然後輸出以下命令。

D:SWING>javac comyiibaiguiSwingContainerDemo.java

如果冇有錯誤出現，這意味著編譯成功。使用下麵的命令來運行程序。

D:SWING>java com.yiibai.gui.SwingContainerDemo

驗證下麵的輸出