Swing JFrame類和實例

JFrame類是一個擴展版java.awt.Frame添加JFC/Swing組件架構的支持。

類聲明

以下是聲明 javax.swing.JFrame類：

public class JFrame
   extends Frame
      implements WindowConstants, Accessible
         , RootPaneContainer

字段域

以下是java.awt.Component類的字段：

protected AccessibleContext accessibleContext --訪問上下文屬性。
static int EXIT_ON_CLOSE --退出應用程序默認的窗口關閉操作。
protected JRootPane rootPane --JRootPane實例管理的contentPane和可選的菜單欄，以及該幀的玻璃麵板。
protected boolean rootPaneCheckingEnabled -- 如果為true 則調用添加的setLayout將被轉發到contentPane。

類構造函數

S.N.	構造函數 & 描述
1	JFrame() Constructs a new frame that is initially invisible.
2	JFrame(GraphicsConfiguration gc) Creates a Frame in the specified GraphicsConfiguration of a screen device and a blank title.
3	JFrame(String title) Creates a new, initially invisible Frame with the specified title.
4	JFrame(String title, GraphicsConfiguration gc) Creates a JFrame with the specified title and the specified GraphicsConfiguration of a screen device.

類方法

S.N.	方法 & 描述
1	protected void addImpl(Component comp, Object constraints, int index) Adds the specified child Component.
2	protected JRootPane createRootPane() Called by the constructor methods to create the default rootPane.
3	protected void frameInit() Called by the constructors to init the JFrame properly.
4	AccessibleContext getAccessibleContext() Gets the AccessibleContext associated with this JFrame.
5	Container getContentPane() Returns the contentPane object for this frame.
6	int getDefaultCloseOperation() Returns the operation that occurs when the user initiates a "close" on this frame.
7	Component getGlassPane() Returns the glassPane object for this frame.
8	Graphics getGraphics() Creates a graphics context for this component.
9	JMenuBar getJMenuBar() Returns the menubar set on this frame.
10	JLayeredPane getLayeredPane() Returns the layeredPane object for this frame.
11	JRootPane getRootPane() Returns the rootPane object for this frame.
12	TransferHandler getTransferHandler() Gets the transferHandler property.
13	static boolean isDefaultLookAndFeelDecorated() Returns true if newly created JFrames should have their Window decorations provided by the current look and feel.
14	protected boolean isRootPaneCheckingEnabled() Returns whether calls to add and setLayout are forwarded to the contentPane.
15	protected String paramString() Returns a string representation of this JFrame.
16	protected void processWindowEvent(WindowEvent e) Processes window events occurring on this component.
17	void remove(Component comp) Removes the specified component from the container.
18	void repaint(long time, int x, int y, int width, int height) Repaints the specified rectangle of this component within time milliseconds.
19	void setContentPane(Container contentPane) Sets the contentPane property.
20	void setDefaultCloseOperation(int operation) Sets the operation that will happen by default when the user initiates a "close" on this frame.
21	static void setDefaultLookAndFeelDecorated(boolean defaultLookAndFeelDecorated) Provides a hint as to whether or not newly created JFrames should have their Window decorations (such as borders, widgets to close the window, title...) provided by the current look and feel.
22	void setGlassPane(Component glassPane) Sets the glassPane property.
23	void setIconImage(Image image) Sets the image to be displayed as the icon for this window.
24	void setJMenuBar(JMenuBar menubar) Sets the menubar for this frame.
25	void setLayeredPane(JLayeredPane layeredPane) Sets the layeredPane property.
26	void setLayout(LayoutManager manager) Sets the LayoutManager.
27	protected void setRootPane(JRootPane root) Sets the rootPane property.
28	protected void setRootPaneCheckingEnabled(boolean enabled) Sets whether calls to add and setLayout are forwarded to the contentPane.
29	void setTransferHandler(TransferHandler newHandler) Sets the transferHandler property, which is a mechanism to support transfer of data into this component.
30	void update(Graphics g) Just calls paint(g).

方法繼承

這個類從以下類繼承的方法：

java.awt.Frame
java.awt.Window
java.awt.Container
java.awt.Component
java.lang.Object

JFrame 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.showJFrameDemo();
   }

   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 showJFrameDemo(){
      headerLabel.setText("Container in action: JFrame");   

      final JFrame frame = new JFrame();
      frame.setSize(300, 300);
      frame.setLayout(new FlowLayout());       
      frame.add(msglabel);
      frame.addWindowListener(new WindowAdapter() {
         public void windowClosing(WindowEvent windowEvent){
            frame.dispose();
         }        
      });    
      JButton okButton = new JButton("Open a Frame");
      okButton.addActionListener(new ActionListener() {
         public void actionPerformed(ActionEvent e) {
            statusLabel.setText("A Frame shown to the user.");
            frame.setVisible(true);
         }
      });
      controlPanel.add(okButton);
      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