AWT » AWT CardLayout

AWT CardLayout

介紹

CardLayout類排列一張牌的容器中的每個元件。只有一張卡是可見的時間，與容器作為將整疊卡片。

類的宣告

以下是宣告的java.awt.CardLayout類：

public class CardLayout
   extends Object
      implements LayoutManager2, Serializable

類別建構函式

S.N. 建構函式與說明
1 CardLayout() 
Creates a new card layout with gaps of size zero.
2 CardLayout(int hgap, int vgap) 
Creates a new card layout with the specified horizontal and vertical gaps.

類方法

S.N. 方法和說明
1 void addLayoutComponent(Component comp, Object constraints) 
Adds the specified component to this card layout's internal table of names.
2 void addLayoutComponent(String name, Component comp) 
If the layout manager uses a per-component string, adds the component comp to the layout, associating it with the string specified by name.
3 void first(Container parent) 
Flips to the first card of the container.
4 int getHgap() 
Gets the horizontal gap between components.
5 float getLayoutAlignmentX(Container parent) 
Returns the alignment along the x axis.
6 float getLayoutAlignmentY(Container parent) 
Returns the alignment along the y axis.
7 int getVgap() 
Gets the vertical gap between components.
8 void invalidateLayout(Container target) 
Invalidates the layout, indicating that if the layout manager has cached information it should be discarded.
9 void last(Container parent) 
Flips to the last card of the container.
10 void layoutContainer(Container parent) 
Lays out the specified container using this card layout.
11 Dimension maximumLayoutSize(Container target) 
Returns the maximum dimensions for this layout given the components in the specified target container.
12 Dimension minimumLayoutSize(Container parent) 
Calculates the minimum size for the specified panel.
13 void next(Container parent) 
Flips to the next card of the specified container.
14 Dimension preferredLayoutSize(Container parent) 
Determines the preferred size of the container argument using this card layout.
15 void previous(Container parent) 
Flips to the previous card of the specified container.
16 void removeLayoutComponent(Component comp) 
Removes the specified component from the layout.
17 void setHgap(int hgap) 
Sets the horizontal gap between components.
18 void setVgap(int vgap) 
Sets the vertical gap between components.
19 void show(Container parent, String name) 
Flips to the component that was added to this layout with the specified name, using addLayoutComponent.
20 String toString() 
Returns a string representation of the state of this card layout.

繼承的方法

這個類繼承的方法從以下類：

  • java.lang.Object

CardLayout 範例

選擇使用任何編輯器建立以下java程式 D:/ > AWT > com > yiibai > gui >

AwtLayoutDemo.java 
package com.yiibai.gui;

import java.awt.*;
import java.awt.event.*;

public class AwtLayoutDemo {
   private Frame mainFrame;
   private Label headerLabel;
   private Label statusLabel;
   private Panel controlPanel;
   private Label msglabel;

   public AwtLayoutDemo(){
      prepareGUI();
   }

   public static void main(String[] args){
      AwtLayoutDemo  awtLayoutDemo = new AwtLayoutDemo();  
      awtLayoutDemo.showCardLayoutDemo();       
   }
      
   private void prepareGUI(){
      mainFrame = new Frame("Java AWT 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 Label();
      headerLabel.setAlignment(Label.CENTER);
      statusLabel = new Label();        
      statusLabel.setAlignment(Label.CENTER);
      statusLabel.setSize(350,100);

      msglabel = new Label();
      msglabel.setAlignment(Label.CENTER);
      msglabel.setText("Welcome to TutorialsPoint AWT Tutorial.");

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

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

   private void showCardLayoutDemo(){
      headerLabel.setText("Layout in action: CardLayout");      

      final Panel panel = new Panel();
      panel.setBackground(Color.CYAN);
      panel.setSize(300,300);

      CardLayout layout = new CardLayout();
      layout.setHgap(10);
      layout.setVgap(10);
      panel.setLayout(layout);        

      Panel buttonPanel = new Panel(new FlowLayout());

      buttonPanel.add(new Button("OK"));
      buttonPanel.add(new Button("Cancel"));    

      Panel textBoxPanel = new Panel(new FlowLayout());

      textBoxPanel.add(new Label("Name:"));
      textBoxPanel.add(new TextField(20));

      panel.add("Button", buttonPanel);
      panel.add("Text", textBoxPanel);

      Choice choice = new Choice();
      choice.add("Button");
      choice.add("Text");

      choice.addItemListener(new ItemListener() {
         public void itemStateChanged(ItemEvent e) {
            CardLayout cardLayout = (CardLayout)(panel.getLayout());
            cardLayout.show(panel, (String)e.getItem());
         }
      });
      controlPanel.add(choice);
      controlPanel.add(panel);

      mainFrame.setVisible(true);  
   }
}

編譯程式，使用命令提示字元。進入到D:/> AWT，然後鍵入以下命令。

D:AWT>javac comyiibaiguiAwtlayoutDemo.java

如果沒有錯誤出現，這意味著編譯成功。使用下面的命令來執行程式。

D:AWT>java com.yiibai.gui.AwtlayoutDemo

驗證下面的輸出

AWT CardLayout