Swing建立垂直滾軸範例

下面的範例展示了如何在Java Swing應用程式中使用垂直滾軸。

使用以下API -

• JSlider(orientation, min, max, value) - 在方向設定垂直方向時建立滾軸。
• JSlider.getValue() - 獲取滾軸的當前值。

範例

package com.yiibai.swingdemo;

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

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

   public SwingTester(){
      prepareGUI();
   }
   public static void main(String[] args){
       SwingTester  swingControlDemo = new SwingTester();      
      swingControlDemo.showSliderDemo();
   }
   private void prepareGUI(){
      mainFrame = new JFrame("Swing建立垂直滾軸範例");
      mainFrame.setSize(400,700);
      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);

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

      mainFrame.add(headerLabel);
      mainFrame.add(controlPanel);
      mainFrame.add(statusLabel);
      mainFrame.setVisible(true);  
   }
   private void showSliderDemo(){
      headerLabel.setText("Control in action: JSlider"); 
      JSlider slider = new JSlider(JSlider.VERTICAL,0,100,10);

      slider.addChangeListener(new ChangeListener() {
         public void stateChanged(ChangeEvent e) {
            statusLabel.setText("當前值 : " + ((JSlider)e.getSource()).getValue());
         }
      });
      controlPanel.add(slider);      
      mainFrame.setVisible(true);     
   } 
}

執行上面範例程式碼，得到以下結果：