jcheckboxdemo.java

精通Java核心技术源代码

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
  
public class JCheckBoxDemo extends JFrame 
{
      static String bold = "Bold";
      static String italic = "Italic";
      
      JTextField textField;
      JCheckBox boldBox,italicBox;
  
      public JCheckBoxDemo() 
      {
          super( "JCheckBoxDemo" );
		
          // 获取content pane并设置布局管理器
          Container container = getContentPane();
          container.setLayout( new FlowLayout() );
  		
          // 创建一个文本框并设置其字体
          textField = new JTextField( "Welcome to Java World!",20 );
          textField.setFont( new Font( "Serif",Font.PLAIN,14 ) );
          container.add( textField );
		
          // 创建选择框
          boldBox = new JCheckBox( bold );
          container.add( boldBox );
         
          italicBox = new JCheckBox( italic );
          container.add( italicBox );
            
          // 为选择框注册事件处理器
          EventHandler handler = new EventHandler();
          boldBox.addItemListener( handler );
          italicBox.addItemListener( handler );
        
          setSize( 260,100 );
          setVisible( true );
      }
      
      // 获取content pane并设置布局管理器
      private class EventHandler implements ItemListener
      {
          private int boldSelected = Font.PLAIN;
          private int italicSelected = Font.PLAIN;
      	
      	   // 处理选择框事件
      	   public void itemStateChanged( ItemEvent event )
      	   {
      			// 判断boldBox是否被选中
      			if ( event.getSource() == boldBox ) 
      		   		if ( event.getStateChange() == ItemEvent.SELECTED )
      		      		boldSelected = Font.BOLD;
      		   		else boldSelected = Font.PLAIN;
    		
    			// 判断italicBox是否被选中
    			if ( event.getSource() == italicBox )
    	   			if ( event.getStateChange() == ItemEvent.SELECTED )
    	      			italicSelected = Font.ITALIC;
    	   			else italicSelected = Font.PLAIN;
    		
    			// 设置文本框字体
    			textField.setFont( new Font( "Serif",boldSelected + italicSelected,14 ) );
      	   }
      }
      public static void main(String args[]) 
      {
           JCheckBoxDemo checkBoxDemo = new JCheckBoxDemo();
           checkBoxDemo.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
      }
  }