counter.java

来自「32个java程序源代码」· Java 代码 · 共 91 行

// Exercise 4.12: Counter.java
// This application displays a number which increments each time the
// Count JButton is pressed.
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class Counter extends JFrame
{
   // JTextField for displaying total count
   private JTextField countJTextField; 

   // JButton to initiate adding one to numeric value in JTextField
   private JButton countJButton;       
   
   // no-argument constructor
   public Counter() 
   {
      createUserInterface();
   }
   
   // create and position GUI components; register event handler
   private void createUserInterface()
   {
      // get content pane and set layout to null
      Container contentPane = getContentPane();
      contentPane.setLayout( null );
      
      // set up countJTextField
      countJTextField = new JTextField();
      countJTextField.setBounds( 24, 24, 88, 21 );
      countJTextField.setEditable( false );
      contentPane.add( countJTextField );
      
      // set up countJButton
      countJButton = new JButton();
      countJButton.setBounds( 24, 64, 88, 24 );
      contentPane.add( countJButton );
      countJButton.addActionListener(

         new ActionListener() // anonymous inner class
         {
            // event handler called when countJButton is pressed
            public void actionPerformed( ActionEvent event )
            {
               countJButtonActionPerformed( event );
            }

         } // end anonymous inner class

      ); // end call to addActionListener
      
      // set properties of application抯 window
      setTitle( "Counter" ); // set title bar text
      setSize( 144, 136 );   // set window size
      setVisible( true );    // display window

   } // end method createUserInterface

   // increment the count each time countJButton is pressed
   private void countJButtonActionPerformed( ActionEvent event )
   {

   } // end method countJButtonActionPerformed

   // main method
   public static void main( String[] args ) 
   {
      Counter application = new Counter();
      application.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );

   } // end method main

} // end class Counter


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