calculator.java

来自「32个java程序源代码」· Java 代码 · 共 225 行

// Exercise 2.11
// Create GUI calculator
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.border.*;

public class Calculator extends JFrame
{
   private JButton oneJButton, twoJButton, threeJButton,
      fourJButton, fiveJButton, sixJButton, sevenJButton, 
      eightJButton, nineJButton, zeroJButton, doubleZeroJButton, 
      plusJButton, minusJButton, timesJButton, divideJButton, 
      equalsJButton, decimalJButton, clearJButton, clearAllJButton, 
      offJButton;
   private JTextField displayJTextField;
   private JPanel numberJPanel, operationJPanel, clearJPanel;
   
   // no-argument constructor
   public Calculator()
   {
      createUserInterface();
   }
   
   // create and position GUI components; register event handlers
   private void createUserInterface()
   {
      // get content pane and set layout to null
      Container contentPane = getContentPane();
      contentPane.setLayout( null );
      
      // set up displayJTextField
      displayJTextField = new JTextField();
      displayJTextField.setText( "0" );
      displayJTextField.setBounds( 16, 16, 480, 24 );
      displayJTextField.setHorizontalAlignment( JTextField.RIGHT );
      contentPane.add( displayJTextField );
      
      // set up numberJPanel
      numberJPanel = new JPanel();
      numberJPanel.setLayout( null );
      numberJPanel.setBounds( 16, 62, 176, 224 );
      numberJPanel.setBorder( 
         new BevelBorder( BevelBorder.LOWERED ) );
      contentPane.add( numberJPanel );
            
      // set up oneJButton
      oneJButton = new JButton();
      oneJButton.setText( "1" );
      oneJButton.setBounds( 16, 16, 48, 48 );
      numberJPanel.add( oneJButton );
      
      // set up two JButton
      twoJButton = new JButton();
      twoJButton.setText( "2" );
      twoJButton.setBounds( 64, 16, 48, 48 );
      numberJPanel.add( twoJButton );
      
      // set up threeJButton
      threeJButton = new JButton();
      threeJButton.setText( "3" );
      threeJButton.setBounds( 112, 16, 48, 48 );
      numberJPanel.add( threeJButton );
      
      // set up fourJButton
      fourJButton = new JButton();
      fourJButton.setText( "4" );
      fourJButton.setBounds( 16, 64, 48, 48 );
      numberJPanel.add( fourJButton );
      
      // set up fiveJButton
      fiveJButton = new JButton();
      fiveJButton.setText( "5" );
      fiveJButton.setBounds( 64, 64, 48, 48 );
      numberJPanel.add( fiveJButton );
      
      // set up sixJButton
      sixJButton = new JButton();
      sixJButton.setText( "6" );
      sixJButton.setBounds( 112, 64, 48, 48 );
      numberJPanel.add( sixJButton );
      
      // set up sevenJButton
      sevenJButton = new JButton();
      sevenJButton.setText( "7" );
      sevenJButton.setBounds( 16, 112, 48, 48 );
      numberJPanel.add( sevenJButton );
      
      // set up eightJButton
      eightJButton = new JButton();
      eightJButton.setText( "8" );
      eightJButton.setBounds( 64, 112, 48, 48 );
      numberJPanel.add( eightJButton );
      
      // set up nineJButton
      nineJButton = new JButton();
      nineJButton.setText( "9" );
      nineJButton.setBounds( 112, 112, 48, 48 );
      numberJPanel.add( nineJButton );
      
      // set up zeroJButton
      zeroJButton = new JButton();
      zeroJButton.setText( "0" );
      zeroJButton.setBounds( 16, 160, 48, 48 );
      numberJPanel.add( zeroJButton );
            
      // set up doubleZeroJButton
      doubleZeroJButton = new JButton();
      doubleZeroJButton.setText( "00" );
      doubleZeroJButton.setBounds( 64, 160, 96, 48 );
      numberJPanel.add( doubleZeroJButton );

      // set up operationJPanel
      operationJPanel = new JPanel();
      operationJPanel.setLayout( null );
      operationJPanel.setBounds( 224, 62, 144, 224 );
      operationJPanel.setBorder( 
         new BevelBorder( BevelBorder.LOWERED ) );
      contentPane.add( operationJPanel );
      
      // set up plusJButton
      plusJButton = new JButton();
      plusJButton.setFont( 
         new Font( "SansSerif", Font.PLAIN, 18 ) );
      operationJPanel.add( plusJButton );
            
      // set up minusJButton
      minusJButton = new JButton();
      minusJButton.setText( "-" );
      minusJButton.setBounds( 80, 16, 48, 48 );
      minusJButton.setFont( 
         new Font( "SansSerif", Font.PLAIN, 18 ) );
      operationJPanel.add( minusJButton );
      
      // set up timesJButton
      timesJButton = new JButton();
      timesJButton.setText( "*" );
      timesJButton.setBounds( 80, 64, 48, 48 );
      timesJButton.setFont( 
         new Font( "SansSerif", Font.PLAIN, 18 ) );
      operationJPanel.add( timesJButton );
      
      // set up divideJButton
      divideJButton = new JButton();
      divideJButton.setText( "/" );
      divideJButton.setBounds( 80, 112, 48, 48 );
      divideJButton.setFont( 
         new Font( "SansSerif", Font.PLAIN, 18 ) );
      operationJPanel.add( divideJButton );
      
      // set up equalsJButton
      equalsJButton = new JButton();
      equalsJButton.setText( "=" );
      equalsJButton.setBounds( 80, 160, 48, 48 );
      equalsJButton.setFont( 
         new Font( "SansSerif", Font.PLAIN, 18 ) );
      operationJPanel.add( equalsJButton );
      
      // set up decimalJButton
      decimalJButton = new JButton();
      decimalJButton.setText( "." );
      decimalJButton.setBounds( 16, 160, 48, 48 );
      decimalJButton.setFont( 
         new Font( "SansSerif", Font.PLAIN, 18 ) );
      operationJPanel.add( decimalJButton );
            
      // set up clearJPanel
      clearJPanel = new JPanel();
      clearJPanel.setLayout( null );
      clearJPanel.setBounds( 400, 62, 96, 144 );
      clearJPanel.setBorder( 
         new BevelBorder( BevelBorder.LOWERED ) );
      contentPane.add( clearJPanel );

      // set up clearJButton
      clearJButton = new JButton();
      clearJButton.setText( "C" );
      clearJButton.setBounds( 16, 16, 64, 48 );
      clearJPanel.add( clearJButton );
      
      // set up clearAllJButton
      clearAllJButton = new JButton();
      clearAllJButton.setText( "C/A" );
      clearAllJButton.setBounds( 16, 80, 64, 48 );
      clearJPanel.add( clearAllJButton );
      
      // set up offJButton
      offJButton = new JButton();
      offJButton.setText( "OFF" );
      offJButton.setBounds( 400, 238, 96, 48 );
      contentPane.add( offJButton );
            
      // set properties of application's window
      setTitle( "Calculator" ); // set title bar text
      setSize( 520, 330 );      // set window size
      setVisible( true );       // display window

   } // end method createUserInterface

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

   } // end method main

} // end class Calculator


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