/ **这个java类作为销售模拟器工作，我很难使用Total和enter按钮，问题是Total和Enter按钮，我无法理解为什么这些按钮不起作用!! * /
//从Java库导入应用程序
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.text.*;
// Starting CashRegister class
public class CashRegister extends JFrame
{
//initiate value
double subtotal = 0.0; // stores subtotal of items purchased
// JLabel and JTextField to enter amount
private JLabel amountJLabel;
private JTextField amountJTextField;
// JButtons to enter numbers in amountJTextField
private JButton oneJButton;
private JButton twoJButton;
private JButton threeJButton;
private JButton fourJButton;
private JButton fiveJButton;
private JButton sixJButton;
private JButton sevenJButton;
private JButton eightJButton;
private JButton nineJButton;
private JButton zeroJButton;
private JButton pointJButton;
// JButton to add value in amountJTextField to subtotal
private JButton enterJButton;
// JButton to determine tax and calculate final total
private JButton totalJButton;
// JButton to delete value displayed in amountJTextField
private JButton deleteJButton;
// JButton to clear results
private JButton clearJButton;
// JLabel and JTextField to display subtotal
private JLabel subtotalJLabel;
private JTextField subtotalJTextField;
// JLabel and JTextField to display tax
private JLabel taxJLabel;
private JTextField taxJTextField;
// JLabel and JTextField to display final total
private JLabel totalJLabel;
private JTextField totalJTextField;
// DecimalFormat to format dollar amounts
private DecimalFormat dollars = new DecimalFormat( "$0.00" );
// no-argument constructor
public CashRegister()
{
createUserInterface();
}
// create and position GUI components; register event handlers
private void createUserInterface()
{
// get content pane for attaching GUI components
Container contentPane = getContentPane();
// enable explicit positioning of GUI components
contentPane.setLayout( null );
// set up amountJLabel
amountJLabel = new JLabel();
amountJLabel.setBounds( 20, 20, 15, 20 );
amountJLabel.setText( "$" );
contentPane.add( amountJLabel );
// set up amountJTextField
amountJTextField = new JTextField();
amountJTextField.setBounds( 40, 20, 260, 20 );
contentPane.add( amountJTextField );
// set up oneJButton
oneJButton = new JButton();
oneJButton.setBounds( 55, 70, 45, 20 );
oneJButton.setText( "1" );
contentPane.add( oneJButton );
oneJButton.addActionListener(
new ActionListener() // anonymous inner class
{
// event handler called when oneJButton is pressed
public void actionPerformed( ActionEvent event )
{
oneJButtonActionPerformed( event );
}
}
// end anonymous inner class
);
// end call to addActionListener
// set up twoJButton
twoJButton = new JButton();
twoJButton.setBounds( 100, 70, 45, 20 );
twoJButton.setText( "2" );
contentPane.add( twoJButton );
twoJButton.addActionListener(
new ActionListener() // anonymous inner class
{
// event handler called when twoJButton is pressed
public void actionPerformed( ActionEvent event )
{
twoJButtonActionPerformed( event );
}
}
// end anonymous inner class
);
// end call to addActionListener
// set up threeJButton
threeJButton = new JButton();
threeJButton.setBounds( 145, 70, 45, 20 );
threeJButton.setText( "3" );
contentPane.add( threeJButton );
threeJButton.addActionListener(
new ActionListener() // anonymous inner class
{
// event handler called when threeJButton is pressed
public void actionPerformed( ActionEvent event )
{
threeJButtonActionPerformed( event );
}
}
// end anonymous inner class
);
// end call to addActionListener
// set up fourJButton
fourJButton = new JButton();
fourJButton.setBounds( 55, 90, 45, 20 );
fourJButton.setText( "4" );
contentPane.add( fourJButton );
fourJButton.addActionListener(
new ActionListener() // anonymous inner class
{
// event handler called when fourJButton is pressed
public void actionPerformed( ActionEvent event )
{
fourJButtonActionPerformed( event );
}
}
// end anonymous inner class
);
// end call to addActionListener
// set up fiveJButton
fiveJButton = new JButton();
fiveJButton.setBounds( 100, 90, 45, 20 );
fiveJButton.setText( "5" );
contentPane.add( fiveJButton );
fiveJButton.addActionListener(
new ActionListener() // anonymous inner class
{
// event handler called when fiveJButton is pressed
public void actionPerformed( ActionEvent event )
{
fiveJButtonActionPerformed( event );
}
}
// end anonymous inner class
);
// end call to addActionListener
// set up sixJButton
sixJButton = new JButton();
sixJButton.setBounds( 145, 90, 45, 20 );
sixJButton.setText( "6" );
contentPane.add( sixJButton );
sixJButton.addActionListener(
new ActionListener() // anonymous inner class
{
// event handler called when sixJButton is pressed
public void actionPerformed( ActionEvent event )
{
sixJButtonActionPerformed( event );
}
}
// end anonymous inner class
);
// end call to addActionListener
// set up sevenJButton
sevenJButton = new JButton();
sevenJButton.setBounds( 55, 110, 45, 20 );
sevenJButton.setText( "7" );
contentPane.add( sevenJButton );
sevenJButton.addActionListener(
new ActionListener() // anonymous inner class
{
// event handler called when sevenJButton is pressed
public void actionPerformed( ActionEvent event )
{
sevenJButtonActionPerformed( event );
}
}
// end anonymous inner class
);
// end call to addActionListener
// set up eightJButton
eightJButton = new JButton();
eightJButton.setBounds( 100, 110, 45, 20 );
eightJButton.setText( "8" );
contentPane.add( eightJButton );
eightJButton.addActionListener(
new ActionListener() // anonymous inner class
{
// event handler called when eightJButton is pressed
public void actionPerformed( ActionEvent event )
{
eightJButtonActionPerformed( event );
}
} // end anonymous inner class
);
// end call to addActionListener
// set up nineJButton
nineJButton = new JButton();
nineJButton.setBounds( 145, 110, 45, 20 );
nineJButton.setText( "9" );
contentPane.add( nineJButton );
nineJButton.addActionListener(
new ActionListener() // anonymous inner class
{
// event handler called when nineJButton is pressed
public void actionPerformed( ActionEvent event )
{
nineJButtonActionPerformed( event );
}
}
// end anonymous inner class
); // end call to addActionListener
// set up zeroJButton
zeroJButton = new JButton();
zeroJButton.setBounds( 100, 130, 45, 20 );
zeroJButton.setText( "0" );
contentPane.add( zeroJButton );
zeroJButton.addActionListener(
new ActionListener() // anonymous inner class
{
// event handler called when zeroJButton is pressed
public void actionPerformed( ActionEvent event )
{
zeroJButtonActionPerformed( event );
}
}
// end anonymous inner class
);
// end call to addActionListener
// set up pointJButton
pointJButton = new JButton();
pointJButton.setBounds( 145, 130, 45, 20 );
pointJButton.setText( "." );
contentPane.add( pointJButton );
pointJButton.addActionListener(
new ActionListener() // anonymous inner class
{
// event handler called when pointJButton is pressed
public void actionPerformed( ActionEvent event )
{
pointJButtonActionPerformed( event );
}
}
// end anonymous inner class
);
// end call to addActionListener
// set up enterJButton
enterJButton = new JButton();
enterJButton.setBounds( 205, 70, 70, 20 );
enterJButton.setText( "Enter" );
contentPane.add( enterJButton );
enterJButton.addActionListener(
new ActionListener() // anonymous inner class
{
// event handler called when enterJButton is pressed
public void actionPerformed( ActionEvent event )
{
enterJButtonActionPerformed( event );
}
} // end anonymous inner class
);
// end call to addActionListener
// set up totalJButton
totalJButton = new JButton();
totalJButton.setBounds( 205, 90, 70, 20 );
totalJButton.setText( "Total" );
contentPane.add( totalJButton );
totalJButton.addActionListener(
new ActionListener() // anonymous inner class
{
// event handler called when totalJButton is pressed
public void actionPerformed( ActionEvent event )
{
totalJButtonActionPerformed( event );
}
}
// end anonymous inner class
);
// end call to addActionListener
// set up deleteJButton
deleteJButton = new JButton();
deleteJButton.setBounds( 205, 110, 70, 20 );
deleteJButton.setText( "Delete" );
contentPane.add( deleteJButton );
deleteJButton.addActionListener(
new ActionListener() // anonymous inner class
{
// event handler called when deleteJButton is pressed
public void actionPerformed( ActionEvent event )
{
deleteJButtonActionPerformed( event );
}
}
// end anonymous inner class
);
// end call to addActionListener
// set up clearJButton
clearJButton = new JButton();
clearJButton.setBounds( 205, 130, 70, 20 );
clearJButton.setText( "Clear" );
contentPane.add( clearJButton );
clearJButton.addActionListener(
new ActionListener() // anonymous inner class
{
// event handler called when clearJButton is pressed
public void actionPerformed( ActionEvent event )
{
clearJButtonActionPerformed( event );
}
}
// end anonymous inner class
);
// end call to addActionListener
// set up subtotalJLabel;
subtotalJLabel = new JLabel();
subtotalJLabel.setBounds( 20, 180, 90, 20 );
subtotalJLabel.setText( "Subtotal:" );
contentPane.add( subtotalJLabel );
// set up subtotalJTextField
subtotalJTextField = new JTextField();
subtotalJTextField.setBounds( 160, 180, 140, 20 );
subtotalJTextField.setHorizontalAlignment( JTextField.RIGHT );
subtotalJTextField.setEditable( false );
subtotalJTextField.setText( "$0.00" );
contentPane.add( subtotalJTextField );
// set up taxJLabel
taxJLabel = new JLabel();
taxJLabel.setBounds( 20, 220, 60, 20 );
taxJLabel.setText( "Tax:" );
contentPane.add( taxJLabel );
// set up taxJTextField
taxJTextField = new JTextField();
taxJTextField.setBounds( 160, 220, 140, 20 );
taxJTextField.setHorizontalAlignment( JTextField.RIGHT );
taxJTextField.setEditable( false );
taxJTextField.setText( "$0.00" );
contentPane.add( taxJTextField );
// set up totalJLabel
totalJLabel = new JLabel();
totalJLabel.setBounds( 20, 260, 70, 20 );
totalJLabel.setText( "Total:" );
contentPane.add( totalJLabel );
// set up totalJTextField
totalJTextField = new JTextField();
totalJTextField.setBounds( 160, 260, 140, 20 );
totalJTextField.setHorizontalAlignment( JTextField.RIGHT );
totalJTextField.setEditable( false );
totalJTextField.setText( "$0.00" );
contentPane.add( totalJTextField );
// set properties of application's window
setTitle( "Cash Register" ); // set window title
setSize( 345, 330 ); // set window size
setVisible( true ); // display window
}
// end method createUserInterface
// append "0" to the amount in amountJTextField
private void zeroJButtonActionPerformed( ActionEvent event )
{
amountJTextField.setText( amountJTextField.getText() + "0" );
}
// end method zeroJButtonActionPerformed
// append "1" to the amount in amountJTextField
private void oneJButtonActionPerformed( ActionEvent event )
{
amountJTextField.setText( amountJTextField.getText() + "1" );
}
// end method oneJButtonActionPerformed
// append "2" to the amount in amountJTextField
private void twoJButtonActionPerformed( ActionEvent event )
{
amountJTextField.setText( amountJTextField.getText() + "2" );
} // end method twoJButtonActionPerformed
// append "3" to the amount in amountJTextField
private void threeJButtonActionPerformed( ActionEvent event )
{
amountJTextField.setText( amountJTextField.getText() + "3" );
}
// end method threeJButtonActionPerformed
// append "4" to the amount in amountJTextField
private void fourJButtonActionPerformed( ActionEvent event )
{
amountJTextField.setText( amountJTextField.getText() + "4" );
}
// end method fourJButtonActionPerformed
// append "5" to the amount in amountJTextField
private void fiveJButtonActionPerformed( ActionEvent event )
{
amountJTextField.setText( amountJTextField.getText() + "5" );
} // end method fiveJButtonActionPerformed
// append "6" to the amount in amountJTextField
private void sixJButtonActionPerformed( ActionEvent event )
{
amountJTextField.setText( amountJTextField.getText() + "6" );
}
// end method sixJButtonActionPerformed
// append "7" to the amount in amountJTextField
private void sevenJButtonActionPerformed( ActionEvent event )
{
amountJTextField.setText( amountJTextField.getText() + "7" );
} // end method sevenJButtonActionPerformed
// append "8" to the amount in amountJTextField
private void eightJButtonActionPerformed( ActionEvent event )
{
amountJTextField.setText( amountJTextField.getText() + "8" );
} // end method eightJButtonActionPerformed
// append "9" to the amount in amountJTextField
private void nineJButtonActionPerformed( ActionEvent event )
{
amountJTextField.setText( amountJTextField.getText() + "9" );
}
// end method nineJButtonActionPerformed
// append "." to the amount in amountJTextField
private void pointJButtonActionPerformed( ActionEvent event )
{
amountJTextField.setText( amountJTextField.getText() + "." );
} // end method pointJButtonActionPerformed
// calculate and display subtotal
private void enterJButtonActionPerformed( ActionEvent event )
{
}
// end method enterJButtonActionPerformed
// calculate and display total after taxes
private void totalJButtonActionPerformed( ActionEvent event )
{
}
// end method totalJButtonActionPerformed
// clear current amount displayed in amountJTextField
private void deleteJButtonActionPerformed( ActionEvent event )
{
amountJTextField.setText( "" );
}
// end method deleteJButtonActionPerformed
// clear all results
private void clearJButtonActionPerformed( ActionEvent event )
{
amountJTextField.setText( "" );
subtotalJTextField.setText( "$0.00" );
taxJTextField.setText( "$0.00" );
totalJTextField.setText( "$0.00" );
subtotal = 0.0; // reset subtotal to 0.0
}
// end method clearJButtonActionPerformed
// main method
public static void main( String[] args )
{
CashRegister application = new CashRegister();
application.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
}
// end method main
}/** the end of the program*/
答案 0 :(得分：0)
我认为这是显示ActionListener的最简单方法。 如果您了解此基础知识，则可以修复自己的代码：）
package actionlistenerexample;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class ActionListenerExample extends JFrame implements ActionListener{
JPanel panel = new JPanel();
JButton button1;
JButton button2;
public ActionListenerExample(){
setVisible(true);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
add(panel);
button1 = new JButton("Button1");
button1.addActionListener(this);
button2 = new JButton("Button2");
button2.addActionListener(this);
panel.add(button1);
panel.add(button2);
pack();
}
public static void main(String[] args) {
JFrame jf = new ActionListenerExample();
}
@Override
public void actionPerformed(ActionEvent event){
if(event.getSource() == button1){
System.out.println("Button1 clicked");
}
if(event.getSource() == button2){
System.out.println("Button2 clicked");
}
}
}
答案 1 :(得分：0)
因为您没有在此处执行任何操作，
new ActionListener() // anonymous inner class
{
// event handler called when totalJButton is pressed
public void actionPerformed( ActionEvent event )
{
totalJButtonActionPerformed( event );
}
}
调用totalJButtonActionPerformed( ActionEvent event )方法
private void totalJButtonActionPerformed( ActionEvent event )
{
//write some code here to perform some action
}