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我正在製作收銀機程序。當我點擊Checkout按鈕時，輸入對話框會出現，輸入，然後關閉/停止while循環，而不輸入任何內容並確定或按取消。之後它會顯示數據。當我再次單擊Checkout時，輸入對話框將不會顯示，以便您輸入更多內容，並且必須重新運行java中的項目才能再次使用它。我怎樣才能改變它到它結束並顯示數據的地方，再次按結賬按鈕會再次按照第一次按下同樣的操作？循環GUI按鈕在第二次按下時不起作用
import java.text.NumberFormat;
import javax.swing.JOptionPane;
public class CashRegisterGUI extends javax.swing.JFrame {
NumberFormat nF = NumberFormat.getCurrencyInstance();
private double purchase;
private int numItems;
boolean keepShopping = true;
/**
* Creates new form CashRegisterGUI
*/
public CashRegisterGUI() {
initComponents();
purchase=0;
numItems=0;
}
// set method to add item price
public void recordPurchase (double itemPrice)
{ purchase = purchase + itemPrice ;
numItems++;}
// get method to get purchase total
public double getPurchase() { return purchase ; }
// get method to get number of items
public int getItems() { return numItems; }
/**
* This method is called from within the constructor to initialize the form.
* WARNING: Do NOT modify this code. The content of this method is always
* regenerated by the Form Editor.
*/
@SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
jLabel1 = new javax.swing.JLabel();
txtPrice = new javax.swing.JTextField();
jLabel2 = new javax.swing.JLabel();
txtSub = new javax.swing.JTextField();
jLabel3 = new javax.swing.JLabel();
txtItems = new javax.swing.JTextField();
jLabel4 = new javax.swing.JLabel();
txtTax = new javax.swing.JTextField();
jLabel5 = new javax.swing.JLabel();
txtTotal = new javax.swing.JTextField();
bttnCheckout = new javax.swing.JButton();
bttnReset = new javax.swing.JButton();
bttnExit = new javax.swing.JButton();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
setTitle("Dylans Grocery Calculator");
jLabel1.setFont(new java.awt.Font("Tahoma", 0, 14)); // NOI18N
jLabel1.setText("Item Price");
jLabel2.setFont(new java.awt.Font("Tahoma", 0, 14)); // NOI18N
jLabel2.setText("Sub Total");
jLabel3.setFont(new java.awt.Font("Tahoma", 0, 14)); // NOI18N
jLabel3.setText("Number of Items");
jLabel4.setFont(new java.awt.Font("Tahoma", 0, 14)); // NOI18N
jLabel4.setText("Sales Tax");
jLabel5.setText("Total Sale");
bttnCheckout.setText("Checkout");
bttnCheckout.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
bttnCheckoutActionPerformed(evt);
}
});
bttnReset.setText("Reset");
bttnReset.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
bttnResetActionPerformed(evt);
}
});
bttnExit.setText("Exit");
bttnExit.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
bttnExitActionPerformed(evt);
}
});
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
.addGroup(layout.createSequentialGroup()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(13, 13, 13)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jLabel1)
.addComponent(jLabel2)
.addComponent(jLabel3)
.addComponent(jLabel4)
.addComponent(jLabel5))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
.addComponent(txtTotal, javax.swing.GroupLayout.DEFAULT_SIZE, 100, Short.MAX_VALUE)
.addComponent(txtTax)
.addComponent(txtItems)
.addComponent(txtSub)
.addComponent(txtPrice)))
.addGroup(layout.createSequentialGroup()
.addGap(0, 12, Short.MAX_VALUE)
.addComponent(bttnCheckout, javax.swing.GroupLayout.PREFERRED_SIZE, 85, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(18, 18, 18)
.addComponent(bttnReset, javax.swing.GroupLayout.PREFERRED_SIZE, 85, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addComponent(bttnExit, javax.swing.GroupLayout.PREFERRED_SIZE, 76, javax.swing.GroupLayout.PREFERRED_SIZE)))
.addContainerGap())
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jLabel1)
.addComponent(txtPrice, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGap(31, 31, 31)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jLabel2)
.addComponent(txtSub, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGap(29, 29, 29)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jLabel3)
.addComponent(txtItems, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGap(28, 28, 28)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jLabel4)
.addComponent(txtTax, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGap(31, 31, 31)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jLabel5)
.addComponent(txtTotal, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 51, Short.MAX_VALUE)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(bttnCheckout)
.addComponent(bttnReset)
.addComponent(bttnExit))
.addContainerGap())
);
pack();
}// </editor-fold>
private void bttnExitActionPerformed(java.awt.event.ActionEvent evt) {
//exit system upon exit bttnexit press by user
System.exit(0);
}
private void bttnResetActionPerformed(java.awt.event.ActionEvent evt) {
//set text fields back to empty
txtPrice.setText("");
txtSub.setText("");
txtTax.setText("");
txtTotal.setText("");
txtItems.setText("");
}
private void bttnCheckoutActionPerformed(java.awt.event.ActionEvent evt) {
//checkout button
double itemPrice;
double subTotal;
double salesTax;
double totalSale;
//Intialiaze subTotal
subTotal = 0;
while (keepShopping){ //loop if true
try{
String newItemPrice = JOptionPane.showInputDialog(this,
"Enter item price:", "Enter price",
JOptionPane.PLAIN_MESSAGE);
if ((newItemPrice !=null) && (newItemPrice.length() >0)) //check input
{
itemPrice = Double.parseDouble(newItemPrice);
subTotal = itemPrice + subTotal; //get subtotal
txtPrice.setText(nF.format(itemPrice)); //show item price
txtSub.setText(nF.format(subTotal)); //show subtotal
numItems ++; //count items
txtItems.setText(Integer.toString(numItems)); //show items
}
else
{
keepShopping = false; //end loop
salesTax = .065 * subTotal; //get salestax
txtTax.setText(nF.format(salesTax)); //show salestax
totalSale = subTotal + salesTax; //get total
txtTotal.setText(nF.format(totalSale)); //show total
}
}
catch(NumberFormatException e) // catches bad data
{
JOptionPane.showMessageDialog(this,
"Your input must be numeric!",
"Bad data!", JOptionPane.ERROR_MESSAGE);
}
}
}
/**
* @param args the command line arguments
*/
public static void main(String args[]) {
/* Set the Nimbus look and feel */
//<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
/* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
* For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html
*/
try {
for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
if ("Nimbus".equals(info.getName())) {
javax.swing.UIManager.setLookAndFeel(info.getClassName());
break;
}
}
} catch (ClassNotFoundException ex) {
java.util.logging.Logger.getLogger(CashRegisterGUI.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(CashRegisterGUI.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(CashRegisterGUI.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(CashRegisterGUI.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
//</editor-fold>
/* Create and display the form */
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
CashRegisterGUI frame = new CashRegisterGUI();
frame.setVisible(true);
frame.setLocationRelativeTo(null);
}
});
}
// Variables declaration - do not modify
private javax.swing.JButton bttnCheckout;
private javax.swing.JButton bttnExit;
private javax.swing.JButton bttnReset;
private javax.swing.JLabel jLabel1;
private javax.swing.JLabel jLabel2;
private javax.swing.JLabel jLabel3;
private javax.swing.JLabel jLabel4;
private javax.swing.JLabel jLabel5;
private javax.swing.JTextField txtItems;
private javax.swing.JTextField txtPrice;
private javax.swing.JTextField txtSub;
private javax.swing.JTextField txtTax;
private javax.swing.JTextField txtTotal;
// End of variables declaration
}
我也有一個重置按鈕，只有.setText（「」）;清除文本框。如果這將是一個更簡單的地方來實現這一點。
謝謝您的時間！
我看到你把'keepShopping'分配給'false' ...........但你是否曾經將它重新分配給'true'？我不這麼認爲，所以在'while（keepShopping）'塊的末尾添加'keepShopping = true' – 3kings