这个简单的程序应该能够获得标记百分比和批发成本,并计算出零售价格,我把一个行动监听器放到了CALCULATE按钮上,但是当我按下calculate按钮时出现这个错误:在这个简单的GUI程序中的错误
Exception in thread "AWT-EventQueue-0" java.lang.NumberFormatException:
For input string: "Enter the markup precentage"
at sun.misc.FloatingDecimal.readJavaFormatString(Unknown Source)
at java.lang.Double.parseDouble(Unknown Source)
at mm$CalcListerner.actionPerformed(mm.java:58)
at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
有人可以帮我解决这个问题吗?
有人可以解释这些错误信息,因为我真的没有得到任何的?
我的代码是:
import javax.swing.*;
import java.awt.event.*;
public class mm extends JFrame {
private JTextField WholesaleCost;
private JTextField markupPresentage;
private JLabel WCost;
private JLabel MPrecentage;
private JButton button;
private JPanel pannel;
private final int Width = 250;
private final int height = 320;
public mm() {
setTitle("Retail Price Calculator");
setSize(Width, height);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setVisible(true);
buildPanel();
add(pannel);
}
private void buildPanel() {
WholesaleCost = new JTextField(10);
markupPresentage = new JTextField(10);
WCost = new JLabel("enter the Whole Sale cost");
MPrecentage = new JLabel("Enter the markup precentage");
button = new JButton("Calculate");
button.addActionListener(new CalcListerner());
pannel = new JPanel();
pannel.add(WholesaleCost);
pannel.add(markupPresentage);
pannel.add(WCost);
pannel.add(MPrecentage);
pannel.add(button);
}
private class CalcListerner implements ActionListener {
public void actionPerformed(ActionEvent e) {
String WSaleinput;
String MPres;
WSaleinput = WholesaleCost.getText();
MPres = MPrecentage.getText();
double Value = Double.parseDouble(WSaleinput) * (Double.parseDouble(MPres)/100);
JOptionPane.showMessageDialog(null, "Retail Price is " + Value);
}
}
public static void main(String[] args) {
mm x = new mm();
}
}
是出现什么错误? – Vulcan 2012-08-15 02:48:10
我仍然没有看到它。将它直接添加到您的问题中,因为您可能没有足够的信誉来发布链接。 – Vulcan 2012-08-15 02:48:51
@Vulcan异常在线程 “AWT-EventQueue的-0” java.lang.NumberFormatException:对于输入字符串: “输入标记PRECENTAGE” \t在sun.misc.FloatingDecimal.readJavaFormatString(未知来源) \t在java.lang中。 Double.parseDouble(来源不明) \t在毫米$ CalcListerner.actionPerformed(mm.java:58) \t在javax.swing.AbstractButton.fireActionPerformed(来源不明) \t在javax.swing.AbstractButton中的$ Handler.actionPerformed(未知源) \t at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source) \t at javax.swing.DefaultButtonModel.setPressed(Unknown So urce) \t ...........更多 – ChawBawwa 2012-08-15 02:50:24