Question

出于某种原因，某些Swing组件在我运行程序时不会出现，我无法弄清楚原因。仅显示乘法标签，乘法按钮，总标签和停止按钮。其他人都没有工作。

 import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class BabyCalculatorFinal extends JFrame{

private JLabel AdditionLabel;
private JTextField AdditionField;
private JButton AdditionButton;
private JPanel Multiplication;
private JLabel MultiplicationLabel;
private JTextField MultiplicationField;
private JButton MultiplicationButton;
private JPanel Total;
private JLabel TotalLabel;
private JTextField TotalField;
JButton StopButton;

public BabyCalculatorFinal(){
    setDefaultCloseOperation(EXIT_ON_CLOSE);// 1st thing to do
    setName("Baby Calculator Final"); // 2nd thing to do
    setLayout(new GridLayout(3,0)); //sets grid layout for the entire thing with 3 rows
    // Create Action Event
    BabyCalculatorListener Listener = new BabyCalculatorListener();
    //Addition 
    //Addition Set Layout
    JPanel Addition = new JPanel(new BorderLayout());
    //Addition Features
    AdditionLabel = new JLabel("Amount to add"); //Create label
    AdditionField = new JTextField(10);
    AdditionButton = new JButton("Add");
    //Organize Addition Panel
    Addition.add(AdditionLabel, BorderLayout.WEST);//IMPORTANT FORMAT
    Addition.add(AdditionLabel, BorderLayout.CENTER);
    Addition.add(AdditionButton, BorderLayout.EAST);
    //Add addition Panel to Frame
    add(Addition);
    AdditionButton.addActionListener(Listener);

    //Multiplictation
    //Multiplication Set Layout
    Multiplication = new JPanel();
    Multiplication.setLayout(new BorderLayout());//Trying a different way of setting the layout
    //Multiplication Features
    MultiplicationLabel = new JLabel("Amount to Multiply"); //Create label
    MultiplicationField = new JTextField(10);
    MultiplicationButton = new JButton("Multiply");
    //Organize Multiplication Panel
    Addition.add(MultiplicationLabel, BorderLayout.WEST);
    Addition.add(MultiplicationLabel, BorderLayout.CENTER);
    Addition.add(MultiplicationButton, BorderLayout.EAST);
    //Add Multiplication Panel to Frame
    add(Multiplication);
    MultiplicationButton.addActionListener(Listener);
    //Total
    Total = new JPanel(new FlowLayout(10));
    TotalLabel = new JLabel("Total");
    TotalField = new JTextField();
    TotalField.setText("0.0");
    TotalField.setVisible(false);
    StopButton = new JButton("Stop");
    Total.add(TotalLabel);
    Total.add(TotalField);
    Total.add(StopButton);
    //Add Total Panel to Frame
    add(Total);
    pack();
    setVisible(true);
}

public static void main(String[] args){
    JFrame myFrame = new BabyCalculatorFinal();
}

public class BabyCalculatorListener implements ActionListener{
    public void actionPerformed(ActionEvent e){
        String totalText = TotalField.getText();
        double total = Double.parseDouble(totalText);
        if (e.getSource() == AdditionButton){
        String additionText = AdditionField.getText();
        double addition = Double.parseDouble(additionText);
        total += addition;
       }
       else{
           String multiplicationText = MultiplicationField.getText();
           double multiplication = Double.parseDouble(multiplicationText);
           total += multiplication;
        }
        TotalField.setText(total + "");
    }
}

}

Answer 1

您的代码中充满了拼写错误（？），例如您将AdditionLabel两次添加到JPanel，而不是添加AdditionLabel和AdditionField。并且您在创建Multiplication面板后未使用Addition面板，而是覆盖additionLabel = new JLabel("Amount to add"); // Create label additionField = new JTextField(10); additionButton = new JButton("Add"); // Organize addition Panel addition.add(additionLabel, BorderLayout.WEST);// IMPORTANT FORMAT addition.add(additionField, BorderLayout.CENTER); // instead of additionLabel addition.add(AdditionButton, BorderLayout.EAST); // Add addition Panel to Frame add(addition); AdditionButton.addActionListener(Listener); // Multiplictation // Multiplication Set Layout multiplication = new JPanel(); multiplication.setLayout(new BorderLayout());// Trying a different way // of setting the layout // Multiplication Features multiplicationLabel = new JLabel("Amount to Multiply"); // Create label multiplicationField = new JTextField(10); multiplicationButton = new JButton("Multiply"); // Organize Multiplication Panel multiplication.add(multiplicationLabel, BorderLayout.WEST); // instead of Addition multiplication.add(multiplicationField, BorderLayout.CENTER); multiplication.add(multiplicationButton, BorderLayout.EAST);面板的内容。添加组件的更正片段应该是（我更改了变量名以符合Java约定）：

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JAVA Swing组件不会出现

1 个答案: