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我一直在为使用 JCreator 的课程做作业，而 JCreator 一直给我错误：在 AddSubtract 类中找不到主要方法，请定义主要方法我有两个类 AddSubtract 和 AddSubtractViewer。AddSubtractViewer 有 main 方法。当 AddSubtractViewer 有 main 方法时，JCreator 给了我上述错误，但当我将确切的 main 方法复制并粘贴到 AddSubtract 类中时却没有。以下是代码：

import java.awt.*;
import java.awt.event.*;
import javax.swing.JFrame;
import javax.swing.JButton;
import javax.swing.JLabel;
import javax.swing.JPanel;

public class AddSubtract
{
private static final int FRAME_WIDTH = 300;
private static final int FRAME_HEIGHT = 100;
private static final int INCREMENT = 5;
private int value;
private JButton buttonAdd, buttonSubtract;
private JLabel label;
private JFrame frame;
private JPanel panel;

//Sets up the GUI
public AddSubtract()
{
    frame = new JFrame ("Add and Subtract");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    value = 50;
    label = new JLabel("Value: " + Integer.toString(value));

    buttonAdd = new JButton("Add");
    buttonSubtract = new JButton("Subtract");

    buttonAdd.addActionListener(new AddButtonListener());
    buttonSubtract.addActionListener(new SubtractButtonListener());     

    panel = new JPanel();
    panel.setPreferredSize(new Dimension(FRAME_WIDTH, FRAME_HEIGHT));
    panel.setBackground(Color.lightGray);
    panel.add(label);
    panel.add(buttonAdd);
    panel.add(buttonSubtract);

    frame.add(panel);

}

//displays the primary application frame
public void display()
{
    frame.pack();
    frame.setVisible(true);
}

private class AddButtonListener implements ActionListener
{
    public void actionPerformed(ActionEvent event)
    {
        value = value + INCREMENT;
        label.setText("Vaue: " + Integer.toString(value));
    }
}

private class SubtractButtonListener implements ActionListener
{
    public void actionPerformed(ActionEvent event)
    {
        value = value - INCREMENT;
        label.setText("Value : " + Integer.toString(value));
    }
}   

/*public static void main(String[] args) 
{
    AddSubtract application = new AddSubtract();
    application.display();
}*/
}

AddSubtractViewer 是

import javax.swing.JFrame;
import javax.swing.JButton;
import java.awt.event.ActionListener;

public class AddSubtractViewer
{

//execute application
public static void main(String[] args) 
{
    AddSubtract application = new AddSubtract();
    application.display();      
}

}

为什么会这样？

4

1 回答 1

2

出现问题是因为AddSubtract在 JCreator 中配置为您的启动文件。您需要更改启动文件以告诉 JCreator 您main()位于 中AddSubtractViewer，如下所示：

  • 从项目菜单中选择项目设置...
  • 从运行：窗口中选择AddSubtractViewer作为主文件。
于 2014-05-19T02:56:32.497 回答