Question

我一直在使用JCreator上课做作业，JCreator一直给我错误：在AddSubtract类中找不到主要方法，请定义main方法我有两个类AddSubtract和AddSubtractViewer。 AddSubtractViewer有主要方法。当AddSubtractViewer具有main方法时，JCreator会给我上面的错误，但是当我将确切的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();
}*/
}

和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？

Answer 1

问题出现是因为AddSubtract被配置为JCreator中的启动文件。您需要更改启动文件，告诉JCreator您的main()位于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。

当main方法包含在一个类中时，我的程序会编译，但不会在main方法分开时编译

1 个答案: