Question

package harjutamine;

public class algandmed{

    Button[] whitebutton= new Button[2];
    Button[] blackbutton= new Button[2];

    public algandmed(){

        whitebutton[0] = new Button(5, 1);
        whitebutton[1] = new Button(5, 3);

        blackbutton[0] = new Button(0, 0);
        blackbutton[1] = new Button(0, 2);
    }
}

这是我的主文件的基本信息。我已经尝试algandmed();和algandmed a = new algandmed();来调用我的主文件中的代码，但是我不知道为什么，如果有人解释了原因，我会感激不尽那些不会起作用的东西会起作用。

主要

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

public class Checkerboard extends JPanel implements ActionListener {

    public void drawFrame(Graphics g, int frameNumber, int width, int height) {

        int row;   // Row number, from 0 to 7
        int col;   // Column number, from 0 to 7
        int x, y;   // Top-left corner of square
        for (row = 0; row < 8; row++) {
            //Kabelaud
            for (col = 0; col < 8; col++) {
                x = col * 50;
                y = row * 50;
                if ((row % 2) == (col % 2)) {
                    g.setColor(Color.BLACK);

                } else {
                    g.setColor(Color.WHITE);
                }
                g.fillRect(x, y, 50, 50);
            }
        }
//This is where I try to call the function, but it doesn't work
        algandmed aa = new algandmed();


        for (Button n: (whitebutton)) {
            x = n.col * 50 + 4;
            y = n.row * 50 + 4;
            g.setColor(Color.RED);
            g.drawOval(x, y, 40, 40);
            g.fillOval(x, y, 40, 40);
        }

        for (Button n: (blackbutton)) {
            x = n.col * 50 + 4;
            y = n.row * 50 + 4;
            g.setColor(Color.BLUE);
            g.drawOval(x, y, 40, 40);
            g.fillOval(x, y, 40, 40);
        }




    }

    //------ Implementation details: DO NOT EXPECT TO UNDERSTAND THIS ------
    public static void main(String[] args) {

        JFrame window = new JFrame("Checkerboard");
        Checkerboard drawingArea = new Checkerboard();
        drawingArea.setBackground(Color.WHITE);
        window.setContentPane(drawingArea);
        drawingArea.setPreferredSize(new Dimension(390, 390));
        window.pack();
        window.setLocation(100, 50);
        window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        window.setResizable(false); // The user can't change the size.
        Timer frameTimer = new Timer(20, drawingArea);
        window.setVisible(true);
        //frameTimer.start(); // commented out so we don't get an animation
    } // end main

    private int frameNum;

    public void actionPerformed(ActionEvent evt) {
        frameNum++;
        repaint();
    }

    protected void paintComponent(Graphics g) {
        super.paintComponent(g);
        drawFrame(g, frameNum, getWidth(), getHeight());
    }

}

按钮

package harjutamine;
public class Button{
    int row;
    int col;
    public Button(int r, int c){
        row = r;
        col = c;
    }
}

Answer 1

我想你要说的是你的代码不能编译。 drawFrame方法中没有可变白色按钮的声明。因此，编译器不会编译您的代码。如果你只是粘贴代码algandmed然后你有一个whitebutton声明。然而，这可能不是你想要的。想想哪个类应该拥有/拥有Button Arrays。如果您决定将它们放在alganmed类中，则需要提供正确的变量声明。aa.whitebutton应该有效，因为您创建了一个名为aa的alganmed实例。由于您位于同一个包中，而whitebutton是默认可见性，因此您可以直接从main方法访问它。但请注意，这不是一个好习惯。您不应直接访问其他类内部数据。试着想一下封装alganmed数据的方法。

如何在我的主文件中调用此文件？

1 个答案: