Question

此代码不会填充矩形。我试图扩展JComponent但我收到了一个错误。我如何扩展JComponent？

 package com.lewis.GooseEgg;
 import java.awt.*;
 import java.awt.image.BufferStrategy;
 import java.awt.image.BufferedImage;
 import java.io.File;
 import java.io.IOException;

 import javax.imageio.ImageIO;
 import javax.swing.JComponent;
 import javax.swing.JFrame;

 public class GooseEgg extends Canvas{ //I couldn't extend JComponent
                                       //How would I also extend JComponent
     protected void paintComponent(Graphics g){
         g.setColor(Color.BLACK);
         g.fillRect(0,0, 100, 100);
     }

public static void main(String[] args) {
    //This is just all the basic stuff I learned                        
    JFrame frame = new JFrame();
    GooseEgg goose = new GooseEgg();
    frame.setResizable(false);
    frame.setTitle("Goose Egg");
    frame.add(goose);
    frame.pack();
    frame.setSize(900, 900);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setLocationRelativeTo(null);
    frame.setVisible(true);
    //The website keeps asking me to add more detail because it says my post is mostly code so I added this. If anyone wants to tutor me at Java
    //I could pay money.
     }

 }

Answer 1

您无需从Canvas和JComponent延伸：您应该只从JComponent延伸。

此外，您不应该pack()和setSize(…)。它们都设置了框架的大小，这没有意义。要么执行pack()（在这种情况下，您还需要指定首选大小，例如通过覆盖getPreferredSize()或将其设置为setPreferredSize(…)）或执行setSize(…) }。

将Canvas更改为JComponent并删除pack()方法调用似乎会产生正确的结果。

我的节目不会画出以下代码：

1 个答案: