新人菜鸟求助！

Question

我定义了框架 也定义了面板 为什么只显示框架，没显示Hello,World 呢？import javax.swing.*;
import java.awt.*;public class HelloWorld
{
         public static void main(String[] args)
         {
              TextFrame frame=new TextFrame();              frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);              frame.setVisible(true);         }
}class TextFrame extends JFrame
{
          public TextFrame()
          { 
                setTitle("HelloWorld");
                setSize(WIDTH,HEIGHT);
           
                TextPanel panel=new TextPanel();
                Container contenPane=getContentPane();
                contenPane.add(panel);          }
          public static final int WIDTH=300;
          public static final int HEIGHT=200;
}class TextPanel extends JPanel
{
          public void painComponent(Graphics g)
          {
                    super.paintComponent(g);
                    
                    g.drawString("Hello,World", x, y);
          }
          public int x=100;
          public int y=100;
}

Answer 1

setTitle("HelloWorld"); //设置了窗体的标题栏 HelloWorld 将会显示在 左上角 Java图标旁边

Answer 2

覆盖JPanel 的 painComponent() 方法写错了。   少了个 “t”， 并没覆盖Jpanel的 paintComponent()。 改成 paintComponent() 就好了。

Answer 3

原来有2个HelloWrold啊 晕！！