在panel上画图形 为什么不显示？

[dxy860812]

import javax.swing.JFrame;
import javax.swing.JPanel;
import java.awt.Color;
import java.awt.Graphics;


public class TankWar extends JPanel{
private int x=50,y=50;
public TankWar(){
//this.setBackground(Color.GRAY);

}
protected void painComponent (Graphics g){
super.paintComponent(g);
Color c=g.getColor();
g.setColor(Color.red);
g.drawString("hello", 20, 40);
g.fillOval(x, y, 30, 30);
g.setColor(c);
//x+=5;
}
public static void main(String[] args){
JFrame jf=new JFrame("坦克游戏");
TankWar t=new TankWar();

jf.getContentPane().add(t);
jf.setResizable(false);
jf.setSize(800, 600);
jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
jf.setVisible(true);
jf.validate();
}
}
为什么画出的图形都不显示呢？？

[gloomyfish]

下次重写一个方法的时候一定记得名字要正确，你没有重载paintComponent()

package com.gloomyfish.swing.rounedpanel;

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Graphics;

import javax.swing.JFrame;
import javax.swing.JPanel;

public class TankWar extends JPanel {
	/**
	 * 
	 */
	private static final long serialVersionUID = -368574037499289446L;
	private int x = 50, y = 50;

	public TankWar() {
		// this.setBackground(Color.GRAY);

	}

	protected void paintComponent(Graphics g) {
		// super.paintComponent(g);
		Color c = g.getColor();
		g.setColor(Color.red);
		g.fillOval(x, y, 30, 30);
		g.setColor(c);
		g.drawString("hello", 20, 40);
		// x+=5;
	}

	public static void main(String[] args) {
		JFrame jf = new JFrame("坦克游戏");
		TankWar t = new TankWar();
		jf.setResizable(false);
		jf.setSize(800, 600);
		jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		jf.getContentPane().setLayout(new BorderLayout());
		jf.getContentPane().add(t, BorderLayout.CENTER);
		jf.setVisible(true);
		// jf.validate();
	}
}

[shenhua]

楼上正解，painComponent书写错误，肯定是手写的。可以直接点击重载方法即可。paintComponent

[huntor]

手写的话，加上@Override有拼写错误的话也编译不了