package com.sina.www.lx;

import java.
import java.awt.Container;
import java.awt.Graphics;
import java.awt.Panel;

import javax.swing.DebugGraphics;
import javax.swing.JFrame;

public class TestC {
    TestC()
    {
        JFrame jf = new JFrame("我的窗口");
        jf.setBounds(200, 200,300,300);
        jf.setResizable(false);
        jf.setVisible(true);
        Graphics g = new DebugGraphics();
        g.drawLine(200, 200,255,255);
        Panel p = new Panel();
        p.add(g);
                  jf.add(p);
        
    }
    public static void main(String[] args)
    {
        new TestC();
    }

}

麻烦大家,我想在窗体中画一条线.但是好象p.add(g)出现错误了..
Exception in thread "main" java.lang.Error: Unresolved compilation problem:
    The method add(Component) in the type Container is not applicable for the arguments (Graphics)

    at com.sina.www.lx.TestC.<init>(TestC.java:22)
    at com.sina.www.lx.TestC.main(TestC.java:28)
请问一下大家,如何把Graphics添加到窗体中显示出来??谢谢了!!~

你的add（）方法用错了add(components),而graphics 需要paint到component上
你的程序可以改为：
import java.awt.Graphics;
import javax.swing.JFrame;
public class test extends JFrame{
    public test(){
        this.setTitle("我的窗口");
        this.setBounds(200, 200,300,300);
        this.setResizable(false);
        this.setVisible(true);
        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }
    public void paint(Graphics g){
            g.drawLine(200, 200,255,255);
    }
    public static void main(String args[]){
        new test();
    }
}

谢谢ls了,我想问一下,如果要用graphics这个类得需要paint到component上.
麻烦问一下,paint和components都是什么??谢谢了

其实没什么，我就是省略了。这句意思,如果要用graphics这个类得需要绘制到组件上.