怎样在窗体上画矩形？我写的代码，大家帮我看一下。
/*
* ClassDemol.java
*
* Created on 2007年4月5日, 下午3:33
*
* To change this template, choose Tools | Template Manager
* and open the template in the editor.
*/

package hhh;

import java.awt.Graphics;

/**
*
* @author Administrator
*/
public class ClassDemol {

/** Creates a new instance of ClassDemol */
public ClassDemol() {
}

private int x;

private int y;

private int width;

private int height;

public void init() {
width = 60;
height = 60;
}

public void SetPosition(int xPos, int yPos) {
x=xPos;
y=yPos;
}

public void paint(Graphics g) {
SetPosition(20,20);
g.drawRect(x,y,width,height);
g.drawString( "1的位置 "+x,20,100);
g.drawString( "1的位置 "+y,20,120);

g.drawRect(x,y,width,height);
g.drawString( "2的位置 "+x,170,100);
g.drawString( "2的位置 "+y,170,120);

}


}


/*
* Main.java
*
* Created on 2007年4月2日, 上午8:19
*
* To change this template, choose Tools | Template Manager
* and open the template in the editor.
*/

package hhh;

import java.awt.*;

import java.awt.event.*;

import javax.swing.*;

import java.io.*;




/**
*
* @author Administrator
*/
public class Main extends Frame{

/** Creates a new instance of Main */
public Main() {
super( "drawOval Example ");
setSize(200, 200);
show();
}


/**
* @param args the command line arguments
*/
public static void main(String[] args) {
// TODO code application logic here
Main m = new Main();
ClassDemol c = new ClassDemol();
c.init();
c.paint(m.getGraphics());

}

}


程序可以运行，但是矩形出不来，只出来窗体。
请大家告诉我，谢谢!


[解决办法]
我的感觉：是不是由于调用c.paint()的时候，其实窗体并没有显示完整，那么等到窗体完全显示出来之后又做了自动刷新，导致画上去的内容丢失了？试着override Frame.paint()方法，将你的图形绘画过程加到里面看看。
[解决办法]
CORE JAVA 的图形编程那一章里面有，椭圆。矩形都有。JAVA有直接的函数。不用这么麻烦的。
[解决办法]
override Frame里面的paint()方法是王道啊
[解决办法]
import java.awt.Graphics;

import java.awt.Frame;
import java.awt.Panel;
class ClassDemo extends Panel {


public ClassDemo() {
}

private int x;

private int y;

private int width;

private int height;

public void init() {
width = 60;
height = 60;
}

public void SetPosition(int xPos, int yPos) {
x=xPos;
y=yPos;
}

public void paint(Graphics g) {
SetPosition(20,20);
g.drawRect(x,y,width,height);
g.drawString( "1µÄλÖà "+x,20,100);
g.drawString( "1µÄλÖà "+y,20,120);

g.drawRect(x,y,width,height);
g.drawString( "2µÄλÖà "+x,170,100);
g.drawString( "2µÄλÖà "+y,170,120);

}


}




public class Main extends Frame{

public Main() {
super( "drawOval Example ");
setSize(200, 200);
show();
}


public static void main(String[] args) {
Main m = new Main();

ClassDemo c = new ClassDemo();
c.init();

m.add(c);

}

}

帮你改了下,
[解决办法]
楼上的改的对