下面这段代码为何界面的颜色无法修改？？？？

宵 2013-07-07 01:26:58

package event;



import java.awt.Color;

import java.awt.Container;

import java.awt.Graphics;

import java.awt.Graphics2D;

import java.awt.Point;

import java.awt.event.MouseEvent;

import java.awt.event.MouseListener;

import javax.swing.JFrame;



/**

 * 棋子类

 * 其中包括棋子的位置Point，以及棋子的颜色控制标记flag

 * @author Administrator

 *

 */



class Chess

{

	Chess()

	{

		flag = 0;

		p = new Point();

	}

	Point p;

	int flag;

	

}

class MouseEventTest extends JFrame



{

	/**

	 * 

	 */

	private static final long serialVersionUID = 1L;

	

	/**

	 * 保存鼠标位置

	 */

	int mouseX = 0;

	int mouseY = 0;

	Color color;

	

	//表示棋子的个数

	int len = 0;

	//保存棋子信息

	Chess[] chessArr;



	MouseEventTest()

	{

		

		Container container = this.getContentPane();

		container.setBackground(Color.YELLOW);

		chessArr = new Chess[200];

		this.setTitle("鼠标移动测试");

		this.setSize(500,400);

		int screenX = this.getToolkit().getScreenSize().width;

		int screenY = this.getToolkit().getScreenSize().height;

		

		this.setLocation(screenX/2 -250, screenY/2 -200);

//		this.setResizable(false);

		this.setVisible(true);

	

		this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

//		this.setBackground(Color.red);

		

		

		container.addMouseListener(new MouseListener(){



			@Override

			public void mouseClicked(MouseEvent e) {

				// TODO Auto-generated method stub

				MouseEventTest.this.mouseX = e.getX();

				MouseEventTest.this.mouseY = e.getY();

				

				

			

		

				//保存棋子信息，同时len +1

				chessArr[len] = new Chess();

				

				chessArr[len].p.x = e.getX();

				chessArr[len].p.y = e.getY();

				

				chessArr[len].flag = e.getButton();

				len ++;

				

		//		chessArr[]

	//			repaint();

				

			}



			@Override

			public void mousePressed(MouseEvent e) {

				// TODO Auto-generated method stub

				

			}



			@Override

			public void mouseReleased(MouseEvent e) {

				// TODO Auto-generated method stub

				

			}



			@Override

			public void mouseEntered(MouseEvent e) {

				// TODO Auto-generated method stub

				

			}



			@Override

			public void mouseExited(MouseEvent e) {

				// TODO Auto-generated method stub

				

			}

			

		});

	}

	

	public void paint(Graphics g)

	{

//		super.paint(g);

//		this.getContentPane().setBackground(Color.yellow);

		Graphics2D g2 = (Graphics2D)g;

		g2.setColor(color);

		

		for(int i=0;i<len;i++)

		{

			if(chessArr[i].flag == 1)

				g2.setColor(Color.BLUE);

			else if(chessArr[i].flag == 2)

				g2.setColor(Color.green);

			else if(chessArr[i].flag == 3)

				g2.setColor(Color.ORANGE);

			if(mouseX >10) //因为程序启动后  会有一个默认的左上角的位置 0,0,我们进行操作的时候

				//会优先在那个位置进行绘图

			g2.drawOval(chessArr[i].p.x, chessArr[i].p.y,

							100, 100);

		}

//			g2.drawOval(mouseX, mouseY, 100, 100);

	}

	

	

	public static void main(String[] args)

	{

		new MouseEventTest();

	}



}

执行之后，界面依然是默认的白色。

而如下代码，则可以顺利的修改成其他的颜色。

package event;



import java.awt.Color;

import java.awt.Container;

import java.awt.Dimension;

import java.awt.event.MouseEvent;

import java.awt.event.MouseListener;



import javax.swing.JFrame;



public class BackGroundTest extends JFrame {



	/**

	 * 

	 */

	private static final long serialVersionUID = 1L;



	BackGroundTest()

	{

		this.setTitle("这是什么，为什么不能修改颜色");

		this.setVisible(true);

		this.setSize(new Dimension(444,666));

		

		Container container2 = this.getContentPane();

		container2.setBackground(Color.red);

		

		container2.addMouseListener(new MouseListener(){



			@Override

			public void mouseClicked(MouseEvent e) {

				// TODO Auto-generated method stub

	//			container.setBackground(Color.red);

				System.out.print(e.getButton());

			}



			@Override

			public void mousePressed(MouseEvent e) {

				// TODO Auto-generated method stub

				

			}



			@Override

			public void mouseReleased(MouseEvent e) {

				// TODO Auto-generated method stub

				

			}



			@Override

			public void mouseEntered(MouseEvent e) {

				// TODO Auto-generated method stub

				

			}



			@Override

			public void mouseExited(MouseEvent e) {

				// TODO Auto-generated method stub

				

			}

			

		});

	}

	

	public static void main(String[] args)

	{

		new BackGroundTest();

	}

}