云南大学软件学院JAVA实验九.doc

云南大学软件学院 实 验 报 告 班级：实验目的：Program 1 Create an application ChangeBallColor that displays a panel. ?This panel will contain two buttons (one for red and one for blue). ?It will also display a filled in circle. ?When the user clicks on a button, the circle should change to that color. ?So, if a user clicks the blue button, the circle will change to blue. ?Similarly, if a user clicks the red button, the circle will turn to red. Program 2 Create an application AddCircles that displays a panel. ?This panel will contain two buttons (one for red and one for blue). ?When the user clicks on a button, change a variable called currentColor to that particular color.Now when the user clicks on a space in the panel (outside a button), draw a circle with the current color. ?Have your application just add new circles when the user clicks the mouse. ?Do not erase previous circles. 实验内容： Program 1： Balls.java代码部分 package Lab9; class Balls { //定义圆的颜色type，1表示蓝色，2表示红色 int color=0; //定义圆的位置 int locate=50; public int getColor() { return color; } public void setColor(int color) { this.color = color; } public int getLocate() { return locate; } public void setLocate(int locate) { this.locate = locate; } //构造函数 public Balls(int color, int locate) { this.color=color; this.locate=locate; } } ChangeBallColor.java代码部分 package Lab9; import java.awt.*; import java.awt.event.*; import javax.swing.*; public class ChangeBallColor extends JFrame { //定义组件 JPanel jp; JButton jb1,jb2; Panel mp=null; public static void main(String[] args) { // TODO Auto-generated method stub ChangeBallColor main=new ChangeBallColor(); } //构造函数 public ChangeBallColor() { mp=new Panel(); jp=new JPanel(); jb1=new JButton(蓝色); jb2=new JButton(红色); jp.add(jb1); jp.add(jb2); //注册监听 jb1.addActionListener(mp); jb1.setActionCommand(蓝色); jb2.addActionListener(mp); jb2.setActionCommand(红色); this.add(jp,BorderLayout.NORTH); this.add(mp); this.se