guessexample.java

猜数字游戏buttonEnter按钮增加了ActionEvent事件监视器

//GuessExample.java;
import java.awt.*;
import java.awt.event.*;
import java.applet.*;
public class GuessExample extends Applet implements ActionListener
{
    int number;
     TextField inputNumber;
    Label feedBack;
    Button buttonGetNumber,buttonEnter;
    public void init()
    {
        buttonGetNumber=new Button("得到一个随机数");
        feedBack=new Label("无反馈信息",Label.CENTER);
        feedBack.setBackground(Color.green);
        inputNumber=new TextField("0",5);
        buttonEnter=new Button("确定");
        buttonEnter.addActionListener(this);         // buttonEnter按钮增加了ActionEvent事件监视器，监视器为当前Java Applet
        buttonGetNumber.addActionListener(this);     //buttonGetNumber按钮增加了ActionEvent事件监视器，监视器为当前Java Applet
        add(new Label("获取1-100之间的随机数："));
        add(buttonGetNumber);
        add(new Label("请输入您的猜测："));
        add(inputNumber);
        add(new Label("单击确定按钮："));
        add(buttonEnter);
        add(new Label("无反馈信息："));
        add(feedBack);
    }
    public void actionPerformed(ActionEvent e)
    {
        String bt;
        bt=e.getActionCommand();
        if(e.getSource()==buttonGetNumber)   //if(bt==buttonGetNumber.getActionCommand())
        //判断事件源是否是buttonGetNumber//输入数字
        {
            number=(int)(Math.random()*100)+1;
        }
        if(e.getSource()==buttonEnter)   //if(bt==buttonEnter.getActionCommand())
        //【代码4】判断事件源是否是buttonEnter//单击确定按钮
        {
            int guess=0;
            try
            {
                guess=Integer.parseInt(inputNumber.getText());
                //返回inputNumber中的文本
                if(guess==number)
                {
                    feedBack.setText("猜对了");      //feedBack设置文本"猜对了"
                }
                else if(guess>number)
                {
                    feedBack.setText("猜大了");       //feedBack设置文本"猜大了"
                }
                else if(guess<number)
                {
                    feedBack.setText("猜小了");       //feedBack设置文本"猜小了"
                }
            }
            catch(NumberFormatException event)
            {
                feedBack.setText("请输入数字字符");      // feedBack设置文本"请输入数字字符"
            }
        }
    }
}