import java.awt.*;
import java.awt.event.*;
public class Draw1
{
public static void main(String[] args)
{
DrawMachine dm=new DrawMachine();
}
}
class DrawMachine extends Frame implements Runnable,ActionListener
{
Button btn1,btn2;
TextField tf;
Thread trd1;
boolean Flag;
public DrawMachine()
{
super("抽奖机");
setVisible(true);
setSize(300,200);
setBackground(Color.cyan);
setLayout(null);
btn1=new Button("开始");
btn2=new Button("停止");
tf=new TextField(100);
add(btn1);
add(btn2);
add(tf);
btn1.setBounds(90,130,50,30);
btn2.setBounds(150,130,50,30);
tf.setBounds(60,80,170,30);
trd1=new Thread(this);
btn1.addActionListener(this);
btn2.addActionListener(this);
addWindowListener(new WindowAdapter()
{
public void windowClosing(WindowEvent e)
{
System.exit(0);
}
});
}
public void actionPerformed(ActionEvent e)
{
if(e.getSource()==btn1)
{
Flag=true;
trd1.start();
btn1.setEnabled(false);
}
if(e.getSource()==btn2)
{
setFlag();
btn1.setEnabled(true);
}
}
public void run()
{
while(Flag)
{
for(int i=1;i<11;i++)
{
tf.setText(""+i);
if(Flag==false)
{
break;
}
}
}
}
public void setFlag()
{
Flag=false;
}
}
//第一次两个按钮都可以使用，第二次点击开始按钮就出错什么原因？谢谢
------解决方案--------------------
线程停止后自动消亡.这就是为什么要在线程加上一个死循环，否则他一执出去，线程就没了。
所以每次点“开始”按扭时，再建一个新的线程就可以了。
- Java code
import java.awt.*;import java.awt.event.*;public class Draw1 { public static void main(String[] args) { DrawMachine dm = new DrawMachine(); }}class DrawMachine extends Frame implements Runnable, ActionListener { Button btn1, btn2; TextField tf; Thread trd1; boolean Flag; public DrawMachine() { super("抽奖机"); setVisible(true); setSize(300, 200); setBackground(Color.cyan); setLayout(null); btn1 = new Button("开始"); btn2 = new Button("停止"); tf = new TextField(100); add(btn1); add(btn2); add(tf); btn1.setBounds(90, 130, 50, 30); btn2.setBounds(150, 130, 50, 30); tf.setBounds(60, 80, 170, 30); btn1.addActionListener(this); btn2.addActionListener(this); addWindowListener(new WindowAdapter() { public void windowClosing(WindowEvent e) { System.exit(0); } }); } public void actionPerformed(ActionEvent e) { if (e.getSource() == btn1) { trd1 = new Thread(this); Flag = true; trd1.start(); btn1.setEnabled(false); } if (e.getSource() == btn2) { setFlag(); btn1.setEnabled(true); } } public void run() { while (Flag) { for (int i = 1; i < 11; i++) { tf.setText("" + i); if (Flag == false) { break; } } } } public void setFlag() { Flag = false; } }