Question

java 定义一个applet，其中有标明红色和黄色两个按钮，按红色背景变红色，按黄色

Answer 1

public class AppletMainFunction extends Applet{

public int satae = 0;

@Override
public void init() {
MyThreadFunction mt = new MyThreadFunction(this);
mt.start();
}

public void paint(Graphics g) {
if(satae == 0){
g.setColor(Color.BLACK);
}else{
g.setColor(Color.red);
}
g.fillRect(0, 0, 200, 200);

}

}

public class MyThreadFunction extends Thread{

public AppletMainFunction app;

public MyThreadFunction(AppletMainFunction app){
this.app = app;
}

@Override
public void run() {
while(true){
try {
this.sleep(500);
if(app.satae == 0){
app.satae = 1;
}else{
app.satae = 0;
}
app.repaint();

} catch (InterruptedException e) {

e.printStackTrace();
}
}

}

}

每半秒变背景的，你自己改改吧