Thread in android not working as expected

Question

I am following a guide that shows how to create a Pong game. There is a part, where I am supposed to create a Thread, and call a function that moves the ball.

This is the code I created:

package com.ozadari.pingpong;

public class PingPongGame extends Thread {
private Ball gameBall;
private PingPongView gameView;

public PingPongGame(Ball theBall,PingPongView mainView)
{
    this.gameBall = theBall;
    this.gameView = mainView;
}

@Override
public void run()
{
    while(true)
    {
        this.gameBall.moveBall();
        this.gameView.postInvalidate();

        try
        {
            PingPongGame.sleep(5);

        }
        catch(InterruptedException e)
        {

            e.printStackTrace();
        }

    }
}}

The thread is called and working, but it doesn't print anything. I tried to cancel the infinte loop and make the loop run 100 times. After I wait a while, it prints to the screen as it should be after 100 runs, but it doesn't print anything in the middle.

What is the problem? How can I fix it?

Answer 1

Unsure from the code you've posted but anyway, you can use a handler and have it run once every second like so (change the time to what you want):

Handler handler = new Handler();
final Runnable r = new Runnable()
{
    public void run() 
        {
             //do your stuff here
              handler.postDelayed(this, 1000);
        }
};

handler.postDelayed(r, 1000);

http://developer.android.com/reference/android/os/Handler.html

You can also use a normal thread, and call start at the end.

Thread thread = new Thread()
{
    @Override
    public void run() {
        try {
            while(true) {
                sleep(1000);
                handler.post(r);
            }
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }
};

thread.start();