可运行不会运行

Question

im trying to check when my user stop scrolling.

To this i use this method:

commentsLayout.setScrollViewListener(new ScrollViewListener() {

            @Override
            public void onScrollChanged(WallScrollView scrollView, int x, int y,
                    int oldx, int oldy) {
                // TODO Auto-generated method stub

                oldCommentsYDiefference = oldy;
                commentsYDiefference = y;

                             //do something
}

I noticed that when the user stop scrolling the difference between oldCommentsYDiefference and commentsYDiefference is always 1.

So in order to check when my user stop scrolling i thought about creating a thread that checks when the difference of this two number is 1 by using this code:

public void checkFromScrolling()
    {
        new Thread(new Runnable() {
            @Override
            public void run() {

                Log.i("commentsYDiefference", commentsYDiefference+"");
                Log.i("oldCommentsYDiefference", oldCommentsYDiefference+"");

                if(commentsYDiefference - oldCommentsYDiefference == 1 || oldCommentsYDiefference - commentsYDiefference == 1)
                {

                    if(checkWallScroll)
                        new Handler().postDelayed(new Runnable() {
                        @Override
                        public void run() {

                                         //do things

                            oldCommentsYDiefference = commentsYDiefference;

                            checkWallScroll = true;

                            }
                    }, 2000);

                    checkWallScroll = false;
                }
            }
        }).start();
    }

I call checkFromScrolling() in my onCreate.

My problem is that the Runnable is running only once and not all the time. I know this because i get only one call in my Log reports for

Log.i("commentsYDiefference", commentsYDiefference+"");
Log.i("oldCommentsYDiefference", oldCommentsYDiefference+"");

How to make Runnable run all the time the activity is open?

Answer 1

You could add a while-loop checking if a boolean variable (keepRunning) is true. And then you have to set it to false before your activity is closed.