Question

I have an application that uses images from web a a source. for my application I’m first downloading images in seperate thread and only if image exists on disk I show on the list. Downloader is a seperate thread, but I’m very new using threads and now something else is confusing me. My images are not shown unless I refresh the view, that is my list. Now I needed to show my images so I wrote this in my custom view :

private  Runnable LoaderTask=new Runnable(){
    public void run() {
        if(cellIcon!=null){
            if(iconCache.get(cellIcon)!=null){              
                icon.setImageBitmap(iconCache.get(cellIcon)); 
                mHandler.postDelayed(this, 200);
            }
        }

    }

};
private class ImageThread extends Thread{

    @Override
    public void run() {
        //  mHandler.removeCallbacks(LoaderTask);
          mHandler.postDelayed(LoaderTask, 100);


    }

}

And I trigger my thread like this

  ImageThread thread=new ImageThread();
    thread.start();

the handler is instantiated in the beginning of the class. But when I do this n othing happen until I refresh my views. I tried (Activity).runOnUIThread inside one of my threads I got stackoverflow error. How do I solve that or are there any other advices.you can give me? Thanks

Answer 1

Use AsyncTask. In onPostExecute() method just call a method from the activity and refresh the UI. The onPostExecute() is called when the thread is done.

http://developer.android.com/resources/articles/painless-threading.html

P.S. To call an activity’s method just use Interface.