CODEWITHSUNDEEP
androidmultithreading
Burak
Burak

Reputation: 5764

Cannot create handler inside thread

I download a JSON string that includes background image URL of a View. Download code is inside doInBackground(Object... params). For loading images, I am using Universal Image Loader.

ImageLoader.getInstance().loadImage(shop.background, new ImageLoadingListener() {

    public void onLoadingStarted(String imageUri, View view) {
        // TODO Auto-generated method stub
    }

    public void onLoadingFailed(String imageUri, View view, 
            FailReason failReason) {
        // TODO Auto-generated method stub
    }

    public void onLoadingComplete(String imageUri, View view, Bitmap loadedImage) {
        // TODO Auto-generated method stub
        Drawable d = new BitmapDrawable(getResources(),loadedImage);
        mainLayout.setBackgroundDrawable(d);
    }

    public void onLoadingCancelled(String imageUri, View view) {
        // TODO Auto-generated method stub
    }
});

I am getting 

java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()

Where am I wrong?

Upvotes: 1

Views: 499

Answers (3)

Nicolás Loaiza
Nicolás Loaiza

Reputation: 1015

Try with this.

            runOnUiThread(new Runnable() {
                @Override
                public void run() {
                    mainLayout.setBackgroundDrawable(d);
                }
            });

Upvotes: 0

Leonidos
Leonidos

Reputation: 10518

Move ImageLoader's code to onPostExecute of your asyncTask. You cant create handler in any thread (ImageLoader needs a handler I suppose). You need a thread with looper and Looper.prepare() being called. AsyncTask's threads dont have looper. So move code to onPostExecute to run it on main thread.

Upvotes: 1

Martin Cazares
Martin Cazares

Reputation: 13705

You are wrong in the point where you are trying to create a handler from a worker thread that has not called Looper.prepare(), maybe you didn't even deliberately do it, however there's plenty of methods that create handlers in order to modify Views, usually this handlers attach to the main UI Thread, however is very likely that you are calling a method trying to create the handler from a Worker Thread, If so, what you have to do is, calling that method from main UI, but make sure it will not froze your UI, if that's the case create your own handler and execute it once you are done, or call the runOnUIThread method if you are in an Activity when needed...

Hope this Helps.

Regards!

Upvotes: 0

Related Questions