问题:

I am testing an application where we have a list view with list of images retrieved over network. When i run the application on android device 2.3.3 (WIFI speed 512 KBPS) and check the DDMS (Thread Viewer), the number of threads keeps increasing till 50 from 25. But when i test the same application on device 4.0 (WIFI speed 5 MBPS), number of threads did not increase.

Can anyone help me understand why this is happening ? Is it due to android OS difference or any other reason ?

Thanks in advance.

回答1:

Are you useing AsyncTask. After Android 3.0, the default behavior of AsyncTask is execute in a single thread using SERIAL_EXECUTOR.

If you want AsyncTask run concurrently on any system version, you may use this code.

AsyncTask task = new YourTask(); if (Build.VERSION.SDK_INT

Pre OS 1.6 - Multiple Async Tasks gets executed in sequence. OS 1.6 till OS 2.3 - Async Tasks run in parallel. From 3.0 - Again, Async Tasks gets executed in sequence.

回答2:

Are you using an AsyncTask to execute the background operation? I think there is a difference between the implementation of the AsyncTask between GB and ICS.

Try to add some debug logging when the thread finishes its work and see if there is a difference between the two versions.

回答3:

You can use the AsyncTaskCompat.executeInParallel for API

An exemple of use :

AsyncTaskCompat.executeParallel(new AsyncTask() {         @Override         protected Bitmap doInBackground(Void... params) {             return MediaStore.Images.Thumbnails.getThumbnail(                     imageView.getContext().getContentResolver(),                     id,                     MediaStore.Images.Thumbnails.MINI_KIND,                     null);         }         @Override         protected void onPostExecute(Bitmap bitmap) {             imageView.setImageBitmap(bitmap);             if (bitmap != null) {                 // Add the image to the memory cache first                 CACHE.put(id, bitmap);                 if (listener != null) {                     listener.onImageLoaded(bitmap);                 }             }         }     });

enjoy

转载请标明出处:Android - Async Task behavior in 2.3.3 and 4.0 OS

文章来源: Android - Async Task behavior in 2.3.3 and 4.0 OS

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