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POWhat happens to an AsyncTask when the launching activity is stopped/destroyed while it is still running?
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  1. POWhat happens to an AsyncTask when the launching activity is stopped/destroyed while it is still running?
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    copied!<p>I've seen few questions nearly identical to mine, but I couldn't find a complete answer that satisfies all my doubts.. so here I am.. Suppose that you have an activity with an inner class that extends the <code>AsyncTask</code> class like this:</p> <pre class="lang-java prettyprint-override"><code>public class MyActivity extends Activity { private class DownloadImageTask extends AsyncTask&lt;String, Void, Bitmap&gt; { protected Bitmap doInBackground(String... urls) { return DownloadImage(urls[0]); } protected void onPostExecute(Bitmap result) { ImageView img = (ImageView) findViewById(R.id.img); img.setImageBitmap(result); } } @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); new DownloadImageTask().execute("http://mysite.com/image.png") } } </code></pre> <p>Suppose that the activity is paused or destroyed (maybe the two cases are different) while the <code>DownloadImageTask</code> is still running in background.. then, the <code>DownloadImageTask</code>'s methods that run on the activity UI thread can be triggered and the <code>DownloadImageTask</code> may try to access Activity's methods (it is an inner class, so it can access the methods and instance variables of the outer class) with a paused or destroyed Activity, like the call to <code>findViewByID</code> in the example below.. what happens then? Does it silently fail? Does it produce any exception? Will the user be notified that something has gone wrong? </p> <p>If we should take care that the launching thread (the Activity in this case) is still alive when running-on-UI methods are invoked, how can we accomplish that from within the <code>AsyncTask</code>?</p> <p>I'm sorry if you find this as a duplicate question, but maybe this question is a bit more articulated and someone can answer with greater detail</p>
 

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