How to correctly start activity from PostExecute in Android?

Question

I have an AsyncTask, that fills a custom List with parsed data from Internet. In PostExecute I fill that List and get it ready to transfer it to a new Activity. I do it this way: ``` @Override protected void onPostExecute(List<VideoDataDescription> result) { super.onPostExecute(result); MainActivity.progressDialog.dismiss(); context.startActivity(new Intent(context, ResultsQueryActivity.class)); } ``` where context ``` private Context context; ``` In LogCat after executing this code I get a Java.lang.NullPointerException. Is this possible and correct to start an Activity as I do it? UPD I have added ``` private Context mContext; public YoutubeAndYahooParser(Context context) { super(); this.mContext = context; } ``` to initialize context and call ``` YoutubeAndYahooParser youtubeAndYahooParser = new YoutubeAndYahooParser(ResultsQueryActivity.this); youtubeAndYahooParser.execute("my string to pass in asynctak"); ``` After this in PostExecute ``` Intent intent = new Intent(mContext, Resu…

Accepted Answer

You should pass in the application context rather than a context from the local activity. I.e. use context.getApplicationContext() and save that in a local variable in your AsyncTask subsclass.

The code might looks something like this:

```
public class MyAsyncTask extends AsyncTask {

Context context;
    private MyAsyncTask(Context context) {
        this.context = context.getApplicationContext();
    }

@Override
    protected Object doInBackground(Object... params) {
        ...
    }

@Override
    protected void onPostExecute(List<VideoDataDescription> result) {
        super.onPostExecute(result);
        MainActivity.progressDialog.dismiss();

context.startActivity(new Intent(context, ResultsQueryActivity.class));
    }
}
```

you'd call it like this:

```
   new MyAsyncTask(context).execute();
```

How to correctly start activity from PostExecute in Android?

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