Proper usage of AsyncTask? : <p>I'm trying to use AsyncTask in the main class of the app as exercise. I included the basic code that i'm trying to understand.The error is the <code>DownloadFilesTask must be declared abstract or implement abstract method doInBackground</code></p>

<p>Java code;</p>

<pre><code>import android.media.Image;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.os.AsyncTask;
import android.widget.ImageView;

public class MainActivity extends AppCompatActivity {

    ImageView image = (ImageView)findViewById(R.id.BackGroundForAll);

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    private class DownloadFilesTask extends AsyncTask&lt;Void, Void, Void&gt; {
        protected Long doInBackground(Void....Void) {

        }

        protected void onProgressUpdate(Integer... progress) {

        }

        protected void onPostExecute(Long result) {

        }
    }
}
</code></pre>
