Android Async Image Download from server and storing them in an array

Here is my issue: I am downloading Images from a server async and organize them in an array such as Image[1] would b the equivalent of Image1 the reason why I need the array to be organized is that I am trying to have an image rotating in 360 angle. So when I download the images into the array it seems that it's not doing the job correctly. Any advice is super greatly appreciated.

public class tst extends Activity implements OnClickListener {
TextView t;
Button b1;
ImageView iV;
Bitmap bitmap = null;
Bitmap [] angles;
String stringAngle;

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.test);
    angles = new Bitmap[13];
    b1 = (Button) findViewById(R.id.button1);
    b1.setOnClickListener(this);
    iV = (ImageView) findViewById(R.id.imageView1);

}

@Override
public void onClick(View v) {
    if(v.getId() == R.id.button1){
        //Toast.makeText(getApplicationContext(), "ghjh", Toast.LENGTH_SHORT).show();
        for(int i = 1 ; i<13 ; i++)
        {
            stringAngle = Integer.toString(i);
        new DownloadImageTask()
            .execute("http://www.sampleurl"
                    +stringAngle+".png");
        }
        iV.setImageBitmap(angles[7]);
    }
}

private class DownloadImageTask extends AsyncTask<String, Void, Bitmap> {
    protected Bitmap doInBackground(String... urls) {
        return loadImageFromNetwork(urls[0]);
    }

    protected void onPostExecute(Bitmap result) {
        // Do something with bitmap eg:
        for(int m = 1 ; m<13;m++)
        {
        angles[m] =(Bit开发者_高级运维map) result;
        }

    }
}

private Bitmap loadImageFromNetwork(String url) {

    try {
        bitmap = BitmapFactory.decodeStream((InputStream) new URL(url)
                .getContent());

    } catch (Exception e) {
        e.printStackTrace();
    }
    return bitmap;
}

}

in this case iV.setImageBitmap(angles[7]) always comes back with different results.