Ich versuche, alle Kontakte in Mobile aufzulisten. Bisher hat alles gut funktioniert, aber als ich daran dachte, meinen Code auszuführenAsyncTask Ich bekomme nichts auf dem Bildschirm.

Hier ist ein Codeausschnitt

protected void onCreate(Bundle savedInstanceState) 
{
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_call_list);

    lvCallList = (ListView) findViewById(R.id.lv_call_list);

    new AsyncTask<Void, Void, Void>() 
    {
        @Override
        protected void onPreExecute() 
        {
            pd = ProgressDialog.show(CallListActivity.this,
                    "Loading..", "Please Wait", true, false);
        }// End of onPreExecute method

        @Override
        protected Void doInBackground(Void... params) 
        {
            getContacts();

            return null;
        }// End of doInBackground method

        @Override
        protected void onPostExecute(Void result)
        {
            pd.dismiss();

            lvCallList.setAdapter(new CustomAdapter(CallListActivity.this));

        }//End of onPostExecute method
    }.execute((Void[]) null);
     count = this.displayContactName.size();
    thumbnailsselection = new boolean[count];
}


private void getContacts()
{
    ContentResolver cr = getContentResolver();
    Cursor cur = cr.query(ContactsContract.Contacts.CONTENT_URI, null,null, null, null);
    if (cur.getCount() > 0)
    {
        while (cur.moveToNext())
        {
            String id = cur.getString(cur.getColumnIndex(ContactsContract.Contacts._ID));
            String name = cur.getString(cur.getColumnIndex(ContactsContract.Contacts.DISPLAY_NAME));

            this.displayContactName.add(name);
            if (Integer.parseInt(cur.getString(cur.getColumnIndex(ContactsContract.Contacts.HAS_PHONE_NUMBER))) > 0)
            {
                Cursor pCur = cr.query( ContactsContract.CommonDataKinds.Phone.CONTENT_URI,
                                        null,
                                        ContactsContract.CommonDataKinds.Phone.CONTACT_ID +" = ?", 
                                        new String[]{id}, 
                                        null);
                while (pCur.moveToNext())
                {
                    String phoneNumber = pCur.getString(pCur.getColumnIndex( ContactsContract.CommonDataKinds.Phone.NUMBER));
                    this.displayContactNumber.add(phoneNumber);
                } 
                pCur.close();
            }
        }
    }
}

 public class CustomAdapter extends BaseAdapter 
{
    /*
     * Variables Declaration section
     */
    private Context mContext;

    public CustomAdapter(Context context) 
    {
        mContext = context;
    }//End of CustomAdapter constructor

    public int getCount() 
    {
        return count;
    }//End of getCount method

    public Object getItem(int position) 
    {
        return position;
    }//End of getItem method

    public long getItemId(int position) 
    {
        return position;
    }//End of getItemId method

    public View getView(int position, View convertView, ViewGroup parent) 
    {

        return convertView;
    }//End of getView method
}//End of CustomAdapter instance inner class

class ViewHolder 
{
    TextView textviewName;
    TextView textviewNumber;
    CheckBox checkbox;
    int id;
}//End of ViewHolder instance inner class

displayContactName Wert unter Verwendung des Haltepunkts beipd.dismiss(); ist

displayContactName  ArrayList  (id=830007844896)    
array   Object[12]  (id=830007907208)   
    [0] "Rrs" (id=830007907144) 
    [1] "Fgsd" (id=830007920424)    
    [2] null    
    [3] null    
    [4] null    
    [5] null    
    [6] null    
    [7] null    
    [8] null    
    [9] null    
    [10]    null    
    [11]    null    
modCount    2   
size    2   

Ich weiß nicht, was an meinem Code falsch ist, wenn ich ihn nicht benutzeAsyncTask dann funktioniert mein code einwandfrei, aber wenn ich benutzeAsyncTask Problem kommt. Bitte helfen Sie mir, dieses Rätsel zu lösen.

Danke im Voraus.