当使用AsyncTask填充并从ExpandableListView ImageView单击启动时，ListView消失

Question

我正在从可扩展列表的getChildView方法启动ListActivity。

public void onClick(View v) {
    AlertDialog.Builder builder = new AlertDialog.Builder(context);
    builder.setMessage("Do you want see all vendors selling this item?");
    builder.setCancelable(false);
    builder.setPositiveButton("Yes",
        new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int id) {
                Intent intent = new Intent(context, SellerListActivity.class);
                intent.putExtra("category", laptop);
                context.startActivity(intent); 

            }
    });
}

ListAcitivity类onCreate看起来像这样：

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

    String[] from = { "name", "phone" };
    int[] to = {android.R.id.text1, android.R.id.text2 };

    adapter = new SimpleAdapter(SellerListActivity.this, sellerList,
            android.R.layout.simple_list_item_2, from, to);


    SellerListActivity.this.setListAdapter(adapter);

    /*Go and fetch the sellers*/
    new RetrieveContactsAll().execute();
}

RetrieveContactsAll是一个带有以下onPostExecute函数的AsyncTask

protected void onPostExecute(ArrayList<Map<String, String>> sellerList) {
    adapter.notifyDataSetChanged();
    pDialog.dismiss();
} 

问题在于，当我点击可扩展列表子项时，我看到列表视图已填充并在它消失之前暂时显示，并被可扩展列表替换。