ProgressDialog wont show onPreExecute in my asynctask?

Ive looked at some questions and non answer the problem im having..

I have this asyncTask...

  private class LoadData extends AsyncTask<Void, Void, Void>{



    protected Void onPreExecute(Void...arg0){
        super.onPreExecute();

        ProgressDialog dialog = ProgressDialog.show(shoppingClass.this, "", 
                "Loading. Please wait...", true);
        dialog.show();

        return null;

    }
    @Override
    protected Void doInBackground(Void... params) {
        item = we.getText().toString();
        getUserPreference();
       开发者_JAVA技巧 itemLookup.loadUrl(url);
        return null;
    }
    @Override
    protected void onPostExecute(Void notused){
        itemLookup.setVisibility(View.VISIBLE);

    }

}

The problem is the progessDialog is not showing up? I dont know why...Im doing everything write according to the documentation.

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You are not overriding correctly the method. Change onPreExecute to this:

@Override
protected void onPreExecute() {
    super.onPreExecute();

     ProgressDialog dialog = ProgressDialog.show(shoppingClass.this, "", 
            "Loading. Please wait...", true);
     dialog.show();
}

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it could just be that doinbackground is completing too quickly for you to be able to see the dialog.

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Check that shoppingClass.this has the UI context. Also, you shouldn't have to call .show() twice on it and you don't have to return null as its void (lowercase).