Here's a sample code of using spinner in android :

```
Spinner spinner = (Spinner) findViewById(R.id.spinner);
ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(this, R.array.gender_array, android.R.layout.simple_spinner_item);
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinner.setAdapter(adapter);

```

I have understood that we need to specify a layout for the datarows in the adapter

But why again using `setDropDownViewResource()` method. I mean what does this function do and also tell me how it is different from the constructor of the `ArrayAdapter`.

I have gone through the documentation, but didn't understand completely.