Android provide variety of widgets on of them is spinner. Spinner is similar to that of the drop-down list in web it allows user to select a single item from list of items.
To add spinner to your layout you need to add <Spinner> element to your layout.
There are two type of spinner and second is the inline list. There is a problem which I faced while using inline list box i.e inline list is not scroll-able. If items count goes beyond the screen size than you can't select the item
To add elements to your spinner you need the list of items for this. If you are not dynamically populating your spinner you can use xml value to fill it. [ strings.xml located inside value folder of android project ]
Now to initialize the spinner the data. Find the view , initialize the items array , add OnItemSelectedListener.
Now to respond to spinner item select OnItemSelectedListener need to be associated with it.