In Android, Adapter is a bridge between UI component and data source that helps us to fill data in UI component. It holds the data and send the data to an Adapter view then view can takes the data from the adapter view and shows the data on different views like as ListView, GridView, Spinner etc. For more customization in Views we uses the base adapter or custom adapters.
There are the some commonly used Adapter in Android used to fill the data in the UI components.
- BaseAdapter – It is parent adapter for all other adapters. BaseAdapter is a common base class of a general implementation of an Adapter that can be used in ListView, GridView, Spinner Whenever we need a customized list in a ListView or customized grids in a GridView we create our own adapter and extend base adapter in that. Base Adapter can be extended to create a custom Adapter for displaying a custom list item. ArrayAdapter is also an implementation of BaseAdapter.
- ArrayAdapter – It is used whenever we have a list of single items which is backed by an array. Whenever we have a list of single items which is backed by an Array, we can use ArrayAdapter. For instance, list of phone contacts, countries or names.
- Custom ArrayAdapter – It is used whenever we need to display a custom list. ArrayAdapter is also an implementation of BaseAdapter, so if we want more customization then we can create a custom adapter and extend ArrayAdapter in that. Since array adapter is an implementation of BaseAdapter, so we can override all the function’s of BaseAdapter in our custom adapter.
- SimpleAdapter – In Android SimpleAdapter is an easy Adapter to map static data to views defined in an XML file(layout). In Android we can specify the data backing to a list as an ArrayList of Maps(i.e. hashmap or other). Each entry in a ArrayList is corresponding to one row of a list.
The Map contains the data for each row. Here we also specify an XML file(custom list items file) that defines the views which is used to display the row, and a mapping from keys in the Map to specific views.
Whenever we have to create a custom list we need to implement custom adapter. As we discuss earlier ArrayAdapter is used when we have a list of single item’s backed by an Array. So if we need more customization in a ListView or a GridView we need to implement simple adapter.
- Custom SimpleAdapter – Whenever we have to create a custom list we need to implement custom adapter. As we discuss earlier ArrayAdapter is used when we have a list of single item’s backed by an Array. So if we need customization in a ListView or a GridView we need to implement simple Adapter but when we need more customization in list or grid items where we have many view’s in a list item and then we have to perform any event like click or any other event to a particular view then we need to implement a custom adapter who fulfills our requirement’s and quite easy to be implemented.
BaseAdapter is the parent adapter for all other adapters so if we extends a SimpleAdapter then we can also override the base adapter’s function in that class.