Adapter pattern BaseAdapter in Android framework

In the Android framework, Adapter pattern is a pattern used to bind data sources to UI elements. BaseAdapter is a basic adapter class in the Android framework that provides some basic methods and functions for displaying the content of data sources. The BaseAdapter class is located in the android.widget package and is an abstract class that needs to be inherited to create a custom adapter. Here is the complete source code of the BaseAdapter: public abstract class BaseAdapter { //Returns the total number of data items in the data source public abstract int getCount(); //Returns the data item at the specified location public abstract Object getItem(int position); //Returns the unique identifier of a data item at a specified location public abstract long getItemId(int position); //Returns the view used to display the specified location public abstract View getView(int position, View convertView, ViewGroup parent); //Returns the number of types used to display the view at the specified location public int getViewTypeCount() { return 1; } //Returns the view type where the data item at the specified location is located public int getItemViewType(int position) { return 0; } //Returns whether the view at the specified location is available public boolean isEnabled(int position) { return true; } //Returns the ID of the view, if any public long getItemIdAtPosition(int position) { return getItemId(position); } //Remove the specified data item from the adapter public void remove(Object object) { } } Summary: Adapter pattern is a common design mode in Android development, which is mainly used to bind data sources with UI elements to achieve data display and interaction. BaseAdapter is a basic adapter class in the Android framework that provides some basic methods and functions. By inheriting the BaseAdapter class, we can customize the adapter and implement various methods according to actual needs to meet different business needs. By using BaseAdapter, various complex list and grid layouts can be achieved, and data sources and views can be easily managed, achieving dynamic updates of data and reuse of views. At the same time, BaseAdapter also provides some extension methods, such as removing specified data items, to facilitate operations on the data source. It should be noted that although BaseAdapter provides some basic implementation methods, not all methods need to be implemented in custom adapters, and can be selectively implemented according to actual needs.