{"id":1461,"date":"2016-04-08T07:59:41","date_gmt":"2016-04-08T07:59:41","guid":{"rendered":"http:\/\/abhiandroid.com\/ui\/?p=1461"},"modified":"2019-06-12T13:02:28","modified_gmt":"2019-06-12T13:02:28","slug":"expandablelistadapter-example-android","status":"publish","type":"post","link":"https:\/\/abhiandroid.com\/ui\/expandablelistadapter-example-android.html","title":{"rendered":"ExpandableListAdapter Tutorial With Example In Android Studio"},"content":{"rendered":"

ExpandableListAdapter is an Adapter that links the ExpandableListView with the underlying data. The implementation of this interface will provide the data for the children and also initiate the views for the children and groups.\u00a0 For customization of List we need to implement ExpandableListAdapter in our custom Adapter.<\/p>\n

\"ExpandableListAdapter<\/p>\n

It is important to remember that\u00a0Adapter acts a\u00a0bridge between UI component and data source that helps us to fill data in UI component. Here in simple words we\u00a0can say an Adapter is that which links an ExpandableListView with the underlying data. The implementation of this Interface will provide access to the data of the children (categorized by groups), and also instantiate views for the children and groups.<\/p>\n

\"ExpandableListAdapter<\/p>\n

Below is the example code of ExpandableListAdapter in which we create an custom Adapter class named \u201c MyExpandableListAdapter \u201d and then implements expandable list adapter in that class.<\/p>\n

public class MyExpandableListAdapter implements ExpandableListAdapter {\r\n@Override\r\npublic void registerDataSetObserver(DataSetObserver observer) {\r\n\r\n}\r\n\r\n@Override\r\npublic void unregisterDataSetObserver(DataSetObserver observer) {\r\n\r\n}\r\n\r\n@Override\r\npublic int getGroupCount() {\r\nreturn 0;\r\n}\r\n\r\n@Override\r\npublic int getChildrenCount(int groupPosition) {\r\nreturn 0;\r\n}\r\n\r\n@Override\r\npublic Object getGroup(int groupPosition) {\r\nreturn null;\r\n}\r\n\r\n@Override\r\npublic Object getChild(int groupPosition, int childPosition) {\r\nreturn null;\r\n}\r\n\r\n@Override\r\npublic long getGroupId(int groupPosition) {\r\nreturn 0;\r\n}\r\n\r\n@Override\r\npublic long getChildId(int groupPosition, int childPosition) {\r\nreturn 0;\r\n}\r\n\r\n@Override\r\npublic boolean hasStableIds() {\r\nreturn false;\r\n}\r\n\r\n@Override\r\npublic View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) {\r\nreturn null;\r\n}\r\n\r\n@Override\r\npublic View getChildView(int groupPosition, int childPosition, boolean isLastChild, View convertView, ViewGroup parent) {\r\nreturn null;\r\n}\r\n\r\n@Override\r\npublic boolean isChildSelectable(int groupPosition, int childPosition) {\r\nreturn false;\r\n}\r\n\r\n@Override\r\npublic boolean areAllItemsEnabled() {\r\nreturn false;\r\n}\r\n\r\n@Override\r\npublic boolean isEmpty() {\r\nreturn false;\r\n}\r\n\r\n@Override\r\npublic void onGroupExpanded(int groupPosition) {\r\n\r\n}\r\n\r\n@Override\r\npublic void onGroupCollapsed(int groupPosition) {\r\n\r\n}\r\n\r\n@Override\r\npublic long getCombinedChildId(long groupId, long childId) {\r\nreturn 0;\r\n}\r\n\r\n@Override\r\npublic long getCombinedGroupId(long groupId) {\r\nreturn 0;\r\n}\r\n}\r\n<\/pre>\n
In the above code snippet we see the overrided methods of ExpandableListAdapter which are used to set the data in the ExpandableListView. Below is the description of\u00a0 all these methods:<\/p>\n
1. registerDataSetObserver(DataSetObserver observer):<\/strong><\/span> This method is used to register an\u00a0observer\u00a0that is called when changes happen to the data used by this\u00a0adapter.<\/p>\n
Parameters:<\/strong><\/p>\n