android - 为什么 ListView.getCount() 比 Cursor.getCount() 大 1

Question

我有这个代码:

cursor = tbDispositivos.fetchAll();
if(cursor.getCount() > 0){
    TextView emptyText = (TextView) findViewById(android.R.id.empty);
    emptyText.setVisibility(View.GONE);
}
adapter = new DispositivosCursorAdapter(this, cursor);  

dispositivosList = (ListView) findViewById(android.R.id.list);  
dispositivosList.setAdapter(adapter);  

cursorCount = cursor.getCount();
listViewCount = dispositivosList.getCount();  

listViewCount 比 cursorCount 大 1。为什么？

Answer 1

cursor.getCount() // number of data items in the cursor
adapter.getCount() // number of data items passed in by the cursor (or at least that is what a custom adapter should report)
listview.getCount() // number of data items from the adapter + a header and/or footer view

因此使用页眉或页脚将使 listview.getCount() 比 cursor.getCount() 大 1。如果您同时使用页眉和页脚，那么它将增加 2。