Quick slider for the listview list control

How to enable the quick scroll slider of the listview list control
 
Here, the android Development Network tells you that you only need a line of code to help scroll the slider. If you use xml layout, you only need to add android to the listview node: fastscrollenabled = "true". For java code, you can use applistview. setfastscrollenabled (true );
To control enabling. The parameter false is hidden.
 
Another point is that this quick scroll slider does not appear when your scrolling content is small and it is less than the three screen heights of the current listview.
You can use Quick scrolling assistance in listview, gridview, and other subclasses.

Author: "oracle experts, haha"