how to show table data in tree structure view in asp.net c#

Question

I have the following DataTable:

A	B	C
A1	B1	C1
A1	B2	C2
A2	B2	C2
A3	B3	C3

I Want to show it in hierarchy structure like below.

 A1
   |_B1
      |_C1
   |_B2
      |_C2
 A2
   |_B2
      |_C2
 A3
   |_B3
      |_C3

I did a deep search and I could not found something helpful.I am using asp.net c#.

Want to show it in hierarchy tree structure like.

I am using asp.net c#.