asp.net - Generate list of parents-childs (recursive relationship) from Dataset -

i'm trying build list (html) recursive relationship. data in dataset converted data table if it's easier.

i don't know what's best option achieve this. thinking using nested repeaters.

here's data:

__id__ | __name__  | __parent__     | __level__  1      | patrick   |                | 1            2      | mark      |                | 1 3      | scott     | 2              | 2 4      | jason     |                | 1 5      | julian    |                | 1 6      | john      | 6              | 2 7      | steve     |                | 1 8      | george    | 1              | 2 9      | robert    | 1              | 2  10     | rodney    | 8              | 3 

here output want produce

- patrick [1]   - george [8]     - rodney [10]   - robert [9]  - mark [2]   - scott [3]  - julian [5]   - john [6]  - jason [4]  - steve [7] 

the easiest way write recursive method. way operates depend on whether want have method return entire tree-structured list, or output data reads it. if want output data read it, code might this:

private sub outputtree(data datatable, parentid string, indentationlevel integer)     each row datarow in getchildrows(parentid)         outputrow(row, indentationlevel)         outputtree(data, row("id").tostring(), indentationlevel + 1)     next end sub 

the above code assumes implement method called getchildrows returns list of rows contain given parent id. assumes have method called outputrow outputs given row @ given indentation level.

then, call method this:

outputtree(mydatatable, nothing, 0) 

if want build , return tree structure, arguably better approach, code might this:

private function buildtreenodes(data datatable, parentid string) list(of mytreenode)     dim nodes list(ofnew mytreenode)()     each row datarow in getchildrows(parentid)         dim node new treenode()         node.row = row         node.children = buildtreenodes(data, row("id").tostring())         nodes.add(node)     next     return node end sub 

the above code assumes have defined mytreenode class this:

public class mytreenode     public property row datarow     public property children list(of mytreenode) end class 

then call method this:

dim rootlevelnodes list(of mytreenode) = buildtreenodes(mydatatable, nothing)