ASP. NET recursively add Tree nodes

Table Design:

Id title parentid

1 Asp.net 0
2 C #0
3 C # _ 0 2
4 C # _ 1 3
5 C # _ 2 4

 

Add a Treeview control to the page.

 

Add nodes by writing:

Private void addnode (int id, treenode parentnode)
{
String SQL = "select * From menu"; // SQL statement
Datatable table = dB. getdb (SQL); // get data

Dataview view = new dataview (table); // Add Table data to the custom View

View. rowfilter = "parentid =" + ID; // set View query Conditions

Foreach (datarowview row in view) // traverses the data in the view
{
Treenode node = new treenode ();

Node. Text = row [1]. tostring ();
Int newid = convert. toint32 (row [0]);

If (parentnode! = NULL)
{
Node. Expanded = false;
Parentnode. childnodes. Add (node );
Addnode (newid, node); // recursive node search
}
Else
{
Treeview1.nodes. Add (node );
Addnode (newid, node );
}

}
}

 

Getdb () method in dB class:

Public static sqlconnection sqlconn ()
{
String sqlconnstr = "database = menutree; Data Source =.; uid = sa; Pwd = 123 ";

Sqlconnection conn = new sqlconnection (sqlconnstr );
Return conn;
}

Public static datatable getdb (string SQL)
{
Sqlconnection connection = sqlconn ();
Sqlcommand comm = new sqlcommand (SQL, connection );

Sqldataadapter ad = new sqldataadapter (Comm );
Datatable table = new datatable ();
Ad. Fill (table );
Return table;
}

 

 

CallCode:

 

Protected void page_load (Object sender, eventargs E)
{

If (! Ispostback)
{
Treeview1.nodes. Clear ();
Addnode (0, (treenode) null );
}
}

Done!