Usually TreeView is binded hierarchical data by
sitemap, but Sitemap is predefined navigational map. Our business requires to
populate database data to TreeView. This article presents how to bind treeview
control by datatable dynamically. The example of Populated tree is below.
![p1.jpg]()
private
void PopulateParentTree(object
sender, EventArgs e)
{
DataTable dt = new
DataTable("Treetbl");
DataSet ds = new
DataSet();
dt.Columns.Add("ID",
typeof(int));
dt.Columns.Add("ParentID",
typeof(int));
dt.Columns.Add("Description",
typeof(string));
dt.Rows.Add(0,
null, "Root",
null);
dt.Rows.Add(1,
0, "Node1", null);
dt.Rows.Add(2,
0, "Node2", null);
dt.Rows.Add(3,
1, "a1", "page1");
dt.Rows.Add(4,
1, "a2", "page2");
dt.Rows.Add(5,
2, "b1", "page3");
dt.Rows.Add(6,
2, "b2", "page4");
dt.Rows.Add(7,
0, "Close Page",
"~/Logout.aspx");
ds.Tables.Add(dt);
ds.Relations.Add("rsParentChild", ds.Tables["Treetbl"].Columns["ID"],
ds.Tables["Treetbl"].Columns["ParentID"]);
if (ds.Tables.Count > 0)
{
foreach (DataRow
dr in ds.Tables["Treetbl"].Rows)
{
if (dr["ParentID"]
== DBNull.Value)
{
TreeNode pNode = new
TreeNode(dr["Description"].ToString());
pNode.PopulateOnDemand = false;
pNode.ToggleExpandState();
DocsMenu.Nodes.Add(pNode);
if (dr.GetChildRows("rsParentChild").Count()
> 0)
{
pNode.Expand();
PopulateChildTree(dr, pNode);
}
}
}
}
}
private void
PopulateChildTree(DataRow dr,
TreeNode pNode)
{
foreach (DataRow
cRow in dr.GetChildRows("rsParentChild"))
{
TreeNode cNode = new
TreeNode(cRow["Description"].ToString());
pNode.ChildNodes.Add(cNode);
if (cRow["ParentID"].ToString()
== "0")
{
cNode.ImageUrl = "";
PopulateChildTree(cRow, cNode);
}
}
}