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Posted 9 Sep 2011

# ASP.NET TreeView Sort

, 11 Sep 2011
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Easy way to sort nodes in a TreeView using a recursive function.
A few days ago, I needed to sort the nodes of a tree view. The solutions that I found over the Internet did not please me, so I decided to write my own. This solution is a simple recursive function that sorts tree nodes in an alphabetic order.

```TreeView mytree = new TreeView();

Then simply call the sort function with the main node as the argument:

`sort(node);`

Here is the recursive function:

```private void sort(TreeNode node)
{
foreach (TreeNode n in node.ChildNodes)
sort(n);
try
{
TreeNode temp = null;
List<TreeNode> childs = new List<TreeNode>();
while(node.ChildNodes.Count>0)
{
foreach (TreeNode n in node.ChildNodes)
if (temp == null || n.Text[0] < temp.Text[0])
temp = n;
node.ChildNodes.Remove(temp);
temp = null;
}
node.ChildNodes.Clear();
foreach (TreeNode a in childs)
}
catch { }
}```

## About the Author

 Software Developer (Senior) Martifer Inovação e Gestão Portugal
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## Comments and Discussions

 First Prev Next
 incorrect comparison Member 1024692319-Nov-14 3:04 Member 10246923 19-Nov-14 3:04
 compare full words Klimovec12-Apr-12 2:49 Klimovec 12-Apr-12 2:49
 Heyy it worked for me. Currently i have a treeview which pop... rjkumar19879-Jan-12 2:27 rjkumar1987 9-Jan-12 2:27
 Re: just replace the logical comparison "n.Text[0] < temp.Text[0... brunofer200714-Jan-12 23:59 brunofer2007 14-Jan-12 23:59
 1-The datasource should be sort not the tree in asp.net. An... JoePatent13-Sep-11 8:03 JoePatent 13-Sep-11 8:03
 Re: 1 - Sometimes a TreeView doesn't have necessarily a datasour... brunofer200714-Sep-11 0:36 brunofer2007 14-Sep-11 0:36
 1 - Sometimes a TreeView doesn't have necessarily a datasource. The nodes could be added manually (that was my case). 2 - If you watch carefully the code, you see that recursive function it's only called when a node has childnodes: foreach (TreeNode n in node.ChildNodes) sort(n); the recursive function is called as many child nodes you have, so you can predict the number of iterations 3 - I'll explain this step to you: - temp variable is initialized to null. - for each child node: if the temp is null, temp = childnode. if temp != null, if the first character of childNode < fisrt character of Temp, temp = childNode - when you reach the end of for each statment, the Temp variable has the lowest start character node. - add that node to List "childs", this way the list will be filled alphabetically. - delete temp node from child node. - start all over again (the temp variable is set to null to store again the lowest start letter node). - this cycle stops when there are no more childnodes: while(node.ChildNodes.Count>0) - then, you simply add again the childnode in the node (alphabetically sorted): foreach (TreeNode a in childs) node.ChildNodes.Add(a); 4 - and finally, as I mention before, the sort() method for TreeView is not present on WebForms (ASP.NET).
 Could I ask, why can't you use the default TreeView Sort met... George Swan11-Sep-11 20:11 George Swan 11-Sep-11 20:11
 Re: Hello George, as you can see in the title, this solution is ... brunofer200711-Sep-11 22:21 brunofer2007 11-Sep-11 22:21
 Last Visit: 31-Dec-99 18:00     Last Update: 22-Jul-17 17:29 Refresh 1

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