TreeView Control Performance REALLY LOW on searching a Node

nitin 0

I have more than 20, 000 nodes , parent node having sub nodes and again subnodes exactly like windows explorer structure with files and folders. I populate the tree on "afterexpand" event by passing the parentnodeid and getting child nodes. The problem is with the search, suppose I want to search a particular node I check the Tag property of currentnode to my searchnode and search recursively but the problem is since I donot have treeview loaded I have to call tnode.expand() to populate the parentnode with chlid nodes and then I see if Tag property of my search node matches one by one with child nodes, if not drill to sub levels further and do the same. To expand each node one by one and check for search node takes hell lot of time. Can anyone suggest better way .Here is the code below public void SearchRecursive(TreeNode ParentNode, TreeNode MyTreeNode) { foreach (TreeNode tNode in ParentNode.Nodes) { if (tNode.Tag.ToString() == MyTreeNode.Tag.ToString()) { this.treeView1.SelectedNode = tNode; this.treeView1.SelectedNode.EnsureVisible(); break; } else { tNode.Expand(); if (tNode.GetNodeCount(true) > 0) SearchRecursive(tNode,MyTreeNode); } } }

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Mahesh Chand22y ago
Your TreeView actually be representing an XML document. Each XML node will have parent , node ID, and level attributes so you can navigate through nodes similar to a tree. So basically you load XMLDocument and start loading TreeView using the second thread. When a user searches, you actually be searching an XML document. Once a document is found in the XML document using XPath or other XML search related classes, you need to store the path and start expanding the tree nodes for that path. You will have to play around with this logic. I don't know any code samples that does the same. James has an application "XML TreeView" that shows how to build the XML tree. You can expand the same application ;) and add search and other functionalities. http://www.c-sharpcorner.com/Code/2003/Sept/XMLTreeView.asp
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nitin 022y ago
Hi Mahesh, Thanks again for the reply, the main issue is with the search , on the basis of what user is searching i disply search result in a list view and on double clicking a particular node in list view I iterate through the treeview to display the node by comparing their tags which has unique data but for that I have to preload the complete treeview, the suggestion you have given I think will have one issue that if user searches a node which is say at 10th level then he has to wait till second thread loads it. The earlier suggestion by you was reflection, I looked a bit further that if i use dynamic invocation with relection emit, the recursive building of tree will be very quick, but I cannot find any help for this relection emit approach, can you give some ideas or if you can guide to some website or sample code?
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Mahesh Chand22y ago
Since you've a quite large TreeView nodes, I would load first 2 levels of TreeView on intial load and rest I will run in a second thread. When a user expands a Tree node, I would load that node in main thread and rest will be filled by second thread.
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nitin 022y ago
Hi Mahesh, Thanks for your reply, but does that mean that I preload the complete Treeview with al the nodes as an XMLdocument or as XML Reflection treeview rather than loading the childnodes on treeview expand event (when a partcular node is clicked)? Nitin
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Mahesh Chand22y ago
There are two different approaches to achieve this - database and XML storage. If you build an XML reflectin TreeView, you can use XPath and other search options available for XML in the .NET Framework class library. After finding the result, direct move to the node you are looking for. Obviously your XML shall store the node information as well such as depth and parent.
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