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It's simple to load treeview nodes from table using a recursive function, but it takes a long time for huge data.
I have a table with these fields: id, title, parentid : that keeps treeview nodes in N level.

This table has more than 70000 rows. When i fill treeview from this table it take a long time (about 9 mins) for completion.

Is there a beter solution to increase loading speed?

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Loading e.g. levels>2 only on expanding the parent ... using Treeview.Items.BeginUpdate/Endupdate ... – bummi Apr 17 at 5:40
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Use a virtual paradigm: load root nodes only and the rest on demand – pf1957 Apr 17 at 5:42
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Yep, virtual control is the solution – David Heffernan Apr 17 at 6:17
@Netlog - Why do you need to load 70000 rows at once? Does not make sense. How many nodes can a user view at one time? 50? 100? Why load them all at once? – Mikey Apr 17 at 7:48
@DavidHeffernan: please back to my question (i did emped my code with TreeView) and let me know how i can do it using VirtualStringTree – Netlog Apr 17 at 7:59
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2 Answers

up vote 4 down vote

You can try TreeView.Items.BeginUpdate/EndUpdate.

But storing 70000 rows in visual control is a questionable idea. Have you considered Virtual TreeView or another way to show only small subset of the data table?

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i'll try beginupdate/end update and let you know result – Netlog Apr 17 at 6:28
i did test VirtualTreeView or TVirtualStringTree , but it's not useful for this purpose , since it can create milions of nodes only for a node and can't create 70000 nodes in N level – Netlog Apr 17 at 6:30
have you idea to fast load nodes in N level? – Netlog Apr 17 at 6:31
@Netlog I'll tell you the result of you Begin/EndUpdate test now. With 70000 nodes, your performance will never be acceptable until you switch to virtual paradigm. – David Heffernan Apr 17 at 6:31
@Netlog You cannot see thousands of nodes simultaneously, and VT maintains only visible nodes - it increases speed drastically – MBo Apr 17 at 10:41
up vote 2 down vote

The standard TTreeView gets slow very quickly as size increases. VirtualTreeview is a perfect solution and can handle millions of nodes without degradation.

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i did test VirtualTreeView or TVirtualStringTree , but it's not useful for this purpose , since it can create milions of nodes only for a node and can't create 70000 nodes in N level – Netlog Apr 17 at 6:26
have you idea to fast load nodes in N level? – Netlog Apr 17 at 6:32
2  
I'm sure that VTT will do you you want if only you learn how to use it. – David Heffernan Apr 17 at 6:34
@Netlog: that is not true. VTV has no limitations as to where the nodes are created. The RootNodeCount determines the number of top-level nodes. Number of child nodes is determined by calling the InitChildren event. – Smasher Apr 17 at 6:37
Dear Experts; i'm newbie in VirtualStringTree. i did edit my post with Treeview filling ,please let me know how i can do it with VST – Netlog Apr 17 at 7:53
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