Minimizing Treenode redrawing?

Tendy 1

I ask this on stackover flow but this might be a more appropite place to post
After working with this treeview below I noticed that when I comment out Application.EnableVisualStyles(); the tree node are drawn significantly less which reduces flickering. I would do this however this changes the whole style of the application which is not something I want. I was wondering if anyone knows how disable that event or if there is a style setting that I could change on the treeview to cause the nodes only to be redrawn on selection and creation. Thanks https://pastebin.com/EKXQW4fw

Daniel Zhang-MSFT 9,626 Reputation points

2020-08-18T06:53:06.957+00:00

Hi Tebdy,
>>when I comment out Application.EnableVisualStyles(); the tree node are drawn significantly less which reduces flickering.
I made a test via your code and I didn’t see the flicker and there was no big change after commenting out Application.EnableVisualStyles().
As shown:( before comment)

After comment:

Could you explain in detail? And Application.EnableVisualStyles() is used to set your controls rendered with current operating system theme settings.
If you comment it, all the controls in your forms are rendered with the classic Windows look.
Best Regards,
Daniel Zhang
Tendy 1 Reputation point

2020-08-19T19:35:38.3+00:00

Hi @Daniel Zhang-MSFT ,
I noticed that when I hover over the glyph +/- it rewrites the node and its last child on enter and exit of hovering. However when I i don't call Application.EnableVisualStyles(), it doesn't rewrite those nodes. Now this was just a test project to determine when the nodes were getting rewritten as the actual application I'm working on is more expansive than this. Theres a lot math happing in the background so the painting of the tree is not always super fast. My thought was that if I could remove as many thing that caused the repaint it would result in less flickering and a smoother experience for the user as the treeview can not be double buffered.
Thanks for the response.
Andrew
Daniel Zhang-MSFT 9,626 Reputation points

2020-08-20T07:58:19.207+00:00

Hi Andrew,
>>as the treeview can not be double buffered.
We all know that the best solution to reduce flicker is to enable double buffering. You can use the setStyle function to set the parameters of the control.
And what I want to add is that when you need to batch update controls such as adding a lot of nodes during initialization, you can use BeginUpdate and EndUpdate to speed it up.
Best Regards,
Daniel Zhang
Tendy 1 Reputation point

2020-08-20T12:58:52.297+00:00

Hi Daniel,
Thank you again for your response, In the treeview documentation for .net, it specifically state that the double buffer property does not affect the treeview system.windows.forms.treeview.doublebuffered. I was taking this as true, but I can see if it affects my form anyway. If you could get someone on your end to see if the doube buffer does affect the treeview and have the documention changed, that would probably help a lot of developers out.
Thanks again
Andrew

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Minimizing Treenode redrawing?

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