How do I set an image for some but not all nodes in a TreeView?

Question

I have a TreeView windows forms control with an ImageList, and I want some of the nodes to display images, but the others to not have images.

I don't want a blank space where the image should be. I don't want an image that looks like the lines that the TreeView would draw if it didn't have an ImageList. How do I get it to draw images for some items and not others, without resorting to clumsy hacks like that?

Answer 1

You need to set ImageIndex and SelectedImageIndex to a number that is higher than the number of values in your ImageList. For example, if you create this node and add it to your TreeView:

TreeNode node1 = new TreeNode(string.Empty, 12, 12); // imageList1.Count = 5 

you will have an invisible TreeNode inserted into your TreeView. I changed the background color of my TreeView and it was still invisible.

(I googled this for some time, and I eventually found the answer here: http://www.tech-archive.net/Archive/DotNet/microsoft.public.dotnet.framework.windowsforms/2006-09/msg00322.html)

Answer 2

What I have chosen to do is to use an image of dots for those TreeView nodes that are not supposed to have an image.

I add this image as the last image in the list, and if the item is not supposed to have an image I set it to ImageList.Images.Count-1