How can i change the expand level of nodes in treeView1 according to numericupdown value change ?

Question

I have this method:
void ExpandToLevel(TreeNodeCollection nodes, int level)
if (level > 0)
foreach (TreeNode node in nodes)
node.Expand();
ExpandToLevel(node.Nodes, level - 1);
I added now a new method:
void CollapseToLevel(TreeNodeCollection nodes, int level)
if (level > 0)
foreach (TreeNode node in nodes)
node.Collapse();
CollapseToLevel(node.Nodes, level - 1);
Then in the numericupdown changed value event i did:
decimal oldValue;
private void numericUpDown1_ValueChanged(object sender, EventArgs e)
if (numericUpDown1.Value > oldValue)
ExpandToLevel(treeView1.Nodes, (int)numericUpDown1.Value);
else
CollapseToLevel(treeView1.Nodes, (int)numericUpDown1.Value);
oldValue = numericUpDown1.Value;
When i expand change the numericupdown value up it's expand it fine level by level. But when i collapse it back when changing the numericupdown value back down if i was at value 4 and now changed to value 3 all the nodes collapsed back to root.
I want it to collapse only by one level from 4 to 3 to 2 to 1 when the vlaue is 0 then collapse back to root.
The collapse is not working good.

Answer 1

Hi,
You don't need to loop from the start to collapse it.
Just issue the collapse on the current node; if its not collapsible then nothing will happen.
treeView1.SelectedNode.Collapse();
Happy coding.
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