IntegralUI TreeListView User Guide - Lidor Systems

if (e.Label != null)
{
if (e.Label.Length > 0)
{
if (e.Label.IndexOfAny(new char[] { '@', '.', ',', '!' }) >= 0)
{
// Cancel the label edit action, inform the user, and
// place the node in edit mode again.
e.Cancel = true;
MessageBox.Show("Invalid node label.\n" + "The invalid
characters are: '@','.', ',', '!'", "Node Label Edit");
node.BeginEdit();
}
}
else
{
// Cancel the label edit action, inform the user, and
// place the node in edit mode again.
e.Cancel = true;
MessageBox.Show("Invalid node label.\nThe label cannot be blank",
"Node Label Edit");
node.BeginEdit();
}
}
}
}
Checked nodes
In order to display checkboxes to the nodes, the CheckBoxes property of the TreeListView
control must be set to True. Every node has a check box shown to the left side of the node space.
Their visibility is controlled by CheckBoxVisible property. In this way, you can decide which nodes
will have checkbox. This is useful for example when you want some node to behave like a header
for other nodes.
The check box can display two or three state values. By default the two-state (checked and
unchecked) behavior is active. If you want to have three-state behavior, at first you need to set
the CheckMode to ThreeState value. Whenever user clicks inside the check box space, it will
cycle the state of the check box through Unchecked, Indeterminate and Checked values.
In some cases you will also want to change the check box state by node selection. In order to do
that, set the AllowSelectionCheck property to True.
The set of checked nodes (only those with CheckState set to Checked) is stored in
CheckedItems collection. This collection is very useful when you want to examine only nodes
that are currently checked.
How to preserve checked nodes
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