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Overview

RadTreeView Tri-State CheckBoxes Overview

The Tri-State CheckBox mode of RadTreeView allows for Nodes' CheckBoxes (when enabled) to have an additional, third state - Indeterminate. A Node's CheckBox is in Indeterminatestate if it has both Checked and Unchecked CheckBoxes of child Nodes.

When RadTreeView is in Tri-State CheckBox mode, a Node's CheckBox can be in either of the following states:

  • Checked - CheckBoxes of all child Nodes are **Checked.

  • Unchecked - CheckBoxes of all child Nodes are Unchecked.

  • Indeterminate - there are Checked and Unchecked child Nodes' CheckBoxes.

A CheckBox in Tri-State-enabled TreeView goes through its states in the following order:

  • Checked -> Unchecked

  • Unchecked -> Checked

  • Indeterminate -> Checked

The Tri-State CheckBox mode of RadTreeView is enabled by setting the TriStateCheckBoxes property of the control to True. A prerequisite for this mode to work is to have enabled also CheckBoxes for Nodes.

An addition to the Tri-State CheckBox mode of RadTreeView is the "Check Child Nodes" functionality. When the CheckChildNodes property of RadTreeView is set to True and if:

  • A parent Node's CheckBox is checked then all child Nodes' CheckBoxes are also checked.

  • A parent Node's CheckBox is unchecked then all child Node's CheckBoxes are also unchecked.

The Indeterminate state of a Node is not persisted. That is if a Node's CheckBox is in Indeterminatestate and is unchecked, it can no longer return in the same Indeterminate state.

caution

Tri-State CheckBoxes are actually rendered as <span> elements with predefined CSS styles. They are not styled by the RadFormDectorator control. For more information, please read the Tri-Sate client-side specifics topic.