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   [Expand]BeforeCollapseEventArgs Class
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    [Expand]TreeList Methods
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 End-User Documentation

TreeList.BeforeCheckNode Event

Occurs before a node's check state is changed.

Namespace:DevExpress.XtraTreeList
Assembly:DevExpress.XtraTreeList.v17.1.dll

Expanded Syntax

Expanded Event Data

The event handler receives an argument of type DevExpress.XtraTreeList.CheckNodeEventArgs containing data related to this event.

Expanded Remarks

The BeforeCheckNode event is raised when an end-user changes a node's check state, and allows you to cancel the operation or specify the required check state.

To cancel the operation, set the event parameter's CanCheck property to false. The previous and current node states are returned by the PrevState and State properties, respectively. You can change the State property's value to specify the required node state.

The following code prevents an end-user from setting nodes to an indeterminate state.

After a node's state has been changed, the AfterCheckNode event is raised.

Expanded See Also

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