DxTreeView.HasChildrenExpression Property
A lambda expression that specifies whether the data item has child items.
Namespace: DevExpress.Blazor
Assembly: DevExpress.Blazor.v20.2.dll
NuGet Package: DevExpress.Blazor
Declaration
[Parameter]
public Expression<Func<object, bool>> HasChildrenExpression { get; set; }
Property Value
Type | Description |
---|---|
Expression<Func<Object, Boolean>> | A lambda expression that returns a Boolean value: true if the data item has child items; otherwise, false. |
Remarks
Use the HasChildrenExpression property in the Load Child Nodes on Demand mode to specify a lambda expression that indicates whether the data item has child items. The TreeView uses this property to render nodes before they are expanded for the first time.
<DxTreeView Data="@DataSource"
LoadChildNodesOnDemand="true"
HasChildrenExpression="@(dataItem => ((DateTimeGroup)dataItem).HasSubGroups)"
ChildrenExpression="@(dataItem => ((DateTimeGroup)dataItem).GetSubGroups())"
TextExpression="@(dataItem => ((DateTimeGroup)dataItem).Title)">
</DxTreeView>
@code {
IEnumerable<DateTimeGroup> DataSource = new List<DateTimeGroup>() {
new DateTimeGroup(new DateTime(DateTime.Now.Year, 1, 1), DateTimeGroupType.Year)
};
}
See Also