TreeListChildrenLoadingEventArgs.Parent Property
Returns the data item that corresponds to the current node.
Namespace: DevExpress.Blazor
Assembly: DevExpress.Blazor.v24.2.dll
NuGet Package: DevExpress.Blazor
#Declaration
public object Parent { get; }
#Property Value
Type | Description |
---|---|
Object | The data item. |
#Remarks
Handle the ChildrenLoading or ChildrenLoadingOnDemand event to populate the TreeList component with hierarchical data in code. Use the Parent
event argument to determine the processed node and assign the node’s children to the Children collection.
The following example switches the TreeList component to on-demand mode:
@inject FileSystemDataProvider FileSystemDataProvider
<DxTreeList Data="TreeListData"
HasChildrenFieldName="HasChildren"
ChildrenLoadingOnDemand="TreeList_ChildrenLoadingOnDemand"
CustomizeCellDisplayText="TreeList_CustomizeCellDisplayText">
<Columns>
<DxTreeListDataColumn FieldName="Name" />
<DxTreeListDataColumn FieldName="Type" Width="100" />
<DxTreeListDataColumn FieldName="DateModified" Width="120" />
<DxTreeListDataColumn FieldName="Size" Width="100" />
</Columns>
</DxTreeList>
@code {
object TreeListData { get; set; }
protected override async Task OnInitializedAsync() {
TreeListData = await FileSystemDataProvider.GetRootItemsAsync();
}
Task TreeList_ChildrenLoadingOnDemand(TreeListChildrenLoadingOnDemandEventArgs e) {
var item = e.Parent as FileSystemDataItem;
e.Children = item.Children;
return Task.CompletedTask;
}
void TreeList_CustomizeCellDisplayText(TreeListCustomizeCellDisplayTextEventArgs e) {
if(e.FieldName == "Size") {
var item = (FileSystemDataItem)e.DataItem;
e.DisplayText = GetSizeColumnDisplayText(item.Type, item.Size);
}
}
string GetSizeColumnDisplayText(FileType fileType, long size) {
if(fileType == FileType.Folder)
return null;
if(size >= 1024)
return string.Format("{0:### ### ###} KB", size / 1024);
return string.Format("{0} Bytes", size);
}
}