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V24.2

DxTreeListSummaryItem.SummaryType Property

Specifies the summary function type.

Namespace: DevExpress.Blazor

Assembly: DevExpress.Blazor.v24.2.dll

NuGet Package: DevExpress.Blazor

Declaration

[DefaultValue(TreeListSummaryItemType.None)]
[Parameter]
public TreeListSummaryItemType SummaryType { get; set; }

Property Value

Type Default Description
TreeListSummaryItemType None

An enumeration value.

Available values:

Name Description
Sum

Calculates the sum of all values in a column.

Min

Calculates the minimum value of all values in a column.

Max

Calculates the maximum value of all values in a column.

Count

Calculates the number of values in a column.

Avg

Calculates the average of all values in a column.

Custom

Uses a custom algorithm to calculate a summary value.

None

Does not calculate a summary value.

Remarks

The Blazor TreeList component can calculate predefined and custom total summaries. For more information about summaries in the TreeList component, refer to the following topic: Summary in Blazor TreeList.

Predefined Summary Functions

The TreeList supports the following predefined functions: Sum, Min, Max, Avg, and Count.

Set the FieldName property to the name of a data field whose values are used to calculate the summary.

  • The Count function supports data fields of all types.
  • Min and Max functions support data fields whose values can be compared.
  • Avg and Sum functions require a numeric field.

The following example displays predefined summaries for TreeList columns:

@inject EmployeeTaskService EmployeeTaskService

<DxTreeList Data="TreeListData" KeyFieldName="Id" ParentKeyFieldName="ParentId">
    <Columns>
        <DxTreeListDataColumn FieldName="Name" Caption="Task" />
        <DxTreeListDataColumn FieldName="EmployeeName" />
        <DxTreeListDataColumn FieldName="StartDate" />
        <DxTreeListDataColumn FieldName="DueDate" />
        <DxTreeListDataColumn FieldName="Status" Caption="Progress" DisplayFormat="p0" />
    </Columns>
    <TotalSummary>
        <DxTreeListSummaryItem SummaryType="TreeListSummaryItemType.Count" FieldName="Name" />
        <DxTreeListSummaryItem SummaryType="TreeListSummaryItemType.Min" FieldName="DueDate" ValueDisplayFormat="y" />
        <DxTreeListSummaryItem SummaryType="TreeListSummaryItemType.Max" FieldName="DueDate" ValueDisplayFormat="y" />
        <DxTreeListSummaryItem SummaryType="TreeListSummaryItemType.Avg" FieldName="Status" />
    </TotalSummary>
</DxTreeList>

@code {
    List<EmployeeTask> TreeListData { get; set; }

    protected override void OnInitialized() {
        TreeListData = EmployeeTaskService.GenerateData();
    }
}

TreeList - Summary

Run Demo: Total Summary

Custom Summary Functions

Set the SummaryType property to Custom to create custom summary items. The following code sample calculates the sum for March Sales values against selected TreeList rows:

Run Demo: Custom Summary

@inject ISalesByRegionDataProvider SalesByRegionDataProvider
<DxTreeList @ref="TreeList"
            Data="Data"
            KeyFieldName="ID"
            ParentKeyFieldName="RegionID"
            ShowAllRows="true"
            CustomSummary="TreeList_CustomSummary"
            CustomizeSummaryDisplayText="TreeList_CustomizeSummaryDisplayText"
            SelectedDataItemsChanged="TreeList_SelectedDataItemsChanged">
    <Columns>
        <DxTreeListSelectionColumn Width="50px" />
        <DxTreeListDataColumn FieldName="Region" Width="15%" />
        <DxTreeListDataColumn FieldName="MarchSales" DisplayFormat="c0" Width="25%" />
        <DxTreeListDataColumn FieldName="SeptemberSales" DisplayFormat="c0" Width="15%" />
        <DxTreeListDataColumn FieldName="MarchChange" DisplayFormat="p2" Width="15%" />
        <DxTreeListDataColumn FieldName="SeptemberChange" DisplayFormat="p2" Width="15%" />
        <DxTreeListDataColumn FieldName="MarketShare" DisplayFormat="p0" Width="15%" />
    </Columns>
    <TotalSummary>
        <DxTreeListSummaryItem SummaryType="TreeListSummaryItemType.Count" FieldName="Region" />
        <DxTreeListSummaryItem SummaryType="TreeListSummaryItemType.Sum" FieldName="MarchSales" />
        <DxTreeListSummaryItem SummaryType="TreeListSummaryItemType.Custom" FieldName="MarchSales" Name="Custom" />
    </TotalSummary>
</DxTreeList>

@code {
    ITreeList TreeList { get; set; }
    object Data { get; set; }
    protected override void OnInitialized() {
        Data = SalesByRegionDataProvider.GenerateData();
    }
    void TreeList_CustomSummary(TreeListCustomSummaryEventArgs e) {
        switch(e.SummaryStage) {
            case TreeListCustomSummaryStage.Start:
                e.TotalValue = 0m;
                break;
            case TreeListCustomSummaryStage.Calculate:
                if(e.TreeList.IsDataItemSelected(e.DataItem))
                    e.TotalValue = (decimal)e.TotalValue + (decimal)e.GetRowValue("MarchSales");
                break;
        }
    }
    void TreeList_CustomizeSummaryDisplayText(TreeListCustomizeSummaryDisplayTextEventArgs e) {
        if(e.Item.Name == "Custom")
            e.DisplayText = string.Format("Sum of Selected ({0}): {1:c0}", e.TreeList.SelectedDataItems.Count, e.Value);
    }
    void TreeList_SelectedDataItemsChanged(IReadOnlyList<object> newSelection) {
        TreeList.RefreshSummary();
    }
}

Blazor TreeList - Summary for Selection

Implements

See Also