TreeListCustomSummaryStage Enum

Lists values that specify possible stages of the summary calculation.

Namespace: DevExpress.Blazor

Assembly: DevExpress.Blazor.v25.1.dll

NuGet Package: DevExpress.Blazor

Declaration

C#

public enum TreeListCustomSummaryStage

Members

Name	Description
Start	The CustomSummary event fires once at this stage before TreeList rows are processed. This allows you to initialize a summary value.
Calculate	The CustomSummary event fires for each data row in a TreeList. You can calculate a summary value at this stage.
Finalize	The CustomSummary event fires once at this stage after TreeList rows are processed. At this stage, you can finalize the summary calculation.

Related API Members

The following properties accept/return TreeListCustomSummaryStage values:

• TreeListCustomSummaryEventArgs.SummaryStage

Remarks

The following code sample calculates the sum of March Sales values of selected TreeList rows:

Run Demo: Custom Summary

Razor

@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();
    }
}