TreeListCustomSummaryEventArgs Class

Contains data for the CustomSummary event.

Assembly : DevExpress.Blazor.v25.2.dll

Declaration

csharp

public class TreeListCustomSummaryEventArgs

Remarks

Use TreeListCustomSummaryEventArgs (TotalValue, FieldValue, and so on) to evaluate the summary value and access other TreeList data.

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();
    }
}

Inheritance

Object TreeListCustomSummaryEventArgs