blazor-devexpress-dot-blazor-bd23d27e.md
An interface that defines a Grid summary item‘s API members (properties and methods).
Namespace : DevExpress.Blazor
Assembly : DevExpress.Blazor.v25.2.dll
NuGet Package : DevExpress.Blazor
public interface IGridSummaryItem
The following members return IGridSummaryItem objects:
We recommend that you use the IGridSummaryItem interface when you access a Grid summary item’s API members in any of the following cases:
@ref attribute to reference a Grid summary item. For example, you set or change values of the Grid summary item’s parameters outside the markup.Item object from summary templates or event handlers.In all other cases, bind your data to a summary item’s parameters.
The following code snippet handles the CustomizeSummaryDisplayText event to customize a custom summary item‘s text. The event’s Item argument (which returns an IGridSummaryItem object) provides access to the processed summary item.
Run Demo: Grid - Custom Summary
<DxGrid @ref="Grid"
Data="@Data"
SelectedDataItems="@SelectedDataItems"
SelectedDataItemsChanged="Grid_SelectedDataItemsChanged"
CustomSummary="Grid_CustomSummary"
CustomizeSummaryDisplayText="Grid_CustomizeSummaryDisplayText">
<Columns>
<DxGridSelectionColumn />
<DxGridDataColumn FieldName="OrderId" Caption="Order ID"/>
<DxGridDataColumn FieldName="CustomerId" Caption="Customer">
<EditSettings>
<DxComboBoxSettings Data="Customers" ValueFieldName="CustomerId" TextFieldName="ContactName"/>
</EditSettings>
</DxGridDataColumn>
<DxGridDataColumn FieldName="OrderDate" />
<DxGridDataColumn FieldName="ShipCountry" />
<DxGridDataColumn FieldName="ShipCity" />
<DxGridDataColumn FieldName="ShippedDate" />
<DxGridDataColumn FieldName="Total" DisplayFormat="c" />
</Columns>
<TotalSummary>
<DxGridSummaryItem SummaryType="GridSummaryItemType.Custom" Name="Custom" FieldName="Total" />
<DxGridSummaryItem SummaryType="GridSummaryItemType.Sum"
FieldName="Total"
DisplayText="Grand Total: {0}"
ValueDisplayFormat="c0" />
</TotalSummary>
</DxGrid>
@code {
IEnumerable<object> Data { get; set; }
IReadOnlyList<Customer> Customers { get; set; }
IReadOnlyList<object> SelectedDataItems { get; set; }
IGrid Grid { get; set; }
@* ... *@
void Grid_CustomSummary(GridCustomSummaryEventArgs e) {
switch(e.SummaryStage) {
case GridCustomSummaryStage.Start:
e.TotalValue = 0m;
break;
case GridCustomSummaryStage.Calculate:
if(e.Grid.IsDataItemSelected(e.DataItem))
e.TotalValue = (decimal)e.TotalValue + (decimal)e.GetRowValue("Total");
break;
}
}
void Grid_CustomizeSummaryDisplayText(GridCustomizeSummaryDisplayTextEventArgs e) {
if(e.Item.Name == "Custom")
e.DisplayText = string.Format("Sum of Selected ({0}): {1:c0}", SelectedDataItems.Count, e.Value);
}
void Grid_SelectedDataItemsChanged(IReadOnlyList<object> newSelection) {
SelectedDataItems = newSelection;
Grid.RefreshSummary();
}
}
See Also