DxGridSummaryItem Class

A summary item.

Namespace: DevExpress.Blazor

Assembly: DevExpress.Blazor.v21.1.dll

NuGet Package: DevExpress.Blazor

Declaration

public class DxGridSummaryItem :
    ParameterTrackerSettingsComponent,
    IGridSummaryItem

Remarks

The DxGrid allows you to add total and group summaries. Each summary can contain predefined and custom summary items.

Add a Predefined Summary Item

1. Add a DxGridSummaryItem object to the TotalSummary or GroupSummary collection.

2. Specify the summary item’s SummaryType and FieldName properties.

Run Demo: Grid - Total Summary Run Demo: Grid - Group Summary

<DxGrid Data="GridDataSource"
        UnboundColumnData="Grid_CustomUnboundColumnData"
        ShowGroupPanel="true">
    <Columns>
        <DxGridDataColumn FieldName="Order.ShipName" Caption="Contact Name" />
        <DxGridDataColumn FieldName="Order.ShipCountry" Caption="Country" />
        <DxGridDataColumn FieldName="Order.ShipCity" Caption="City" />
        <DxGridDataColumn FieldName="ProductId" DisplayFormat="d" />
        <DxGridDataColumn FieldName="UnitPrice" />
        <DxGridDataColumn FieldName="Quantity" />
        <DxGridDataColumn FieldName="Discount" DisplayFormat="p0" />
        <DxGridDataColumn FieldName="TotalPrice"
                      DisplayFormat="c"
                      UnboundType="GridUnboundColumnType.Decimal" />
    </Columns>
    <GroupSummary>
        <DxGridSummaryItem SummaryType="GridSummaryItemType.Max"
                           ValueDisplayFormat="c"
                           FieldName="UnitPrice" />
    </GroupSummary>
    <TotalSummary>
        <DxGridSummaryItem SummaryType="GridSummaryItemType.Sum" FieldName="TotalPrice" />
    </TotalSummary>
</DxGrid>

Add a Custom Summary Item

1. Add a DxGridSummaryItem object to the TotalSummary or GroupSummary collection and specify the item’s FieldName property.

2. Set the SummaryType property to Custom to use a custom algorithm to calculate a custom summary value.

3. Handle the CustomSummary event to implement the summary calculation algorithm.

The summary calculation consists of three stages:

• Initialization

  The CustomSummary event fires once at this stage. The event’s SummaryStage property value is Start. Use this stage to initialize a summary value (for example, reset internal counters).

• Calculation

  The CustomSummary event fires for each data row in a grid or in a group. The event’s SummaryStage property value is Calculate. Use this stage to calculate a summary value.

  You can set the TotalValueReady property to true at the Initialization stage to skip the Calculation stage and calculate a custom summary at the Initialization or Finalization stage.

• Finalization

  The CustomSummary event fires once at this stage. The event’s SummaryStage property value is Finalize. Use this stage to assign the calculated summary value to the TotalValue property.

In the following example, the custom summary calculates the number of records whose Unit Price field values are less than 20.

Run Demo: Grid - Custom Summary

<DxGrid Data="GridDataSource"
        UnboundColumnData="Grid_CustomUnboundColumnData"
        CustomizeSummaryDisplayText="Grid_CustomizeSummaryDisplayText"
        CustomSummary="Grid_CustomSummary">
    <Columns>
        <DxGridDataColumn FieldName="ProductId" DisplayFormat="d" />
        <DxGridDataColumn FieldName="UnitPrice" />
        <DxGridDataColumn FieldName="Quantity" />
        <DxGridDataColumn FieldName="Discount" DisplayFormat="p0" />
        <DxGridDataColumn FieldName="TotalPrice"
                      DisplayFormat="c"
                      UnboundType="GridUnboundColumnType.Decimal" />
    </Columns>
    <TotalSummary>
        <DxGridSummaryItem SummaryType="GridSummaryItemType.Sum" FieldName="TotalPrice" />
        <DxGridSummaryItem SummaryType="GridSummaryItemType.Custom" Name="Custom" FieldName="ProductId" />
    </TotalSummary>
</DxGrid>
@* ... *@
@code {
    object GridDataSource { get; set; }
    int totalCount;

    protected override void OnInitialized() {
        GridDataSource = Northwind.OrderDetails
            .Include(i => i.Order)
            .Include(i => i.Product)
            .ToList();
    }

    void Grid_CustomSummary(GridCustomSummaryEventArgs e) {
        if (e.SummaryStage == GridCustomSummaryStage.Start)
            totalCount = 0;
        else if (e.SummaryStage == GridCustomSummaryStage.Calculate) {
            if (Convert.ToInt16(e.GetValue("UnitPrice")) < 20)
                totalCount++;
        }
        else if (e.SummaryStage == GridCustomSummaryStage.Finalize)
            e.TotalValue = totalCount;
    }

    void Grid_CustomizeSummaryDisplayText(GridCustomizeSummaryDisplayTextEventArgs e) {
        if (e.Item.Name == "Custom")
            e.DisplayText = string.Format("Count (Unit Price < 20): {0}", e.Value);
    }
    @* ... *@
}

Note

The Grid does not support custom summary calculation when you use a GridDevExtremeDataSource.

Format a Summary

The summary’s default display text can contain the summary function, summary value and a name of a column whose values are summarized. What to display in the summary depends on a summary function and a column under which the summary is located.

Razor

@using Grid.Northwind
@inject NorthwindContext Northwind

<DxGrid Data="GridDataSource"
        ShowGroupPanel="true"
        UnboundColumnData="Grid_CustomUnboundColumnData">
    <Columns>
        <DxGridDataColumn FieldName="Order.ShipCountry" Caption="Country" />
        <DxGridDataColumn FieldName="Order.ShipCity" Caption="City" />
        <DxGridDataColumn FieldName="ProductId" DisplayFormat="d" />
        <DxGridDataColumn FieldName="UnitPrice" />
        <DxGridDataColumn FieldName="Quantity" />
        <DxGridDataColumn FieldName="Discount" DisplayFormat="p0" />
        <DxGridDataColumn FieldName="TotalPrice"
                      DisplayFormat="c0"
                      UnboundType="GridUnboundColumnType.Decimal" />
    </Columns>
    <TotalSummary>
        <DxGridSummaryItem SummaryType="GridSummaryItemType.Sum" FieldName="TotalPrice" />
        <DxGridSummaryItem SummaryType="GridSummaryItemType.Sum" FieldName="Quantity" FooterColumnName="TotalPrice" />
    </TotalSummary>
    <GroupSummary>
        <DxGridSummaryItem SummaryType="GridSummaryItemType.Count" FieldName="ProductId" />
    </GroupSummary>
</DxGrid>
@* ... *@
@code {

    object GridDataSource { get; set; }

    protected override void OnInitialized()
    {
        GridDataSource = Northwind.OrderDetails
            .Include(i => i.Order)
            .Include(i => i.Product)
            .ToList();
    }
    @* ... *@
    void Grid_CustomUnboundColumnData(GridUnboundColumnDataEventArgs e)
    {
        if (e.FieldName == "TotalPrice")
        {
            var UnitPrice = Convert.ToDecimal(e.GetRowValue("UnitPrice"));
            var Quantity = Convert.ToDecimal(e.GetRowValue("Quantity"));
            var Discount = Convert.ToDecimal(e.GetRowValue("Discount"));

            e.Value = Quantity * UnitPrice * (1 - Discount);
        }
    }
}

OrderDetails

using System;
using System.Collections.Generic;

#nullable disable

namespace Grid.Northwind {
    public partial class OrderDetail {
        public int OrderId { get; set; }
        public int ProductId { get; set; }
        public decimal UnitPrice { get; set; }
        public short Quantity { get; set; }
        public float Discount { get; set; }

        public virtual Order Order { get; set; }
        public virtual Product Product { get; set; }
    }
}

Order

using System;
using System.Collections.Generic;

#nullable disable

namespace Grid.Northwind {
    public partial class Order {
        public Order() {
            OrderDetails = new HashSet<OrderDetail>();
        }

        public int OrderId { get; set; }
        public string CustomerId { get; set; }
        public int? EmployeeId { get; set; }
        public DateTime? OrderDate { get; set; }
        public DateTime? RequiredDate { get; set; }
        public DateTime? ShippedDate { get; set; }
        public int? ShipVia { get; set; }
        public decimal? Freight { get; set; }
        public string ShipName { get; set; }
        public string ShipAddress { get; set; }
        public string ShipCity { get; set; }
        public string ShipRegion { get; set; }
        public string ShipPostalCode { get; set; }
        public string ShipCountry { get; set; }

        public virtual Customer Customer { get; set; }
        public virtual Shipper ShipViaNavigation { get; set; }
        public virtual ICollection<OrderDetail> OrderDetails { get; set; }
    }
}

NorthwindContext

using Microsoft.EntityFrameworkCore;
#nullable disable

namespace Grid.Northwind {
    public partial class NorthwindContext : DbContext {
        public NorthwindContext() {
        }

        public NorthwindContext(DbContextOptions<NorthwindContext> options)
            : base(options) {
        }
        // ...
        public virtual DbSet<Order> Orders { get; set; }
        public virtual DbSet<OrderDetail> OrderDetails { get; set; }
        // ...
        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder) {
            if(!optionsBuilder.IsConfigured) {
                optionsBuilder.UseSqlServer("Server=.\\sqlexpress;Database=Northwind;Integrated Security=true");
            }
        }
        // ...
        protected override void OnModelCreating(ModelBuilder modelBuilder) {
        // ...
            modelBuilder.Entity<Order>(entity => {
                entity.HasIndex(e => e.CustomerId, "CustomerID");
                entity.HasIndex(e => e.CustomerId, "CustomersOrders");
                entity.HasIndex(e => e.EmployeeId, "EmployeeID");
                entity.HasIndex(e => e.EmployeeId, "EmployeesOrders");
                entity.HasIndex(e => e.OrderDate, "OrderDate");
                entity.HasIndex(e => e.ShipPostalCode, "ShipPostalCode");
                entity.HasIndex(e => e.ShippedDate, "ShippedDate");
                entity.HasIndex(e => e.ShipVia, "ShippersOrders");
                entity.Property(e => e.OrderId).HasColumnName("OrderID");
                entity.Property(e => e.CustomerId)
                    .HasMaxLength(5)
                    .HasColumnName("CustomerID")
                    .IsFixedLength(true);
                entity.Property(e => e.EmployeeId).HasColumnName("EmployeeID");
                entity.Property(e => e.Freight)
                    .HasColumnType("money")
                    .HasDefaultValueSql("((0))");
                entity.Property(e => e.OrderDate).HasColumnType("datetime");
                entity.Property(e => e.RequiredDate).HasColumnType("datetime");
                entity.Property(e => e.ShipAddress).HasMaxLength(60);
                entity.Property(e => e.ShipCity).HasMaxLength(15);
                entity.Property(e => e.ShipCountry).HasMaxLength(15);
                entity.Property(e => e.ShipName).HasMaxLength(40);
                entity.Property(e => e.ShipPostalCode).HasMaxLength(10);
                entity.Property(e => e.ShipRegion).HasMaxLength(15);
                entity.Property(e => e.ShippedDate).HasColumnType("datetime");
                entity.HasOne(d => d.Customer)
                    .WithMany(p => p.Orders)
                    .HasForeignKey(d => d.CustomerId)
                    .HasConstraintName("FK_Orders_Customers");
                entity.HasOne(d => d.ShipViaNavigation)
                    .WithMany(p => p.Orders)
                    .HasForeignKey(d => d.ShipVia)
                    .HasConstraintName("FK_Orders_Shippers");
            });
            modelBuilder.Entity<OrderDetail>(entity => {
                entity.HasKey(e => new { e.OrderId, e.ProductId })
                    .HasName("PK_Order_Details");
                entity.ToTable("Order Details");
                entity.HasIndex(e => e.OrderId, "OrderID");
                entity.HasIndex(e => e.OrderId, "OrdersOrder_Details");
                entity.HasIndex(e => e.ProductId, "ProductID");
                entity.HasIndex(e => e.ProductId, "ProductsOrder_Details");
                entity.Property(e => e.OrderId).HasColumnName("OrderID");
                entity.Property(e => e.ProductId).HasColumnName("ProductID");
                entity.Property(e => e.Quantity).HasDefaultValueSql("((1))");
                entity.Property(e => e.UnitPrice).HasColumnType("money");
                entity.HasOne(d => d.Order)
                    .WithMany(p => p.OrderDetails)
                    .HasForeignKey(d => d.OrderId)
                    .OnDelete(DeleteBehavior.ClientSetNull)
                    .HasConstraintName("FK_Order_Details_Orders");
                entity.HasOne(d => d.Product)
                    .WithMany(p => p.OrderDetails)
                    .HasForeignKey(d => d.ProductId)
                    .OnDelete(DeleteBehavior.ClientSetNull)
                    .HasConstraintName("FK_Order_Details_Products");
            });
            // ...
        }
        // ...
    }
}

Startup

public class Startup {
// ...
    public void ConfigureServices(IServiceCollection services) {
    // ...
        services.AddEntityFrameworkSqlServer();
        services.AddDbContext<NorthwindContext>((sp, options) => {
            var env = sp.GetRequiredService<IWebHostEnvironment>();
            var dbPath = Path.Combine(env.ContentRootPath, "Northwind-5e44b51f.mdf");
            options.UseSqlServer("Server=(localdb)\\MSSQLLocalDB;Integrated Security=true;AttachDbFileName=" + dbPath);
        });
    }
    // ...
}

The following API members allows you to format the summary’s value and display text:

• ValueDisplayFormat property
• CustomizeSummaryDisplayText event
• CustomizeGroupValueDisplayText event

Razor

<DxGrid Data="GridDataSource"
        UnboundColumnData="Grid_CustomUnboundColumnData"
        CustomizeSummaryDisplayText="Grid_CustomizeSummaryDisplayText"
        ShowGroupPanel="true">
    <Columns>
        <DxGridDataColumn FieldName="Order.ShipCountry" Caption="Country" />
        <DxGridDataColumn FieldName="Order.ShipCity" Caption="City" />
        <DxGridDataColumn FieldName="ProductId" />
        <DxGridDataColumn FieldName="UnitPrice" />
        <DxGridDataColumn FieldName="Quantity" />
        <DxGridDataColumn FieldName="Discount" />
        <DxGridDataColumn FieldName="TotalPrice"
                      UnboundType="GridUnboundColumnType.Decimal" />
    </Columns>
    <TotalSummary>
        <DxGridSummaryItem SummaryType="GridSummaryItemType.Sum"
                           FieldName="TotalPrice"
                           ValueDisplayFormat="C0"/>
        <DxGridSummaryItem SummaryType="GridSummaryItemType.Count"
                           Name="CustomTotal"
                           FieldName="ProductId"
                           FooterColumnName="TotalPrice"/>
    </TotalSummary>
    <GroupSummary>
        <DxGridSummaryItem SummaryType="GridSummaryItemType.Count"
                           Name="CustomGroup"
                           FieldName="ProductId" />
    </GroupSummary>
</DxGrid>
@* ... *@
@code {

    object GridDataSource { get; set; }

    protected override void OnInitialized()
    {
        GridDataSource = Northwind.OrderDetails
            .Include(i => i.Order)
            .Include(i => i.Product)
            .ToList();
    }

    void Grid_CustomizeSummaryDisplayText(GridCustomizeSummaryDisplayTextEventArgs e)
    {
        if (e.Item.Name == "CustomTotal") {
            e.DisplayText = string.Format("Total Rows: {0:N0}", e.Value);
        }
        else if (e.Item.Name == "CustomGroup") {
            e.DisplayText = string.Format("Rows in Group: {0}", e.Value);
        }
    }

    void Grid_CustomUnboundColumnData(GridUnboundColumnDataEventArgs e)
    {
        if (e.FieldName == "TotalPrice")
        {
            var UnitPrice = Convert.ToDecimal(e.GetRowValue("UnitPrice"));
            var Quantity = Convert.ToDecimal(e.GetRowValue("Quantity"));
            var Discount = Convert.ToDecimal(e.GetRowValue("Discount"));

            e.Value = Quantity * UnitPrice * (1 - Discount);
        }
    }
}

OrderDetails

using System;
using System.Collections.Generic;

#nullable disable

namespace Grid.Northwind {
    public partial class OrderDetail {
        public int OrderId { get; set; }
        public int ProductId { get; set; }
        public decimal UnitPrice { get; set; }
        public short Quantity { get; set; }
        public float Discount { get; set; }

        public virtual Order Order { get; set; }
        public virtual Product Product { get; set; }
    }
}

Order

using System;
using System.Collections.Generic;

#nullable disable

namespace Grid.Northwind {
    public partial class Order {
        public Order() {
            OrderDetails = new HashSet<OrderDetail>();
        }

        public int OrderId { get; set; }
        public string CustomerId { get; set; }
        public int? EmployeeId { get; set; }
        public DateTime? OrderDate { get; set; }
        public DateTime? RequiredDate { get; set; }
        public DateTime? ShippedDate { get; set; }
        public int? ShipVia { get; set; }
        public decimal? Freight { get; set; }
        public string ShipName { get; set; }
        public string ShipAddress { get; set; }
        public string ShipCity { get; set; }
        public string ShipRegion { get; set; }
        public string ShipPostalCode { get; set; }
        public string ShipCountry { get; set; }

        public virtual Customer Customer { get; set; }
        public virtual Shipper ShipViaNavigation { get; set; }
        public virtual ICollection<OrderDetail> OrderDetails { get; set; }
    }
}

NorthwindContext

using Microsoft.EntityFrameworkCore;
#nullable disable

namespace Grid.Northwind {
    public partial class NorthwindContext : DbContext {
        public NorthwindContext() {
        }

        public NorthwindContext(DbContextOptions<NorthwindContext> options)
            : base(options) {
        }
        // ...
        public virtual DbSet<Order> Orders { get; set; }
        public virtual DbSet<OrderDetail> OrderDetails { get; set; }
        // ...
        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder) {
            if(!optionsBuilder.IsConfigured) {
                optionsBuilder.UseSqlServer("Server=.\\sqlexpress;Database=Northwind;Integrated Security=true");
            }
        }
        // ...
        protected override void OnModelCreating(ModelBuilder modelBuilder) {
        // ...
            modelBuilder.Entity<Order>(entity => {
                entity.HasIndex(e => e.CustomerId, "CustomerID");
                entity.HasIndex(e => e.CustomerId, "CustomersOrders");
                entity.HasIndex(e => e.EmployeeId, "EmployeeID");
                entity.HasIndex(e => e.EmployeeId, "EmployeesOrders");
                entity.HasIndex(e => e.OrderDate, "OrderDate");
                entity.HasIndex(e => e.ShipPostalCode, "ShipPostalCode");
                entity.HasIndex(e => e.ShippedDate, "ShippedDate");
                entity.HasIndex(e => e.ShipVia, "ShippersOrders");
                entity.Property(e => e.OrderId).HasColumnName("OrderID");
                entity.Property(e => e.CustomerId)
                    .HasMaxLength(5)
                    .HasColumnName("CustomerID")
                    .IsFixedLength(true);
                entity.Property(e => e.EmployeeId).HasColumnName("EmployeeID");
                entity.Property(e => e.Freight)
                    .HasColumnType("money")
                    .HasDefaultValueSql("((0))");
                entity.Property(e => e.OrderDate).HasColumnType("datetime");
                entity.Property(e => e.RequiredDate).HasColumnType("datetime");
                entity.Property(e => e.ShipAddress).HasMaxLength(60);
                entity.Property(e => e.ShipCity).HasMaxLength(15);
                entity.Property(e => e.ShipCountry).HasMaxLength(15);
                entity.Property(e => e.ShipName).HasMaxLength(40);
                entity.Property(e => e.ShipPostalCode).HasMaxLength(10);
                entity.Property(e => e.ShipRegion).HasMaxLength(15);
                entity.Property(e => e.ShippedDate).HasColumnType("datetime");
                entity.HasOne(d => d.Customer)
                    .WithMany(p => p.Orders)
                    .HasForeignKey(d => d.CustomerId)
                    .HasConstraintName("FK_Orders_Customers");
                entity.HasOne(d => d.ShipViaNavigation)
                    .WithMany(p => p.Orders)
                    .HasForeignKey(d => d.ShipVia)
                    .HasConstraintName("FK_Orders_Shippers");
            });
            // ...
            OnModelCreatingPartial(modelBuilder);
        }
        // ...
    }
}

Startup

public class Startup {
// ...
    public void ConfigureServices(IServiceCollection services) {
    // ...
        services.AddEntityFrameworkSqlServer();
        services.AddDbContext<NorthwindContext>((sp, options) => {
            var env = sp.GetRequiredService<IWebHostEnvironment>();
            var dbPath = Path.Combine(env.ContentRootPath, "Northwind-5e44b51f.mdf");
            options.UseSqlServer("Server=(localdb)\\MSSQLLocalDB;Integrated Security=true;AttachDbFileName=" + dbPath);
        });
    }
    // ...
}

Implements

IComponent

IHandleEvent

IHandleAfterRender

IDisposable

IGridSummaryItem

Inheritance

Object

ComponentBase

DevExpress.Blazor.Internal.ParameterTrackerSettingsComponent

DxGridSummaryItem