DxGridDataColumn Class

A DxGrid‘s data column.

Namespace: DevExpress.Blazor

Assembly: DevExpress.Blazor.v23.2.dll

NuGet Package: DevExpress.Blazor

Declaration

public class DxGridDataColumn :
    DxGridColumn,
    IGridDataColumn,
    IGridColumn,
    IParameterTrackerSettingsOwner

Remarks

The DxGrid supports bound and unbound data columns. Bound columns get their data from the bound data source. Unbound columns are not bound to any data source field and should be populated manually.

Watch Video: Grid - Column Types, Column Resize and Visibility

Create a Bound Column

Add a DxGridDataColumn object to the Columns collection and specify the FieldName property. This property binds the column to a data field.

Razor

@using Microsoft.EntityFrameworkCore
@inject IDbContextFactory<NorthwindContext> NorthwindContextFactory
@implements IDisposable

<DxGrid Data="GridDataSource">
    <Columns>
        <DxGridDataColumn FieldName="OrderId" Caption="Order ID" DisplayFormat="d" />
        <DxGridDataColumn FieldName="Order.OrderDate" DisplayFormat="d" Caption="Order Date" />
        <DxGridDataColumn FieldName="Order.ShipName" Caption="Ship Name" />
        <DxGridDataColumn FieldName="Discount" DisplayFormat="p0" />
    </Columns>
</DxGrid>

@code {

    object GridDataSource { get; set; }
    NorthwindContext Northwind { get; set; }

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

    public void Dispose() {
        Northwind?.Dispose();
    }
}

OrderDetail

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; }
    }
}

NorthwindContext

using Microsoft.EntityFrameworkCore;
#nullable disable

namespace Grid.Northwind {
    public partial class NorthwindContext : DbContext {

        public NorthwindContext(DbContextOptions<NorthwindContext> options)
            : base(options) {
        }
        // ...
        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.HasAnnotation("Relational:Collation", "SQL_Latin1_General_CP1_CI_AS");
            // ...
            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");
            });
            // ...
            OnModelCreatingPartial(modelBuilder);
        }

        partial void OnModelCreatingPartial(ModelBuilder modelBuilder);
    }
}

Program.cs

using Microsoft.EntityFrameworkCore;
// ...
builder.Services.AddDbContextFactory<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);
});

Run Demo: Grid - Data Binding View Example: Grid - Implement Cascading Combo Boxes

Create an Unbound Column

Add a DxGridDataColumn object to the Columns collection and and set up the following properties:

UnboundType

Indicates that the column is unbound and specifies its data type.

FieldName

Specifies a unique name that should not match field names in the Grid’s data source.

You can use the following API to fill an unbound column with data:

UnboundExpression

Specifies an expression to evaluate column values. An expression can consist of field names, constants, operators, and functions.

UnboundColumnData

Allows you to implement custom logic or obtain column values from a custom/external data source.

<DxGrid Data="forecasts" UnboundColumnData="Grid_CustomUnboundColumnData">
    <Columns>
        <DxGridDataColumn FieldName="Date" Caption="Date" />
        <DxGridDataColumn FieldName="TemperatureC" Caption="@("Temperature (\x2103)")" />
        <DxGridDataColumn FieldName="TemperatureF" Caption="@("Temperature (\x2109)")"
                          UnboundType="GridUnboundColumnType.Decimal"
                          UnboundExpression="32 + [TemperatureC] / 0.5556" />
        <DxGridDataColumn FieldName="Summary"
                          UnboundType="GridUnboundColumnType.String" />
    </Columns>
</DxGrid>

@code {
    private WeatherForecast[]? forecasts;

    protected override async Task OnInitializedAsync() {
        forecasts = await ForecastService.GetForecastAsync(DateTime.Now);
    }

    void Grid_CustomUnboundColumnData(GridUnboundColumnDataEventArgs e) {
        if (e.FieldName == "Summary") {
            int temperature = Convert.ToInt32(e.GetRowValue("TemperatureC"));
            e.Value = GetTemperatureString(temperature);
        }
    }

    static string GetTemperatureString(int value) {
        if (value < -10)
            return "Cool";
        if (value >= -10 && value < 5)
            return "Chilly";
        if (value >= 5 && value < 15)
            return "Warm";
        return "Hot";
    }
}

View Example: Create and Edit Unbound Columns

Limitations

• When you use a Server Mode data source, the Grid does not support unbound columns whose values are populated in the UnboundColumnData event handler. You can create unbound columns whose values are calculated based on the UnboundExpression.
• When you use a GridDevExtremeDataSource, the Grid does not support unbound columns.

Implements

IComponent

IHandleEvent

IHandleAfterRender

IDisposable

IGridDataColumn

IGridColumn

Inheritance

Object

ComponentBase

DevExpress.Blazor.Internal.BranchedRenderComponent

DevExpress.Blazor.Internal.ParameterTrackerSettingsComponent

DxGridColumn

DxGridDataColumn