DxComboBoxSettings.Columns Property

Allows you to add columns to the combo box editor.

Namespace: DevExpress.Blazor

Assembly: DevExpress.Blazor.v24.1.dll

NuGet Package: DevExpress.Blazor

Declaration

[Parameter]
public RenderFragment Columns { get; set; }

Property Value

Type	Description
RenderFragment	A collection of columns (UI fragments).

Remarks

Place DxListEditorColumn objects in the <Columns> tag to display multiple columns in the combo box editor’s drop-down window. Set the object’s FieldName property to bind the column to data. The following optional properties of the DxListEditorColumn class allow you to customize column appearance:

Caption

Specifies the column’s caption text.

ColumnCellDisplayTemplate

Specifies a template used to display column cells in the combo box editor.

Visible

Specifies the column’s visibility.

VisibleIndex

Specifies the column’s visible index.

Width

Specifies the column’s width.

The EditFormat property allows you to format the edit value of a multi-column combo box.

The following code snippet adds three columns to the combo box editor and formats its edit value:

Razor

@inject IDbContextFactory<NorthwindContext> NorthwindContextFactory

<DxGrid Data="Orders"
        EditMode="GridEditMode.EditRow">
    <Columns>
        <DxGridCommandColumn />
        <DxGridDataColumn FieldName="EmployeeId" Caption="Employee" Width="20%">
            <EditSettings>
                <DxComboBoxSettings Data="Employees"
                                    TextFieldName="LastName"
                                    ValueFieldName="EmployeeId"
                                    EditFormat="{1} {2}" >
                    <Columns>
                        <DxListEditorColumn FieldName="EmployeeId" Caption="Id" Width="30px" />
                        <DxListEditorColumn FieldName="FirstName" Caption="Name" />
                        <DxListEditorColumn FieldName="LastName" Caption="Surname" />
                    </Columns>
                </DxComboBoxSettings>
            </EditSettings>
        </DxGridDataColumn>
        <DxGridDataColumn FieldName="ShippedDate" />
        <DxGridDataColumn FieldName="ShipCountry" />
        <DxGridDataColumn FieldName="ShipCity" />
        <DxGridDataColumn FieldName="ShipName" Width="20%" />
    </Columns>
</DxGrid>


@code {
    NorthwindContext Northwind { get; set; }
    List<Order> Orders { get; set; }
    List<Employee> Employees { get; set; }

    protected override async Task OnInitializedAsync() {
        Northwind = NorthwindContextFactory.CreateDbContext();
        Orders = await Northwind.Orders.ToListAsync();
        Employees = await Northwind.Employees.ToListAsync();
    }

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

NorthwindContext

using Microsoft.EntityFrameworkCore;
#nullable disable

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

        public NorthwindContext(DbContextOptions<NorthwindContext> options)
            : base(options) {
        }
        // ...
        public virtual DbSet<Order> Orders { get; set; }
        public virtual DbSet<Employee> Employees { 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<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");
            });
            modelBuilder.Entity<Employee>(entity => {
                entity.HasIndex(e => e.EmployeeId, "EmployeeId");
                entity.HasIndex(e => e.LastName, "LastName");
                entity.HasIndex(e => e.FirstName, "FirstName");
                entity.HasIndex(e => e.Title, "Title");
                entity.HasIndex(e => e.BirthDate, "BirthDate");
                entity.HasIndex(e => e.HireDate, "HireDate");
                entity.HasIndex(e => e.Notes, "Notes");
            });
            // ...
            OnModelCreatingPartial(modelBuilder);
        }

        partial void OnModelCreatingPartial(ModelBuilder modelBuilder);
    }
}

Order.cs

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; }
}

Employee.cs

public partial class Employee {
        public int EmployeeId { get; set; }
        public string LastName { get; set; }
        public string FirstName { get; set; }
        public string Title { get; set; }
        public string TitleOfCourtesy { get; set; }
        public Nullable<System.DateTime> BirthDate { get; set; }
        public Nullable<System.DateTime> HireDate { get; set; }
        public string Address { get; set; }
        public string City { get; set; }
        public string Region { get; set; }
        public string PostalCode { get; set; }
        public string Country { get; set; }
        public string HomePhone { get; set; }
        public string Extension { get; set; }
        public byte[] Photo { get; set; }
        public string Notes { get; set; }
        public Nullable<int> ReportsTo { get; set; }
        public string PhotoPath { get; set; }
        public virtual ICollection<Order> Orders { get; set; }
        public string Text => $"{FirstName} {LastName} ({Title})";
        public string ImageFileName => $"Employees/{EmployeeId}.jpg";
    }

To add/remove columns to/from the combo box at runtime, use the IComboBoxSettings.Columns property.

Implements

Columns