GridSelectionColumnCellDisplayTemplateContext.SelectEnabled Property

Returns whether the select operation is available for a row from an asynchronous data source.

Namespace: DevExpress.Blazor

Assembly: DevExpress.Blazor.v23.2.dll

NuGet Package: DevExpress.Blazor

Declaration

public bool SelectEnabled { get; }

Property Value

Type	Description
Boolean	true if the select operation is available; otherwise, false.

Remarks

A selection column contains checkboxes or radio buttons depending on the selection mode. You can define the column’s CellDisplayTemplate to display custom select elements in column cells that correspond to data rows.

The select operation can be temporarily unavailable if you bind the Grid to an asynchronous data source (such as a Server Mode data source or GridDevExtremeDataSource). The SelectEnabled context parameter returns false while the select operation cannot be performed. Once this operation becomes available, this parameter returns true.

In the template, use the SelectEnabled parameter to specify the enabled or disabled state for a custom select element. In the same way, you can use the SelectAllEnabled parameter in the selection column’s HeaderTemplate.

Razor

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

<DxGrid Data="InstantFeedbackSource"
        SelectionMode="GridSelectionMode.Single"
        @bind-SelectedDataItem="@SelectedDataItem"
        KeyFieldName="ProductId">
    <Columns>
        <DxGridSelectionColumn>
            <CellDisplayTemplate >
                <DxButton Click="@(() => context.Grid.SelectDataItem(context.DataItem))"
                          Text="Select" RenderStyle="ButtonRenderStyle.Link"
                          Enabled="context.SelectEnabled"/>
            </CellDisplayTemplate>
        </DxGridSelectionColumn>
        <DxGridDataColumn FieldName="ProductName" />
        <DxGridDataColumn FieldName="UnitPrice" />
        <DxGridDataColumn FieldName="QuantityPerUnit" />
        <DxGridDataColumn FieldName="UnitsInStock" />
    </Columns>
</DxGrid>

@code {
    EntityInstantFeedbackSource InstantFeedbackSource { get; set; }
    NorthwindContext Northwind { get; set; }
    object SelectedDataItem { get; set; }

    protected override void OnInitialized() {
        Northwind = NorthwindContextFactory.CreateDbContext();
        InstantFeedbackSource = new EntityInstantFeedbackSource(e => {
            e.KeyExpression = "ProductId";
            e.QueryableSource = Northwind.Products;
        });
    }

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

Employee

using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;

namespace Grid.Northwind {
    public partial class Employee {
        public int EmployeeId { get; set; }
        [Required]
        public string LastName { get; set; }
        [Required]
        public string FirstName { get; set; }
        [Required]
        public string Title { get; set; }
        public string TitleOfCourtesy { get; set; }
        public Nullable<System.DateTime> BirthDate { get; set; }
        [Required]
        [Range(typeof(DateTime), "1/1/2000", "1/1/2020",
        ErrorMessage = "HireDate must be between {1:d} and {2:d}")]
        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";
    }
}

NorthwindContext

using Microsoft.EntityFrameworkCore;
#nullable disable

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

        public NorthwindContext(DbContextOptions<NorthwindContext> options)
            : base(options) {
        }
        // ...
        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<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);
    }
}

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);
});