[Parameter]
public RenderFragment<GridDataColumnCellEditTemplateContext> CellEditTemplate { get; set; }

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

<DxGrid @ref="Grid"
        Data="Data"
        KeyFieldName="EmployeeId"
        EditMode="GridEditMode.EditRow">
    <Columns>
        <DxGridCommandColumn />
        <DxGridDataColumn FieldName="FirstName" />
        <DxGridDataColumn FieldName="LastName" />
        <DxGridDataColumn FieldName="Title" />
        <DxGridDataColumn FieldName="HireDate">
            <CellEditTemplate>
                @{
                    var employee = (Employee)context.EditModel;
                }
                <DxDateEdit @bind-Date="@employee.HireDate">
                    <Buttons>
                        <DxEditorButton IconCssClass="editor-icon editor-icon-chevron-left-small"
                                        Tooltip="Previous date"
                                        Position="@EditorButtonPosition.Left"
                                        Click="@(_ => employee.HireDate = employee.HireDate?.AddDays(-1))" />
                        <DxEditorButton IconCssClass="editor-icon editor-icon-chevron-right-small"
                                        Tooltip="Next date"
                                        Position="@EditorButtonPosition.Right"
                                        Click="@(_ => employee.HireDate = employee.HireDate?.AddDays(1))" />
                    </Buttons>
                </DxDateEdit>
            </CellEditTemplate>
        </DxGridDataColumn>
    </Columns>
</DxGrid>

@code {
    IEnumerable<object> Data { get; set; }
    NorthwindContext Northwind { get; set; }
    DateTime DateTimeValue { get; set; } = DateTime.Today;
    bool CalendarVisible { get; set; }

    void OnChangeDayButtonClick(bool isAdd) {
        CalendarVisible = false;
        DateTimeValue = DateTimeValue.AddDays(isAdd ? 1 : -1);
    }
    // ...
}

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 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 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";
    }
}

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);
    }
}

using Microsoft.EntityFrameworkCore;
// ...
builder.Services.AddDbContextFactory<NorthwindContext>((sp, options) => {
    var env = sp.GetRequiredService<IWebHostEnvironment>();
    var dbPath = Path.Combine(env.ContentRootPath, "Northwind.mdf");
    options.UseSqlServer("Server=(localdb)\\MSSQLLocalDB;Integrated Security=true;AttachDbFileName=" + dbPath);
});

.editor-icon {
    width: 1rem;
    height: 1rem;
    background-size: contain;
    -webkit-mask-repeat: no-repeat;
    mask-repeat: no-repeat;
    background-position: center center;
    background-color: currentColor;
    opacity: 0.7;
}

.editor-icon-chevron-right-small {
    -webkit-mask-image: url("../images/icons/chevron-right-small.svg");
    mask-image: url("../images/icons/chevron-right-small.svg");
}

.editor-icon-chevron-left-small {
    -webkit-mask-image: url("../images/icons/chevron-left-small.svg");
    mask-image: url("../images/icons/chevron-left-small.svg");
}