DxGrid.ShowRowDeleteConfirmation(Int32) Method

Displays the delete confirmation dialog for the specified row.

Namespace: DevExpress.Blazor

Assembly: DevExpress.Blazor.v21.2.dll

NuGet Package: DevExpress.Blazor

Declaration

public void ShowRowDeleteConfirmation(
    int visibleIndex
)

Parameters

Name	Type	Description
visibleIndex	Int32	The row’s visible index.

Remarks

The Grid allows users to add, edit, and delete its data rows.

Tip

For information on how to enable data editing, refer to the following topic: Edit Data and Validate Input.

The Grid supports the DxGridCommandColumn that contains the predefined New, Edit, and Delete command buttons. Once a user clicks the Delete button, the delete confirmation dialog appears.

You can also create custom command elements inside or outside the Grid. Handle an element’s click event and call the ShowRowDeleteConfirmation method to display the delete confirmation dialog for the specified row. The DataItemDeleting event fires when a user confirms the delete operation. Handle this event to check user access permissions and delete the data item from the underlying data source.

The Grid also includes the following edit-related methods:

• ShowDataItemDeleteConfirmation displays the delete confirmation dialog for the specified data item.
• StartEditRowAsync and StartEditDataItemAsync display the edit form used to modify the specified row or data item.
• StartEditNewRowAsync displays the edit form used to create a new data row.

The following example creates buttons used to edit and delete a row whose visible index is 0:

Razor

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

<DxGrid Data="GridDataSource"
        EditModelSaving="OnEditModelSaving"
        DataItemDeleting="OnDataItemDeleting"
        KeyFieldName="EmployeeId"
        @ref="MyGrid">
    <Columns>
        <DxGridCommandColumn Width="150" />
        <DxGridDataColumn FieldName="FirstName" />
        <DxGridDataColumn FieldName="LastName" />
        <DxGridDataColumn FieldName="Title" />
        <DxGridDataColumn FieldName="HireDate" />
    </Columns>
    <EditFormTemplate Context="editFormContext">
        @{
            var employee = (Employee)editFormContext.EditModel;
        }
        <DxFormLayout>
            <DxFormLayoutItem Caption="First Name:">
                <DxTextBox @bind-Text="@employee.FirstName" />
            </DxFormLayoutItem>
            <DxFormLayoutItem Caption="Last Name:">
                <DxTextBox @bind-Text="@employee.LastName" />
            </DxFormLayoutItem>
            <DxFormLayoutItem Caption="Title:">
                <DxTextBox @bind-Text="@employee.Title" />
            </DxFormLayoutItem>
            <DxFormLayoutItem Caption="Hire Date:">
                <DxDateEdit @bind-Date="@employee.HireDate" />
            </DxFormLayoutItem>
        </DxFormLayout>
    </EditFormTemplate>
</DxGrid>

<br />
<DxButton Click="() => MyGrid.StartEditRowAsync(0)">Edit First Row</DxButton>
<DxButton Click="() => MyGrid.ShowRowDeleteConfirmation(0)">Delete First Row</DxButton>


@code {
    IEnumerable<object> GridDataSource { get; set; }
    NorthwindContext Northwind { get; set; }
    IGrid MyGrid { get; set; }

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

    async Task OnEditModelSaving(GridEditModelSavingEventArgs e) {
        var editModel = (Employee)e.EditModel;
        // Re-query a data item from the database.
        var dataItem = e.IsNew ? new Employee() : Northwind.Employees.Find(editModel.EmployeeId);
        // Assign changes from the edit model to the data item.
        if (dataItem != null) {
            dataItem.FirstName = editModel.FirstName;
            dataItem.LastName = editModel.LastName;
            dataItem.Title = editModel.Title;
            dataItem.HireDate = editModel.HireDate;
            // Post changes to the database.
            if (e.IsNew)
                await Northwind.AddAsync(dataItem);
            await Northwind.SaveChangesAsync();
            // Reload the entire Grid.
            GridDataSource = await Northwind.Employees.ToListAsync();
        }
    }

    async Task OnDataItemDeleting(GridDataItemDeletingEventArgs e) {
        // Re-query a data item from the database.
        var dataItem = Northwind.Employees.Find((e.DataItem as Employee).EmployeeId);
        if (dataItem != null) {
            // Remove the data item from the database.
            Northwind.Remove(dataItem);
            await Northwind.SaveChangesAsync();
            // Reload the entire Grid.
            GridDataSource = await Northwind.Employees.ToListAsync();
        }
    }

    public void 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);
    }
}

Startup.cs (.NET 5.0)

using Microsoft.EntityFrameworkCore;
// ...
    public class Startup {
    // ...
        public void ConfigureServices(IServiceCollection services) {
        // ...
            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);
            });
        }
        // ...
    }

Program.cs (.NET 6.0)

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);
});

Implements

ShowRowDeleteConfirmation(Int32)