DxGrid.SelectRows(IEnumerable<Int32>, Boolean) Method

Selects or deselects rows with the specified visible indexes.

Namespace: DevExpress.Blazor

Assembly: DevExpress.Blazor.v23.1.dll

NuGet Package: DevExpress.Blazor

Declaration

public void SelectRows(
    IEnumerable<int> visibleIndexes,
    bool selected = true
)

Parameters

Name	Type	Description
visibleIndexes	IEnumerable<Int32>	Specifies a collection of visible indexes.

Optional Parameters

Name	Type	Default	Description
selected	Boolean	True	true to select rows; false to deselect rows.

Remarks

The following methods allow you to manage Grid selection:

• SelectRow (DeselectRow)
• SelectRows (DeselectRows)
• SelectDataItem (DeselectDataItem)
• SelectDataItems (DeselectDataItems)
• SelectAllOnPage (DeselectAllOnPage)
• SelectAllAsync (DeselectAllAsync)
• ClearSelection

When the SelectionMode property is set to GridSelectionMode.Multiple, the SelectRows method allows you to add multiple rows to current selection. Call this method and pass a collection of visible indexes as the parameter.

If you call the SelectRows method in GridSelectionMode.Single mode, it clears selection and selects only one row with the last specified index.

Note

When the Grid calculates visible indexes, it counts data rows and group rows. However, only data rows can be selected.

To deselect rows by their visible indexes, do any of the following:

• Call the DeselectRows method.
• Call the SelectRows method and pass false as the second parameter.

To access data items that correspond to selected rows, implement two-way binding for the SelectedDataItems property or handle the SelectedDataItemsChanged event.

The following example selects and deselects rows whose indexes are between 3 and 5:

Razor

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

<DxGrid Data="GridDataSource"
        AllowSelectRowByClick="true"
        @bind-SelectedDataItems="@SelectedDataItems"
        KeyFieldName="ProductId"
        @ref="MyGrid">
    <Columns>
        <DxGridDataColumn FieldName="ProductName" />
        <DxGridDataColumn FieldName="UnitPrice" />
        <DxGridDataColumn FieldName="QuantityPerUnit" />
        <DxGridDataColumn FieldName="UnitsInStock" />
    </Columns>
</DxGrid>
<br />

<DxButton Click="() => MyGrid.SelectRows(RowIndexes)">Select Rows 4-6</DxButton>
<DxButton Click="() => MyGrid.DeselectRows(RowIndexes)">Deselect Rows 4-6</DxButton>

@code {
    IEnumerable<object> GridDataSource { get; set; }
    NorthwindContext Northwind { get; set; }
    IReadOnlyList<object> SelectedDataItems { get; set; }
    IGrid MyGrid { get; set; }
    int[] RowIndexes { get; set; } = new int[] { 3, 4, 5 };

    protected override void OnInitialized() {
        Northwind = NorthwindContextFactory.CreateDbContext();
        GridDataSource = Northwind.Products
            .ToList();
        SelectedDataItems = GridDataSource.Skip(1).Take(2).ToList();
    }

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

Product

using System;
using System.Collections.Generic;

#nullable disable

namespace Grid.Northwind {
    public partial class Product {
        public Product() {
            OrderDetails = new HashSet<OrderDetail>();
        }

        public int ProductId { get; set; }
        public string ProductName { get; set; }
        public int? SupplierId { get; set; }
        public int? CategoryId { get; set; }
        public string QuantityPerUnit { get; set; }
        public decimal? UnitPrice { get; set; }
        public short? UnitsInStock { get; set; }
        public short? UnitsOnOrder { get; set; }
        public short? ReorderLevel { get; set; }
        public bool Discontinued { get; set; }

        public virtual Category Category { get; set; }
        public virtual Supplier Supplier { get; set; }
        public virtual ICollection<OrderDetail> OrderDetails { 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<Product> Products { 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.Entity<Product>(entity => {
                entity.HasIndex(e => e.CategoryId, "CategoriesProducts");
                entity.HasIndex(e => e.CategoryId, "CategoryID");
                entity.HasIndex(e => e.ProductName, "ProductName");
                entity.HasIndex(e => e.SupplierId, "SupplierID");
                entity.HasIndex(e => e.SupplierId, "SuppliersProducts");
                entity.Property(e => e.ProductId).HasColumnName("ProductID");
                entity.Property(e => e.CategoryId).HasColumnName("CategoryID");
                entity.Property(e => e.ProductName)
                    .IsRequired()
                    .HasMaxLength(40);
                entity.Property(e => e.QuantityPerUnit).HasMaxLength(20);
                entity.Property(e => e.ReorderLevel).HasDefaultValueSql("((0))");
                entity.Property(e => e.SupplierId).HasColumnName("SupplierID");
                entity.Property(e => e.UnitPrice)
                    .HasColumnType("money")
                    .HasDefaultValueSql("((0))");
                entity.Property(e => e.UnitsInStock).HasDefaultValueSql("((0))");
                entity.Property(e => e.UnitsOnOrder).HasDefaultValueSql("((0))");
                entity.HasOne(d => d.Category)
                    .WithMany(p => p.Products)
                    .HasForeignKey(d => d.CategoryId)
                    .HasConstraintName("FK_Products_Categories");
                entity.HasOne(d => d.Supplier)
                    .WithMany(p => p.Products)
                    .HasForeignKey(d => d.SupplierId)
                    .HasConstraintName("FK_Products_Suppliers");
            });
            // ...
            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: Data Grid - Selection API

Note

When you use a GridDevExtremeDataSource, do not call the SelectRows method for rows that are outside the visible display range. The GridDevExtremeDataSource loads only a small number of rows based on the page size (in the paging navigation mode) or the viewport size (in the virtual scrolling mode). If you have references to the corresponding data items, you can call the SelectDataItems(IEnumerable<Object>, Boolean) method.

For more information about selection in the Grid component, refer to the following topic: Selection and Focus in Blazor Grid.

Implements

SelectRows(IEnumerable<Int32>, Boolean)