DxTreeList.ClearSelection() Method

Clears selection.

Namespace: DevExpress.Blazor

Assembly: DevExpress.Blazor.v24.2.dll

NuGet Package: DevExpress.Blazor

Declaration

public void ClearSelection()

Remarks

TreeList rows can be selected in the following ways:

• Users click rows, tap rows, or execute keyboard shortcuts to select rows. To enable this functionality, set the AllowSelectRowByClick property to true.
• Users click checkboxes or radio buttons in the selection column. To display this column, declare a DxTreeListSelectionColumn object in the Columns template.
• You call the Select* method. Refer to the TreeList’s member table for the list of available methods.

Call the ClearSelection method to clear selection of all rows on all pages, including rows hidden by a filter:

Razor

@inject EmployeeTaskService EmployeeTaskService

<style>
    .my-button {
        width: 200px;
    }
</style>

<DxTreeList @ref="MyTreeList"
            Data="TreeListData"
            KeyFieldName="Id"
            ParentKeyFieldName="ParentId"
            AllowSelectRowByClick="true"
            @bind-SelectedDataItems="@SelectedDataItems">
    <Columns>
        <DxTreeListDataColumn FieldName="Name" Caption="Task" />
        <DxTreeListDataColumn FieldName="EmployeeName" />
        <DxTreeListDataColumn FieldName="StartDate" />
        <DxTreeListDataColumn FieldName="DueDate" />
    </Columns>
</DxTreeList>
<br />
<DxButton Click="() => MyTreeList.ClearSelection()" CssClass="my-button" Text="Clear Selection" />

@code {
    List<EmployeeTask> TreeListData { get; set; }
    IReadOnlyList<object> SelectedDataItems { get; set; }
    ITreeList MyTreeList { get; set; }

    protected override void OnInitialized() {
        TreeListData = EmployeeTaskService.GenerateData();
        SelectedDataItems = TreeListData.Skip(1).Take(2).ToList();
    }
}

Product

using System;
using System.Collections.Generic;

#nullable disable

namespace TreeList.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 TreeList.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);
});

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

Implements

ClearSelection()

ClearSelection()