The DevExpress Blazor List Box supports the following selection modes: Single (default), Multiple , or None . Use the SelectionMode property to specify the mode.
Single Selection (Default)
Users can select one List Box item at a time.
Use the Value property to get or set the selected item (you can use two-way data binding ).
Handle the ValueChanged event to respond to selection changes (if you use one-way data binding).
<DxListBox Data="@Staff.DataSource"
@bind-Value="@Value"
TextFieldName="@nameof(Person.Text)"/>
@code{
Person Value;
}
namespace StaffData {
public static class Staff {
private static readonly Lazy<List<Person>> dataSource = new Lazy<List<Person>>(() => {
var dataSource = new List<Person>() {
new Person() { Id = 0 , FirstName = "John", LastName = "Heart", Department=Department.Electronics },
new Person() { Id = 1 , FirstName = "Samantha", LastName = "Bright", Department=Department.Motors },
new Person() { Id = 2 , FirstName = "Arthur", LastName = "Miller", Department=Department.Software },
new Person() { Id = 3 , FirstName = "Robert", LastName = "Reagan", Department=Department.Electronics },
new Person() { Id = 4 , FirstName= "Greta", LastName = "Sims", Department=Department.Motors },
new Person() { Id = 5 , FirstName = "Brett", LastName = "Wade", Department=Department.Software },
new Person() { Id = 6 , FirstName = "Sandra", LastName = "Johnson", Department=Department.Electronics },
new Person() { Id = 7 , FirstName = "Edward", LastName = "Holmes", Department=Department.Motors },
new Person() { Id = 8 , FirstName = "Barbara", LastName = "Banks", Department=Department.Software },
new Person() { Id = 9 , FirstName = "Kevin", LastName = "Carter", Department=Department.Electronics },
new Person() { Id = 10, FirstName = "Cynthia", LastName = "Stanwick", Department=Department.Motors },
new Person() { Id = 11, FirstName = "Sam", LastName = "Hill", Department=Department.Electronics }};
return dataSource;
});
public static List<Person> DataSource { get { return dataSource.Value; } }
}
public class Person {
public int Id { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
public Department Department { get; set; }
public string Text => $"{FirstName} {LastName} ({Department} Dept.)";
public override bool Equals(object obj) {
if (obj is Person typedObj) {
return (this.Id == typedObj.Id) && (this.FirstName == typedObj.FirstName) && (this.LastName == typedObj.LastName)
&& (this.Department == typedObj.Department);
}
return base.Equals(obj);
}
public override int GetHashCode() {
return HashCode.Combine(Id, FirstName, LastName);
}
}
public enum Department { Motors, Electronics, Software }
}
Run Demo: List Box - Overview
VIDEO
Multiple Selection
Users can select multiple items.
The following code enables multiple selection in the List Box, adds checkboxes to items, and shows the Select All checkbox:
@using StaffData
<DxListBox Data="@Staff.DataSource"
TextFieldName="@nameof(Person.Text)"
SelectionMode="ListBoxSelectionMode.Multiple"
ShowCheckboxes="true"
ShowSelectAllCheckbox="true"
@bind-Values="@Values">
</DxListBox>
@code {
IEnumerable<Person> Values { get; set; }
}
namespace StaffData {
public static class Staff {
private static readonly Lazy<List<Person>> dataSource = new Lazy<List<Person>>(() => {
var dataSource = new List<Person>() {
new Person() { Id= 0 , FirstName="John", LastName="Heart", Department=Department.Electronics },
new Person() { Id= 1 , FirstName="Samantha", LastName="Bright", Department=Department.Motors },
new Person() { Id= 2 , FirstName="Arthur", LastName="Miller", Department=Department.Software },
new Person() { Id= 3 , FirstName="Robert", LastName="Reagan", Department=Department.Electronics },
new Person() { Id= 4 , FirstName="Greta", LastName="Sims", Department=Department.Motors },
new Person() { Id= 5 , FirstName="Brett", LastName="Wade", Department=Department.Software },
new Person() { Id= 6 , FirstName="Sandra", LastName="Johnson", Department=Department.Electronics },
new Person() { Id= 7 , FirstName="Edward", LastName="Holmes", Department=Department.Motors },
new Person() { Id= 8 , FirstName="Barbara", LastName="Banks", Department=Department.Software },
new Person() { Id= 9 , FirstName="Kevin", LastName="Carter", Department=Department.Electronics },
new Person() { Id= 10, FirstName="Cynthia", LastName="Stanwick", Department=Department.Motors },
new Person() { Id= 11, FirstName="Sam", LastName="Hill", Department=Department.Electronics }};
return dataSource;
});
public static List<Person> DataSource { get { return dataSource.Value; } }
}
public class Person {
public int Id { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
public Department Department { get; set; }
public string Text => $"{FirstName} {LastName} ({Department} Dept.)";
public override bool Equals(object obj) {
if (obj is Person typedObj) {
return (this.Id == typedObj.Id) && (this.FirstName == typedObj.FirstName) && (this.LastName == typedObj.LastName)
&& (this.Department == typedObj.Department);
}
return base.Equals(obj);
}
}
public enum Department { Motors, Electronics, Software }
}
Run Demo: List Box - Multiple Selection
VIDEO
Disable Selection
Users cannot select items. Use this mode when you want to display a read-only list of items, handle item clicks without selection state, or create a custom selection behavior.
@using BlazorApp.Data
<DxListBox Data="@Staff.DataSource"
@bind-Values="@Values"
TextFieldName="@nameof(Person.Text)"
SelectionMode="ListBoxSelectionMode.None" >
</DxListBox>
@code {
IEnumerable<Person> Values { get; set; } = Staff.DataSource.Take(1);
}
namespace StaffData {
public static class Staff {
private static readonly Lazy<List<Person>> dataSource = new Lazy<List<Person>>(() => {
var dataSource = new List<Person>() {
new Person() { Id = 0 , FirstName = "John", LastName = "Heart", Department=Department.Electronics },
new Person() { Id = 1 , FirstName = "Samantha", LastName = "Bright", Department=Department.Motors },
new Person() { Id = 2 , FirstName = "Arthur", LastName = "Miller", Department=Department.Software },
new Person() { Id = 3 , FirstName = "Robert", LastName = "Reagan", Department=Department.Electronics },
new Person() { Id = 4 , FirstName= "Greta", LastName = "Sims", Department=Department.Motors },
new Person() { Id = 5 , FirstName = "Brett", LastName = "Wade", Department=Department.Software },
new Person() { Id = 6 , FirstName = "Sandra", LastName = "Johnson", Department=Department.Electronics },
new Person() { Id = 7 , FirstName = "Edward", LastName = "Holmes", Department=Department.Motors },
new Person() { Id = 8 , FirstName = "Barbara", LastName = "Banks", Department=Department.Software },
new Person() { Id = 9 , FirstName = "Kevin", LastName = "Carter", Department=Department.Electronics },
new Person() { Id = 10, FirstName = "Cynthia", LastName = "Stanwick", Department=Department.Motors },
new Person() { Id = 11, FirstName = "Sam", LastName = "Hill", Department=Department.Electronics }};
return dataSource;
});
public static List<Person> DataSource { get { return dataSource.Value; } }
}
public class Person {
public int Id { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
public Department Department { get; set; }
public string Text => $"{FirstName} {LastName} ({Department} Dept.)";
public override bool Equals(object obj) {
if (obj is Person typedObj) {
return (this.Id == typedObj.Id) && (this.FirstName == typedObj.FirstName) && (this.LastName == typedObj.LastName)
&& (this.Department == typedObj.Department);
}
return base.Equals(obj);
}
public override int GetHashCode() {
return HashCode.Combine(Id, FirstName, LastName);
}
}
public enum Department { Motors, Electronics, Software }
}
Select Items in the UI
Users can select List Box items in the following ways:
Mouse/Touch
In single selection mode, click or tap an item.
In multiple selection mode:
Hold Ctrl and click items to select them individually.
Hold Shift to select a range of items.
Click checkboxes next to items (when ShowCheckboxes is true).
Click the Select All checkbox (when both ShowSelectAllCheckbox and ShowCheckboxes are true).
Keyboard
Use ↑ and ↓ arrows to focus an item.
Press Space to select/deselect the focused item.
Press Enter to trigger an item click (requires an ItemClick event handler).
Refer to List Box - Keyboard Support for more information.