Class ListBoxEvents<TValue, TItem>

Declares the set of event callbacks exposed by SfListBox<TValue, TItem> for handling filtering, selection, drag-and-drop, creation, and more.

Inheritance
object
ComponentBase
OwningComponentBase
SfOwningComponentBase
ListBoxEvents<TValue, TItem>
Implements
Inherited Members
Namespace: Syncfusion.Blazor.DropDowns
Assembly: Syncfusion.Blazor.dll
Syntax
public class ListBoxEvents<TValue, TItem> : SfOwningComponentBase, IComponent, IHandleEvent, IHandleAfterRender, IDisposable
Type Parameters
Name Description
TValue

The type used to represent selected item values (e.g., string[] or int).
TItem

The data type for items displayed in the ListBox (e.g., an entity or simple value).
Remarks

Use these events to customize data requests, selection logic, UI feedback, and integration scenarios for SfListBox<TValue, TItem>.

Examples

This example demonstrates how to listen for creation, value changes, and filtering events in a ListBox:

<SfListBox @ref="ListBoxObj" DataSource="@vehicleData" TValue="string[]" TItem="ListItem">
    <ListBoxFieldSettings Text="Text" Value="ID"></ListBoxFieldSettings>
    <ListBoxEvents TValue="string[]" Created="OnCreated" ValueChange="OnValueChange" Filtering="OnFiltering"></ListBoxEvents>
</SfListBox>
@code {
    SfListBox<string[], ListItem> ListBoxObj;
    public List<ListItem> vehicleData = new List<ListItem> {
        new ListItem { Text = "Hennessey Venom", ID = "List-01" },
        new ListItem { Text = "Bugatti Chiron", ID = "List-02" },
        new ListItem { Text = "Bugatti Veyron Super Sport", ID = "List-03" }
    };
    private Task OnCreated(object args) => ListBoxObj.SelectItemsAsync(Value, true);
    private void OnValueChange(ListBoxChangeEventArgs<string[], ListItem> args) { /* React to selection changes */ }
    private void OnFiltering(FilteringEventArgs args) { /* Custom filtering logic */ }
    public class ListItem { public string Text {get;set;} public string ID {get;set;} }
}

Constructors

ListBoxEvents()

Declaration
public ListBoxEvents()

Properties

Created

Raised when the ListBox is fully initialized and ready for interaction.

Declaration
[Parameter]
public EventCallback<object> Created { get; set; }
Property Value
Type
EventCallback<object>
Examples
private Task OnCreated(object args) { /* Additional setup after creation */ }

Destroyed

Raised when the ListBox is destroyed, letting you clean up state or subscriptions.

Declaration
[Parameter]
public EventCallback<object> Destroyed { get; set; }
Property Value
Type
EventCallback<object>

DragStart

Triggered before starting to drag an item, enabling custom logic or cancellation.

Declaration
[Parameter]
public EventCallback<DragEventArgs<TItem>> DragStart { get; set; }
Property Value
Type
EventCallback<DragEventArgs<TItem>>
Remarks

Available only when AllowDragAndDrop is true.

Dropped

Triggered after successful drop operation to let you respond to or process item movement.

Declaration
[Parameter]
public EventCallback<DropEventArgs<TItem>> Dropped { get; set; }
Property Value
Type
EventCallback<DropEventArgs<TItem>>
Remarks

Available only when AllowDragAndDrop is true.

Filtering

Raised whenever the user enters text to filter or search ListBox items.

Declaration
[Parameter]
public EventCallback<FilteringEventArgs> Filtering { get; set; }
Property Value
Type
EventCallback<FilteringEventArgs>
Remarks

Available only when AllowFiltering is true.

Examples
private void OnFiltering(FilteringEventArgs args) {
    // Customize query for dynamic filtering
}

ListBoxItemKeyDown

Triggered when performing a keydown action in a ListBox item (e.g. for advanced keyboard handling).

Declaration
[Parameter]
public EventCallback<ListBoxKeyDownEventArgs> ListBoxItemKeyDown { get; set; }
Property Value
Type
EventCallback<ListBoxKeyDownEventArgs>

OnActionBegin

Invoked before fetching data from a remote server in the SfListBox<TValue, TItem>. Allows you to customize request parameters or cancel the request.

Declaration
[Parameter]
public EventCallback<ActionBeginEventArgs> OnActionBegin { get; set; }
Property Value
Type
EventCallback<ActionBeginEventArgs>

OnActionComplete

Invoked after data has been successfully fetched from a remote server.

Declaration
[Parameter]
public EventCallback<ActionCompleteEventArgs<TItem>> OnActionComplete { get; set; }
Property Value
Type
EventCallback<ActionCompleteEventArgs<TItem>>

OnActionFailure

Triggered when a data fetch from the server fails. Use to log or display errors.

Declaration
[Parameter]
public EventCallback<object> OnActionFailure { get; set; }
Property Value
Type
EventCallback<object>

OnDrop

Triggered before dropping items onto the ListBox, allowing cancellation or custom drop behavior.

Declaration
[Parameter]
public EventCallback<DropEventArgs<TItem>> OnDrop { get; set; }
Property Value
Type
EventCallback<DropEventArgs<TItem>>
Remarks

Available only when AllowDragAndDrop is true.

OnItemRender

Occurs before rendering each item in the ListBox, giving you the chance to customize item content or appearance.

Declaration
[Parameter]
public EventCallback<BeforeItemRenderEventArgs<TItem>> OnItemRender { get; set; }
Property Value
Type
EventCallback<BeforeItemRenderEventArgs<TItem>>

ValueChange

Triggered when the selected value(s) of the ListBox change.

Declaration
[Parameter]
public EventCallback<ListBoxChangeEventArgs<TValue, TItem>> ValueChange { get; set; }
Property Value
Type
EventCallback<ListBoxChangeEventArgs<TValue, TItem>>

Methods

Dispose(bool)

Declaration
protected override void Dispose(bool disposing)
Parameters
Type Name Description
bool disposing
Overrides

OnInitializedAsync()

Declaration
protected override Task OnInitializedAsync()
Returns
Type
Task
Overrides

Implements