Class DropDownListEvents<TValue, TItem>

Defines the SfDropDownList events of the component.

Inheritance

System.Object

DropDownListEvents<TValue, TItem>

Namespace: Syncfusion.Blazor.DropDowns

Assembly: Syncfusion.Blazor.dll

Syntax

public class DropDownListEvents<TValue, TItem> : OwningComponentBase

Type Parameters

Name	Description
TValue	A type which provides for the Value poperty type.
TItem	A type which provides data list schema for the dropdown list events.

Constructors

DropDownListEvents()

Declaration

public DropDownListEvents()

Properties

BaseParent

Specifies the base parent of the component.

Declaration

protected SfDropDownList<TValue, TItem> BaseParent { get; set; }

Property Value

Type
SfDropDownList<TValue, TItem>

Blur

Gets or sets the event callback that will be invoked when the dropdown list loses focus.

Declaration

public EventCallback<object> Blur { get; set; }

Property Value

Type
Microsoft.AspNetCore.Components.EventCallback<System.Object>

Closed

Gets or sets the event callback that will be invoked after the dropdown popup has been closed.

Declaration

public EventCallback<ClosedEventArgs> Closed { get; set; }

Property Value

Type
Microsoft.AspNetCore.Components.EventCallback<ClosedEventArgs>

Created

Gets or sets the event callback that will be invoked when the component is created.

Declaration

public EventCallback<object> Created { get; set; }

Property Value

Type
Microsoft.AspNetCore.Components.EventCallback<System.Object>

DataBound

Gets or sets the event callback that will be invoked when data source is populated in the popup list.

Declaration

public EventCallback<DataBoundEventArgs> DataBound { get; set; }

Property Value

Type
Microsoft.AspNetCore.Components.EventCallback<DataBoundEventArgs>

Destroyed

Gets or sets the event callback that will be invoked when the component is destroyed.

Declaration

public EventCallback<object> Destroyed { get; set; }

Property Value

Type
Microsoft.AspNetCore.Components.EventCallback<System.Object>

Filtering

Gets or sets the event callback that will be invoked on typing a character in the filter textbox.

Declaration

public EventCallback<FilteringEventArgs> Filtering { get; set; }

Property Value

Type
Microsoft.AspNetCore.Components.EventCallback<FilteringEventArgs>

Remarks

You can prevent the default filter action and make your query enable the PreventDefaultAction event argument, and pass the modify data source and query in FilterAsync(IEnumerable<TItem>, Query, FieldSettingsModel) method.

Examples

<SfDropDownList @ref="DDLObj" TItem="string" TValue="string" AllowFiltering="true" DataSource="@MyList">
    <DropDownListEvents TValue="string" TItem="string" Filtering="@OnFilteringHandler" />
</SfDropDownList>
@code{
    SfDropDownList<string, string> DDLObj { get; set; }
    protected List<string> MyList = new List<string>() { "Small", "Medium", "Large" };
    public async Task OnFilteringHandler(FilteringEventArgs args) {
        args.PreventDefaultAction = true;
        var query = new Query().Where(new WhereFilter() { Field = "Text", Operator = "contains", value = args.Text, IgnoreCase = true });
        await DDLObj.FilterAsync(MyList, query);
    }
  }

Focus

Gets or sets the event callback that will be invoked when the component is the focus.

Declaration

public EventCallback<object> Focus { get; set; }

Property Value

Type
Microsoft.AspNetCore.Components.EventCallback<System.Object>

OnActionBegin

Gets or sets the event callback that will be invoked before fetching data from the data source.

Declaration

public EventCallback<ActionBeginEventArgs> OnActionBegin { get; set; }

Property Value

Type
Microsoft.AspNetCore.Components.EventCallback<ActionBeginEventArgs>

OnActionComplete

Gets or sets the evnet callback that will be invoked after data is fetched successfully from the data source.

Declaration

public EventCallback<ActionCompleteEventArgs<TItem>> OnActionComplete { get; set; }

Property Value

Type
Microsoft.AspNetCore.Components.EventCallback<ActionCompleteEventArgs<TItem>>

OnActionFailure

Gets or sets the event callback that will be invoked when the data fetch request fails.

Declaration

public EventCallback<Exception> OnActionFailure { get; set; }

Property Value

Type
Microsoft.AspNetCore.Components.EventCallback<System.Exception>

OnClose

Gets or sets the event callback that will be invoked before the dropdown popup is close.

Declaration

public EventCallback<PopupEventArgs> OnClose { get; set; }

Property Value

Type
Microsoft.AspNetCore.Components.EventCallback<PopupEventArgs>

Remarks

You can prevent the dropdown popup close action using Cancel and the popup remains opened always.

Examples

<SfDropDownList TItem="string" TValue="string" DataSource="@MyList">
    <DropDownListEvents TValue="string" TItem="string" OnClose="@OnCloseHandler"/>
</SfDropDownList>
@code{
    protected List<string> MyList = new List<string>() { "Small", "Medium", "Large" };
    public void OnCloseHandler(PopupEventArgs args) {
        args.Cancel = true;
    }
  }

OnOpen

Gets or sets the event callback that will be invoked when the dropdown popup before opens.

Declaration

public EventCallback<BeforeOpenEventArgs> OnOpen { get; set; }

Property Value

Type
Microsoft.AspNetCore.Components.EventCallback<BeforeOpenEventArgs>

Remarks

You can prevent the dropdown popup open action using Cancel.

Examples

<SfDropDownList TItem="string" TValue="string" DataSource="@MyList">
    <DropDownListEvents TValue="string" TItem="string" OnOpen="@OnOpenHandler"/>
</SfDropDownList>
@code{
    protected List<string> MyList = new List<string>() { "Small", "Medium", "Large" };
    public void OnOpenHandler(BeforeOpenEventArgs args) {
        args.Cancel = true;
    }
  }

OnValueSelect

Gets or sets the event callback that will be when an item is selected from the dropdown popup by the user either with mouse/tap or with keyboard navigation.

Declaration

public EventCallback<SelectEventArgs<TItem>> OnValueSelect { get; set; }

Property Value

Type
Microsoft.AspNetCore.Components.EventCallback<SelectEventArgs<TItem>>

Remarks

You can prevent the item selection action using Cancel.

Examples

<SfDropDownList TItem="string" TValue="string" DataSource="@MyList">
    <DropDownListEvents TValue="string" TItem="string" OnValueSelect="@OnSelectHandler" />
</SfDropDownList>
@code{
    protected List<string> MyList = new List<string>() { "Small", "Medium", "Large" };
    public void OnSelectHandler(SelectEventArgs<string> args) {
        if(args.ItemData== "Medium")
            args.Cancel = true;
    }
  }

Opened

Gets or sets the event callback that will be invoked when the dropdown popup opens.

Declaration

public EventCallback<PopupEventArgs> Opened { get; set; }

Property Value

Type
Microsoft.AspNetCore.Components.EventCallback<PopupEventArgs>

ValueChange

Gets or sets the event callback that will be invoked when the Value property changed.

Declaration

public EventCallback<ChangeEventArgs<TValue, TItem>> ValueChange { get; set; }

Property Value

Type
Microsoft.AspNetCore.Components.EventCallback<ChangeEventArgs<TValue, TItem>>

Remarks

This event triggers when an item in a popup is selected or when the model value is changed by user.

Examples

<SfDropDownList TItem="string" TValue="string" DataSource="@MyList">
    <DropDownListEvents TValue="string" TItem="string" ValueChange="@OnChange"/>
</SfDropDownList>
@code{
    protected List<string> MyList = new List<string>() { "Small", "Medium", "Large" };
    public void OnChange(Syncfusion.Blazor.DropDowns.ChangeEventArgs<string, string> args) {
        var DDLValue = args.Value;
    }
  }

Methods

ComponentDispose(Boolean)

Declaration

protected void ComponentDispose(bool disposing)

Parameters

Type	Name	Description
System.Boolean	disposing