Class ComboBoxEvents<TValue, TItem>

Represents the event handlers for a ComboBox component in the Blazor framework.

Inheritance

System.Object

ComboBoxEvents<TValue, TItem>

Namespace: Syncfusion.Blazor.DropDowns

Assembly: Syncfusion.Blazor.dll

Syntax

public class ComboBoxEvents<TValue, TItem> : OwningComponentBase

Type Parameters

Name	Description
TValue	The type of value associated with the ComboBox.
TItem	The type of item associated with the ComboBox.

Constructors

ComboBoxEvents()

Declaration

public ComboBoxEvents()

Properties

Blur

Gets or sets the event callback that will be invoked when the ComboBox component 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>

CustomValueSpecifier

Gets or sets the event callback that will be invoked when custom values (not present in the data source) are selected in the ComboBox component.

Declaration

public EventCallback<CustomValueSpecifierEventArgs<TItem>> CustomValueSpecifier { get; set; }

Property Value

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

Examples

<SfComboBox TValue="int" TItem="Countries" DataSource="@CountryList">
   <ComboBoxEvents TValue="int" TItem="Countries" CustomValueSpecifier="@customValue"></ComboBoxEvents>
   <ComboBoxFieldSettings Text="Name" Value="Code"></ComboBoxFieldSettings>
</SfComboBox>
@code{
    public class Countries {
        public string Name { get; set; }
        public int Code { get; set; }
    }
    private List<Countries> CountryList = new List<Countries>() {
        new Countries(){ Code= 101, Name= "Australia" },
        new Countries(){ Code= 102, Name= "Canada" }
     }
    private void customValue(CustomValueSpecifierEventArgs<Countries> args) {
        args.Item = new Countries() { Code = 103, Name = args.Text };
    }
  }

DataBound

Gets or sets the event callback that will be invoked when the 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 ComboBox.

Declaration

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

Property Value

Type
Microsoft.AspNetCore.Components.EventCallback<FilteringEventArgs>

Remarks

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

Examples

<SfComboBox @ref="ComboBoxObj" TItem="string" TValue="string" AllowFiltering="true" DataSource="@MyList">
    <ComboBoxEvents TValue="string" TItem="string" Filtering="@OnFilteringHandler" />
</SfComboBox>
@code{
    SfComboBox<string, string> ComboBoxObj { 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 ComboBoxObj.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 event callback that will be invoked after data is fetched suction 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 closed.

Declaration

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

Property Value

Type
Microsoft.AspNetCore.Components.EventCallback<PopupEventArgs>

Remarks

Prevent the dropdown popup close action using Cancel and the popup remains opened always.

Examples

<SfComboBox TItem="string" TValue="string" DataSource="@MyList">
    <ComboBoxEvents TValue="string" TItem="string" OnClose="@OnCloseHandler"/>
</SfComboBox>
@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 it opens.

Declaration

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

Property Value

Type
Microsoft.AspNetCore.Components.EventCallback<BeforeOpenEventArgs>

Remarks

Prevent the dropdown popup open action using Cancel.

Examples

<SfComboBox TItem="string" TValue="string" DataSource="@MyList">
    <ComboBoxEvents TValue="string" TItem="string" OnOpen="@OnOpenHandler"/>
</SfComboBox>
@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 invoked when an item is selected from the dropdown popup by the user either with a mouse tap or with a keyboard navigation.

Declaration

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

Property Value

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

Remarks

Prevent the item selection action using Cancel.

Examples

<SfComboBox TItem="string" TValue="string" DataSource="@MyList">
    <ComboBoxEvents TValue="string" TItem="string" OnValueSelect="@OnSelectHandler" />
</SfComboBox>
@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 user changes the model value.

Examples

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

Methods

ComponentDispose(Boolean)

Declaration

protected void ComponentDispose(bool disposing)

Parameters

Type	Name	Description
System.Boolean	disposing