Syncfusion.Blazor.DropDowns.SfDropDownBase<TItem>.HighlightSearch(System.String, System.String, System.Boolean, Syncfusion.Blazor.DropDowns.FilterType)

Syncfusion.Blazor.DropDowns.SfDropDownBase<TItem>.IncrementalSearch(System.String, System.Collections.Generic.IEnumerable<TItem>, System.Nullable<System.Int32>, System.Boolean)

Syncfusion.Blazor.DropDowns.SfDropDownBase<TItem>.IsActionFailed

Syncfusion.Blazor.DropDowns.SfDropDownBase<TItem>.IsMinimalData

Syncfusion.Blazor.DropDowns.SfDropDownBase<TItem>.ItemData

Syncfusion.Blazor.DropDowns.SfDropDownBase<TItem>.ListDataSource

Syncfusion.Blazor.DropDowns.SfDropDownBase<TItem>.MainData

Syncfusion.Blazor.DropDowns.SfDropDownBase<TItem>.OnInitializedAsync()

Syncfusion.Blazor.DropDowns.SfDropDownBase<TItem>.OnParametersSetAsync()

Syncfusion.Blazor.DropDowns.SfDropDownBase<TItem>.RefreshVirtualIndices()

Syncfusion.Blazor.DropDowns.SfDropDownBase<TItem>.RenderItemsAsync(System.Collections.Generic.IEnumerable<TItem>)

Syncfusion.Blazor.DropDowns.SfDropDownBase<TItem>.RenderListItemsAsync(System.Collections.Generic.IEnumerable<TItem>, Syncfusion.Blazor.DropDowns.FieldSettingsModel, Syncfusion.Blazor.Data.Query)

Syncfusion.Blazor.DropDowns.SfDropDownBase<TItem>.Search(System.String, System.Collections.Generic.IEnumerable<TItem>, System.String, System.Boolean)

Syncfusion.Blazor.DropDowns.SfDropDownBase<TItem>.SetListDataAsync(System.Collections.Generic.IEnumerable<TItem>, Syncfusion.Blazor.DropDowns.FieldSettingsModel, Syncfusion.Blazor.Data.Query)

Syncfusion.Blazor.DropDowns.SfDropDownBase<TItem>.TotalCount

Syncfusion.Blazor.DropDowns.SfDropDownBase<TItem>.UpdateListHeight(System.Double)

Syncfusion.Blazor.DropDowns.SfDropDownBase<TItem>.VirtualAction

Namespace: Syncfusion.Blazor.DropDowns

Assembly: Syncfusion.Blazor.dll

Syntax

public class SfDropDownList<TValue, TItem> : SfDropDownBase<TItem>, IInputBase, IDropDowns, IVirtualList<TItem>

Type Parameters

Name	Description
TValue	Specifies the value type.
TItem	Specifies the type of SfDropDownList.

Examples

In the following code example, a basic DropDownList component is initialized with simple list items.

<SfDropDownList TItem="string" TValue="string" DataSource="@MyList">
</SfDropDownList>
@code{
    protected List<string> MyList = new List<string>() { "Small", "Medium", "Large" };
}

Constructors

SfDropDownList()

Declaration

public SfDropDownList()

Fields

ASSERTIVE

specifies the assertive string.

Declaration

protected const string ASSERTIVE = "assertive"

Field Value

Type
System.String

BOTH

Declaration

protected const string BOTH = "both"

Field Value

Type
System.String

FALSE

Specifies the string false.

Declaration

protected const string FALSE = "false"

Field Value

Type
System.String

NO_DATA

Specifies the root class of base component.

Declaration

protected const string NO_DATA = "e-content e-dropdownbase e-nodata"

Field Value

Type
System.String

TRUE

Specifies the string true.

Declaration

protected const string TRUE = "true"

Field Value

Type
System.String

Properties

AllowFiltering

Gets or sets a value that indicates whether the filtering option is enabled or not.

Declaration

public bool AllowFiltering { get; set; }

Property Value

Type	Description
System.Boolean	`true`, if the filtering option is enabled and show the filter bar (search box) in the pop-up; otherwise, false.The default value is `false`.

Remarks

The filter action retrieves the matched items using the Filtering event based on the characters typed in the search textbox.

CssClass

Gets or sets a CSS class string to customize the appearance of the SfDropDownList<TValue, TItem> component.

Declaration

public string CssClass { get; set; }

Property Value

Type	Description
System.String	Accepts a CSS class string separated by space to customize the appearance. The default value is `String.Empty`.

Enabled

Gets or sets a value that indicates whether to enable or disable the DropDownListEvents<TValue, TItem> component.

Declaration

public bool Enabled { get; set; }

Property Value

Type	Description
System.Boolean	`true`, if the Dropdown list component is enabled; otherwise, it is disabled. The default value is `false`.

EnablePersistence

Gets or sets whether to persist component's state between page reloads. When set to true, the Value property is persisted.

Declaration

public bool EnablePersistence { get; set; }

Property Value

Type	Description
System.Boolean	`true`, if the component's state persistence is enabled. The default value is `false`.

Remarks

Component's Value property will be stored in browser local storage to persist component's state when page reloads.

EnableRtl

Gets or sets whether the right-to-left direction is enabled or not for the drop-down list component.

Declaration

public bool EnableRtl { get; set; }

Property Value

Type	Description
System.Boolean	`true`, if the right to left direction is enabled for dropdown list component. The default value is `false`.

EnableVirtualization

Gets or sets a value indicating whether the virtual scrolling is enabled or not.

Declaration

public bool EnableVirtualization { get; set; }

Property Value

Type	Description
System.Boolean	`true` if the virtual scrolling for dropdown list; otherwise, `false`. The default is `false`.

Remarks

To improve performance, the EnableVirtualization property is set to true.

FilterBarPlaceholder

Gets or sets the text that is displayed when the filter textbox has no text and removes the focus.

Declaration

public string FilterBarPlaceholder { get; set; }

Property Value

Type	Description
System.String	The text that is displayed when the filter text box has no text. The default value is `String.Empty`.

Remarks

This property value is updated only when the AllowFiltering is enabled.

FloatLabelType

Gets or sets the floating label behavior of the dropdown list. The Placeholder text act as a lable.

Declaration

public FloatLabelType FloatLabelType { get; set; }

Property Value

Type	Description
FloatLabelType	One of the FloatLabelType enumeration. The default value is Never

Remarks

If the FloatLabelType is Never, the placeholder text does not float as a label. If the FloatLabelType is Auto, the placeholder text will float above the DropDownList component as a label after focusing it. If the FloatLabelType is Always, the placeholder text is displayed as a label above the DropDownList component.

Examples

In the following code example, set the float lable as Auto.

<SfDropDownList TItem="string" TValue="string" DataSource="@MyList" Placeholder="Select a value" FloatLabelType="FloatLabelType.Auto">
</SfDropDownList>
@code{
    protected List<string> MyList = new List<string>() { "Small", "Medium", "Large" };
}

FooterTemplate

Gets or sets the customised design content and assigns it to the footer container of the pop-up list.

Declaration

public RenderFragment FooterTemplate { get; set; }

Property Value

Type	Description
Microsoft.AspNetCore.Components.RenderFragment	The template content. The default value in `null`.

Examples

<SfDropDownList TItem="string" TValue="string" DataSource="@MyList">
    <DropDownListTemplates TItem="string">
        <FooterTemplate>
            <span class='footer'>Total list items: 3 </span>
        </FooterTemplate>
    </DropDownListTemplates>
</SfDropDownList>
@code{
    protected List<string> MyList = new List<string>() { "Small", "Medium", "Large" };
}

HeaderTemplate

Gets or sets the customised design content and assigns it to the header container of the popup list.

Declaration

public RenderFragment HeaderTemplate { get; set; }

Property Value

Type	Description
Microsoft.AspNetCore.Components.RenderFragment	The template content. The default value in `null`.

Examples

<SfDropDownList TItem="string" TValue="string" DataSource="@MyList">
    <DropDownListTemplates TItem="string">
        <HeaderTemplate>
            <span class='header'> T-shirt size </span>
        </HeaderTemplate>
    </DropDownListTemplates>
</SfDropDownList>
@code{
    protected List<string> MyList = new List<string>() { "Small", "Medium", "Large" };
}

HtmlAttributes

Gets or sets a collection of additional attributes such as styles, class, and more that will be applied to the dropdown list element.

Declaration

public Dictionary<string, object> HtmlAttributes { get; set; }

Property Value

Type	Description
System.Collections.Generic.Dictionary<System.String, System.Object>	The value as dictionary collection.The default value is `null`

Remarks

Additional attributes can be added by specifying as inline attributes or by specifying @attributes directive.

Examples

<SfDropDownList TItem="string" TValue="string" DataSource="@MyList" HtmlAttributes="@CustomAttribute">
</SfDropDownList>
@code{
    protected List<string> MyList = new List<string>() { "Small", "Medium", "Large" };
    Dictionary<string, object> CustomAttribute = new Dictionary<string, object>()
    {
        { "title", "Select T-shirt size" }
    }
}

ID

Gets or sets the unique identifier for DropDownListEvents<TValue, TItem> component.

Declaration

public string ID { get; set; }

Property Value

Type	Description
System.String	Accepts a string value. The default value is `String.Empty`.

Remarks

You can specify only unique value.

IncrementalListData

Declaration

protected IEnumerable<TItem> IncrementalListData { get; set; }

Property Value

Type
System.Collections.Generic.IEnumerable<TItem>

Index

Gets or sets the index of the selected item in the dropdown list component.

Declaration

public Nullable<int> Index { get; set; }

Property Value

Type	Description
System.Nullable<System.Int32>	The index of the selected items in the list. The default value is `null` which indicates that nothing is selected.

Remarks

Use this property to determine the index of the currently selected item in the list if the dropdown list component allows only one selection.

Exceptions

Type	Condition
System.ArgumentOutOfRangeException	The index was set to less than -1, or greater than or equal to the number of items on the list at the time the list is rendered.

IndexChanged

Gets or sets the callback to trigger when the index changes.

Declaration

public EventCallback<Nullable<int>> IndexChanged { get; set; }

Property Value

Type	Description
Microsoft.AspNetCore.Components.EventCallback<System.Nullable<System.Int32>>	An event callback function.

InputAttributes

Gets or sets a collection of additional attributes such as disabled, value, and more that will be applied to the dropdown list input element.

Declaration

public Dictionary<string, object> InputAttributes { get; set; }

Property Value

Type	Description
System.Collections.Generic.Dictionary<System.String, System.Object>	The value as dictionary collection. The default value is `null`

Remarks

If you configured both the property and equivalent input attribute, then the component considers the property value.

IsAutoComplete

Declaration

protected bool IsAutoComplete { get; set; }

Property Value

Type
System.Boolean

IsComboBox

Declaration

protected bool IsComboBox { get; set; }

Property Value

Type
System.Boolean

IsDropDownList

Declaration

protected bool IsDropDownList { get; set; }

Property Value

Type
System.Boolean

IsIncrementalRequest

Declaration

protected bool IsIncrementalRequest { get; set; }

Property Value

Type
System.Boolean

IsPopupShown

Declaration

protected bool IsPopupShown { get; set; }

Property Value

Type
System.Boolean

IsTabKeyAction

Declaration

protected bool IsTabKeyAction { get; set; }

Property Value

Type
System.Boolean

Placeholder

Gets or sets the text that is displayed when the dropdown list has no value and remove on the focus.

Declaration

public string Placeholder { get; set; }

Property Value

Type	Description
System.String	The text that is displayed when the dropdown list has no value. The default value is `String.Empty`.

Remarks

The property depends on the FloatLabelType property, The placeholder text acts as a label.

PopupDisplayMode

Gets or sets the display mode of the dropdown popup on mobile devices.

Declaration

public PopupDisplayMode PopupDisplayMode { get; set; }

Property Value

Type	Description
PopupDisplayMode	The default value is FullScreen.

Remarks

The PopupDisplayMode enum has two possible values:

FullScreen: The popup opens in fullscreen mode on mobile devices when filtering is enabled. This is applicable for both SfDropDownList<TValue, TItem> and SfMultiSelect<TValue, TItem> components in checkbox mode with filtering enabled.
Inline: The popup opens similarly on both mobile and desktop devices, above the input field without fullscreen mode.

Examples

The following example demonstrates how to use the PopupDisplayMode property:

DropdownList with PopupDisplayMode set to Inline
<SfDropdownList TValue="string" DataSource="@Data" PopupDisplayMode="PopupDisplayMode.Inline">
    <DropDownListFieldSettings Text="Text" Value="Id"></DropDownListFieldSettings>
</SfDropdownList>

@code {
    public List<DropDownData> Data { get; set; } = new List<DropDownData>
    {
        new DropDownData { Id = "1", Text = "Option 1" },
        new DropDownData { Id = "2", Text = "Option 2" },
        new DropDownData { Id = "3", Text = "Option 3" }
    };

    public class DropDownData
    {
        public string Id { get; set; }
        public string Text { get; set; }
    }
}

PopupHeight

Gets or sets the height of the popup list.

Declaration

public string PopupHeight { get; set; }

Property Value

Type	Description
System.String	The preferred height of the popup list in pixels or percentage of the dropdown list. The default value is `300px`.

Remarks

This property accepts pixels or percentage value.

PopupWidth

Gets or sets the width of the popup list. By default, the popup width sets based on the width of the SfDropDownList<TValue, TItem> component.

Declaration

public string PopupWidth { get; set; }

Property Value

Type	Description
System.String	The preferred width of the popup list in pixels or percentage of the dropdown list. The default value is `100%`.

Remarks

This property accepts pixels or percentage value.

Readonly

Gets or sets a value indicating whether the SfDropDownList<TValue, TItem> is in read-only mode or not.

Declaration

public bool Readonly { get; set; }

Property Value

Type	Description
System.Boolean	`true` if the dropdown list is in read-only mode; otherwise, `false`. The default is `false`.

Remarks

In read-only mode, the dropdown list popup can not be opened on click.

ShowClearButton

Gets or sets a value indicating whether to show or hide the clear button in the dropdown list. It helps to clear the selected value of a dropdown list on user intraction.

Declaration

public virtual bool ShowClearButton { get; set; }

Property Value

Type	Description
System.Boolean	`true` if show the clear button in the dropdown list; otherwise, `false`. The default is `false`.

Remarks

When the clear button is clicked, Value, and Index properties are reset to null.

TabIndex

Gets or sets the location of the SfDropDownList<TValue, TItem> component in the tab order.

Declaration

public int TabIndex { get; set; }

Property Value

Type	Description
System.Int32	The numeric index of the dropdown list in the tab order. The default value is `0`.

Value

Gets the value of the selected item in the dropdown list component. This will be used with two-way binding.

Declaration

public TValue Value { get; set; }

Property Value

Type	Description
TValue	The value of the selected item in the dropdown list component. The default is `null`.

Remarks

Use the Value property to specify or determine the value displayed in the SfDropDownList<TValue, TItem> component.

ValueChanged

Gets or sets a callback that trigger when the value changes.

Declaration

public EventCallback<TValue> ValueChanged { get; set; }

Property Value

Type	Description
Microsoft.AspNetCore.Components.EventCallback<TValue>	An event callback function.

ValueExpression

Gets or sets an expression that identifies the bound value in the DropDownListEvents<TValue, TItem> component.

Declaration

public Expression<Func<TValue>> ValueExpression { get; set; }

Property Value

Type
System.Linq.Expressions.Expression<System.Func<TValue>>

ValueTemplate

Gets or sets the customised design content and assigns it to the selected list item in the input element of the component.

Declaration

public RenderFragment<TItem> ValueTemplate { get; set; }

Property Value

Type	Description
Microsoft.AspNetCore.Components.RenderFragment<TItem>	The template content. The default value in `null`.

Examples

<SfDropDownList TItem="string" TValue="string" DataSource="@MyList">
    <DropDownListTemplates TItem="string">
        <ValueTemplate>
            <span> T-shirt size - @(context)</span>
        </ValueTemplate>
    </DropDownListTemplates>
</SfDropDownList>
@code{
    protected List<string> MyList = new List<string>() { "Small", "Medium", "Large" };
}

Width

Gets or sets the width of the SfDropDownList<TValue, TItem> component.

Declaration

public string Width { get; set; }

Property Value

Type	Description
System.String	The preferred width of the dropdown list in pixels or percentage value. The default value is `100%`.

Methods

BuildRenderTree(RenderTreeBuilder)

Declaration

protected override void BuildRenderTree(RenderTreeBuilder __builder)

Parameters

Type	Name	Description
Microsoft.AspNetCore.Components.Rendering.RenderTreeBuilder	__builder

ClearAllAsync(EventArgs, Boolean)

Task which used to clear all the items.

Declaration

protected virtual Task ClearAllAsync(EventArgs arguments = null, bool IsProgrammaticallyCleared = false)

Parameters

Type	Name	Description
System.EventArgs	arguments	Specifies the EventArgs arguments.
System.Boolean	IsProgrammaticallyCleared	Indicates whether the value is cleared manually or not, Default is false.

Returns

Type	Description
System.Threading.Tasks.Task	Task.

ClearAsync()

Clear out the selected values from the SfDropDownList<TValue, TItem> component and sets the Value and Index properties as null.

Declaration

public Task ClearAsync()

Returns

Type	Description
System.Threading.Tasks.Task	Task.

DisableItem(TValue)

Method to disable a specific item in the popup using its TValue.

Declaration

public Task DisableItem(TValue item)

Parameters

Type	Name	Description
TValue	item	The value or index of the item to be disabled.

Returns

Type
System.Threading.Tasks.Task

Remarks

This method disables a specific item in the popup based on the provided item. If the item is of type TValue, it represents the value associated with the item.

DisableItem(Int32)

Method to disable a specific item in the popup based on its index position.

Declaration

public Task DisableItem(int item)

Parameters

Type	Name	Description
System.Int32	item	The value or index of the item to be disabled.

Returns

Type
System.Threading.Tasks.Task

Remarks

This method disables a specific item in the popup based on the provided item. If the item is of type System.Int32, it represents the index of the item in the popup.

DropDownClickHandlerAsync()

Triggers while clicking the dropdown icon.

Declaration

protected Task DropDownClickHandlerAsync()

Returns

Type	Description
System.Threading.Tasks.Task	Task.

FilterAsync(IEnumerable<TItem>, Query, FieldSettingsModel)

To filter the data from given data source by using query.

Declaration

public Task FilterAsync(IEnumerable<TItem> dataSource, Query query = null, FieldSettingsModel fields = null)

Parameters

Type	Name	Description
System.Collections.Generic.IEnumerable<TItem>	dataSource	Specifies the data source.
Query	query	Specifies the query.
FieldSettingsModel	fields	Specifies the fields.

Returns

Type	Description
System.Threading.Tasks.Task	Task.

FilterInputKeyUpHandlerAync(KeyboardEventArgs)

Specifies the keyup event of filter event.

Declaration

protected Task FilterInputKeyUpHandlerAync(KeyboardEventArgs arguments)

Parameters

Type	Name	Description
Microsoft.AspNetCore.Components.Web.KeyboardEventArgs	arguments	Specifies the KeyboardEventArgs arguments.

Returns

Type	Description
System.Threading.Tasks.Task	Task.

FocusAsync()

Sets the focus to the SfDropDownList<TValue, TItem> component for interaction.

Declaration

public Task FocusAsync()

Returns

Type	Description
System.Threading.Tasks.Task	Task.

FocusOutAsync()

Remove the focus from the SfDropDownList<TValue, TItem> component, if the component is in focus state.

Declaration

public Task FocusOutAsync()

Returns

Type	Description
System.Threading.Tasks.Task	Task.

FocusOutHandlerAsync(FocusEventArgs, Boolean)

Triggers when the component get focused out.

Declaration

protected Task FocusOutHandlerAsync(FocusEventArgs arguments, bool isFilterinput = false)

Parameters

Type	Name	Description
Microsoft.AspNetCore.Components.Web.FocusEventArgs	arguments	Specifies the FocusEventArgs arguments.
System.Boolean	isFilterinput	Specifies whether it is a filter input or not.

Returns

Type	Description
System.Threading.Tasks.Task	Task.

GetDataByValue(TValue)

Retrieves all field values in the record that match the given value.

Declaration

public TItem GetDataByValue(TValue ddlValue)

Parameters

Type	Name	Description
TValue	ddlValue	TValue

Returns

Type	Description
TItem	The field value.

GetItemsAsync()

Retrieves all the list of items bound in the SfDropDownList<TValue, TItem> component.

Declaration

public Task<IEnumerable<TItem>> GetItemsAsync()

Returns

Type	Description
System.Threading.Tasks.Task<System.Collections.Generic.IEnumerable<TItem>>	Task.

HidePopupAsync()

Hides the SfDropDownList<TValue, TItem> popup list.

Declaration

public Task HidePopupAsync()

Returns

Type	Description
System.Threading.Tasks.Task	Task.

HideSpinnerAsync()

Hides the data loading spinner.

Declaration

public Task HideSpinnerAsync()

Returns

Type	Description
System.Threading.Tasks.Task	Task.

RefreshDataAsync()

Refreshes the popup list items. The method is useful if the popup list item changed externally.

Declaration

public Task RefreshDataAsync()

Returns

Type	Description
System.Threading.Tasks.Task	System.Threading.Tasks.Task.

SearchListAsync(KeyboardEventArgs)

Task which specifies the search list.

Declaration

protected virtual Task SearchListAsync(KeyboardEventArgs arguments = null)

Parameters

Type	Name	Description
Microsoft.AspNetCore.Components.Web.KeyboardEventArgs	arguments	Specifies the KeyboardEventArgs arguments.

Returns

Type	Description
System.Threading.Tasks.Task	Task.

SetCurrentViewDataAsync(Int32, Int32)

Declaration

protected override Task SetCurrentViewDataAsync(int virtualItemStartIndex, int virtualItemEndIndex)

Parameters

Type	Name	Description
System.Int32	virtualItemStartIndex
System.Int32	virtualItemEndIndex

Returns

Type
System.Threading.Tasks.Task

Overrides

Syncfusion.Blazor.DropDowns.SfDropDownBase<TItem>.SetCurrentViewDataAsync(System.Int32, System.Int32)

ShowPopupAsync()

Opens the dropdown popup that displays the list of items.

Declaration

public Task ShowPopupAsync()

Returns

Type	Description
System.Threading.Tasks.Task	Task.

ShowSpinnerAsync()

Shows the data loading spinner until the data populate the pop-up.

Declaration

public Task ShowSpinnerAsync()

Returns

Type	Description
System.Threading.Tasks.Task	Task.

UpdateDisableItem(TItem)

Updates the disabled status of a given item in the list.

Declaration

protected void UpdateDisableItem(TItem itemData)

Parameters

Type	Name	Description
TItem	itemData	The item to be updated.

Remarks

This method checks if the given item is not null and if it's not disabled. If so, it sets the disabled field of the item to true. It then updates the item in the ListData and disables the corresponding list item in the ListDataSource. If the item to be disabled is currently selected, it updates the value selection asynchronously.

UpdateIncrementalInfo(Int32, Int32, Boolean)

Declaration

protected Task UpdateIncrementalInfo(int startIndex, int endIndex, bool isIncremental = true)

Parameters

Type	Name	Description
System.Int32	startIndex
System.Int32	endIndex
System.Boolean	isIncremental

Returns

Type
System.Threading.Tasks.Task

UpdateIncrementalItemIndex(Int32, Int32)

Declaration

protected void UpdateIncrementalItemIndex(int startIndex, int endIndex)

Parameters

Type	Name	Description
System.Int32	startIndex
System.Int32	endIndex

UpdateMainData()

Task which update main data.

Declaration

protected virtual void UpdateMainData()

UpdateValueAsync()

Task which updates the value.

Declaration

protected virtual Task UpdateValueAsync()

Returns

Type	Description
System.Threading.Tasks.Task	Task.

Implements

Syncfusion.Blazor.DropDowns.IVirtualList<T>