Table of Contents

Class BOBDropdownContainer<TValue>

Namespace
BlazOrbit.Components.Forms.Dropdown
Assembly
BlazOrbit.dll
public class BOBDropdownContainer<TValue> : BOBInputComponentBase<TValue, BOBDropdownContainer<TValue>, BOBInputVariant>, IHasReadOnly, IHasDisabled, IHasRequired, IHasError, IVariantComponent<BOBInputVariant>, IVariantComponent, IHasSize, IHasLoading, IHasShadow, IHasElevation, IHasColor, IHasBackgroundColor, IHasPrefix, IHasSuffix, IInputFamilyComponent

Type Parameters

TValue
Inheritance
object
ComponentBase
InputBase<TValue>
BOBDropdownContainer<TValue>
Implements
Inherited Members

Constructors

BOBDropdownContainer() 

public BOBDropdownContainer()

Properties

AriaMultiselectable

When true, advertises the menu as multi-selectable to assistive tech.

[Parameter]
public bool AriaMultiselectable { get; set; }

Property Value

bool

AriaRole

ARIA role applied to the popup menu (defaults to listbox; use tree or menu for non-list semantics).

[Parameter]
public string AriaRole { get; set; }

Property Value

string

BackgroundColor

Background color of the trigger. Accepts any valid CSS color value.

[Parameter]
public string? BackgroundColor { get; set; }

Property Value

string

BuiltInTemplates 

protected override IReadOnlyDictionary<BOBInputVariant, Func<BOBDropdownContainer<TValue>, RenderFragment>> BuiltInTemplates { get; }

Property Value

IReadOnlyDictionary<BOBInputVariant, Func<BOBDropdownContainer<TValue>, RenderFragment>>

Color

Text color of the trigger. Accepts any valid CSS color value.

[Parameter]
public string? Color { get; set; }

Property Value

string

ComponentId 

public string ComponentId { get; }

Property Value

string

DefaultVariant

Default variant used when no explicit variant is specified.

public override BOBInputVariant DefaultVariant { get; }

Property Value

BOBInputVariant

DisplayValue 

[Parameter]
[EditorRequired]
public string DisplayValue { get; set; }

Property Value

string

Elevation

Material Design elevation level (0–24) applied to the menu surface. Sets a derived shadow and lifts the surface in dark mode via a tint overlay. Overridden by Shadow.

[Parameter]
public int? Elevation { get; set; }

Property Value

int?

HasValue

When true, HasValue is active.

[Parameter]
public bool HasValue { get; set; }

Property Value

bool

HelperText

Helper text displayed below the component for additional context.

[Parameter]
public string? HelperText { get; set; }

Property Value

string

IsOpen 

public bool IsOpen { get; }

Property Value

bool

Label

Floating label displayed above the component.

[Parameter]
public string? Label { get; set; }

Property Value

string

Loading

When true, the trigger shows a loading indicator and ignores activation.

[Parameter]
public bool Loading { get; set; }

Property Value

bool

LoadingIndicatorVariant

Variant of the loading indicator shown when Loading is true.

[Parameter]
public BOBLoadingIndicatorVariant LoadingIndicatorVariant { get; set; }

Property Value

BOBLoadingIndicatorVariant

MenuContent

Render fragment that emits the popup menu content (option list, tree, etc.).

[Parameter]
public RenderFragment? MenuContent { get; set; }

Property Value

RenderFragment

OnClosed

Raised when the Closed event occurs.

[Parameter]
public EventCallback OnClosed { get; set; }

Property Value

EventCallback

OnKeyboardNavigation

Raised when the KeyboardNavigation event occurs.

[Parameter]
public EventCallback<DropdownKeyboardEventArgs> OnKeyboardNavigation { get; set; }

Property Value

EventCallback<DropdownKeyboardEventArgs>

OnOpened

Raised when the Opened event occurs.

[Parameter]
public EventCallback OnOpened { get; set; }

Property Value

EventCallback

OnValueChanged

Raised when the ValueChanged event occurs.

[Parameter]
public EventCallback<TValue> OnValueChanged { get; set; }

Property Value

EventCallback<TValue>

Placeholder

Placeholder text shown when the component is empty.

[Parameter]
public string? Placeholder { get; set; }

Property Value

string

Placement

Preferred placement of the popup menu relative to the trigger.

[Parameter]
public DropdownPlacement Placement { get; set; }

Property Value

DropdownPlacement

PrefixBackgroundColor

PrefixBackground color. Accepts any valid CSS color value.

[Parameter]
public string? PrefixBackgroundColor { get; set; }

Property Value

string

PrefixColor

Prefix color. Accepts any valid CSS color value.

[Parameter]
public string? PrefixColor { get; set; }

Property Value

string

PrefixIcon

Material icon name for the Prefix.

[Parameter]
public IconKey? PrefixIcon { get; set; }

Property Value

IconKey?

PrefixText

Text displayed before the trigger value.

[Parameter]
public string? PrefixText { get; set; }

Property Value

string

Shadow

Shadow style applied to the trigger container. Wins over Elevation when both are set.

[Parameter]
public ShadowStyle? Shadow { get; set; }

Property Value

ShadowStyle

Size

Visual size of the dropdown trigger.

[Parameter]
public BOBSize Size { get; set; }

Property Value

BOBSize

SuffixBackgroundColor

SuffixBackground color. Accepts any valid CSS color value.

[Parameter]
public string? SuffixBackgroundColor { get; set; }

Property Value

string

SuffixColor

Suffix color. Accepts any valid CSS color value.

[Parameter]
public string? SuffixColor { get; set; }

Property Value

string

SuffixIcon

Material icon name for the Suffix.

[Parameter]
public IconKey? SuffixIcon { get; set; }

Property Value

IconKey?

SuffixText

Text displayed after the trigger value.

[Parameter]
public string? SuffixText { get; set; }

Property Value

string

Methods

BuildComponentDataAttributes(Dictionary<string, object>) 

public override void BuildComponentDataAttributes(Dictionary<string, object> dataAttributes)

Parameters

dataAttributes Dictionary<string, object>

BuildRenderTree(RenderTreeBuilder)

Renders the component to the supplied Microsoft.AspNetCore.Components.Rendering.RenderTreeBuilder.

protected override void BuildRenderTree(RenderTreeBuilder __builder)

Parameters

__builder RenderTreeBuilder

CloseAsync() 

public Task CloseAsync()

Returns

Task

DisposeAsync()

Async disposal path. Blazor invokes this first when the component is unmounted because the type implements System.IAsyncDisposable; it tears down the JS-side behavior instance via BlazOrbit.Abstractions.BOBComponentPipeline.DisposeBehaviorAsync().

public override ValueTask DisposeAsync()

Returns

ValueTask

Remarks

Both this method and Dispose(bool) run on disposal — Blazor calls DisposeAsync for the async work and the framework's System.IDisposable contract still invokes Dispose(true) afterward. The split is intentional: async work (JS interop teardown) lives here, sync work (event unsubscribe) lives in Dispose(true). Both set IsDisposed so derived components can guard post-await continuations regardless of which path runs first.

FocusSearchInputAsync() 

public Task FocusSearchInputAsync()

Returns

Task

OnAfterRenderAsync(bool)

Method invoked after each time the component has been rendered interactively and the UI has finished updating (for example, after elements have been added to the browser DOM). Any Microsoft.AspNetCore.Components.ElementReference fields will be populated by the time this runs.

This method is not invoked during prerendering or server-side rendering, because those processes are not attached to any live browser DOM and are already complete before the DOM is updated.

Note that the component does not automatically re-render after the completion of any returned System.Threading.Tasks.Task, because that would cause an infinite render loop.

protected override Task OnAfterRenderAsync(bool firstRender)

Parameters

firstRender bool

Set to true if this is the first time Microsoft.AspNetCore.Components.ComponentBase.OnAfterRender(bool) has been invoked on this component instance; otherwise false.

Returns

Task

A System.Threading.Tasks.Task representing any asynchronous operation.

Remarks

The Microsoft.AspNetCore.Components.ComponentBase.OnAfterRender(bool) and Microsoft.AspNetCore.Components.ComponentBase.OnAfterRenderAsync(bool) lifecycle methods are useful for performing interop, or interacting with values received from @ref. Use the firstRender parameter to ensure that initialization work is only performed once.

OpenAsync() 

public Task OpenAsync()

Returns

Task

ToggleAsync() 

public Task ToggleAsync()

Returns

Task

TryParseValueFromString(string?, out TValue, out string)

Parses a string to create an instance of TValue. Derived classes can override this to change how Microsoft.AspNetCore.Components.Forms.InputBase<TValue>.CurrentValueAsString interprets incoming values.

protected override bool TryParseValueFromString(string? value, out TValue result, out string validationErrorMessage)

Parameters

value string

The string value to be parsed.

result TValue

An instance of TValue.

validationErrorMessage string

If the value could not be parsed, provides a validation error message.

Returns

bool

True if the value could be parsed; otherwise false.

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