Class FormComponent<T>

Base class for all Radzen form input components providing data binding, validation, and change event capabilities. FormComponent integrates with Blazor's EditContext for form validation and provides common functionality for all input controls. This is the base class for components like RadzenTextBox, RadzenCheckBox, RadzenDropDown, RadzenDatePicker, etc. Provides @bind-Value support for two-way binding, integration with Blazor EditContext and validators, Change and ValueChanged callbacks, Disable property to prevent user interaction, Placeholder text for empty inputs, Name property for validation and label association, and TabIndex for keyboard navigation control. Components inheriting from FormComponent automatically work with RadzenTemplateForm and validators.

Inheritance

object

ComponentBase

RadzenComponent

FormComponent<T>

RadzenCheckBoxList<TValue>

RadzenCheckBox<TValue>

RadzenColorPicker

RadzenFileInput<TValue>

RadzenHtmlEditor

RadzenRadioButtonList<TValue>

RadzenRating

RadzenSecurityCode

RadzenSelectBar<TValue>

RadzenSlider<TValue>

RadzenSwitch

RadzenTextArea

FormComponentWithAutoComplete<T>

Implements

IComponent

IHandleEvent

IHandleAfterRender

IDisposable

IRadzenFormComponent

Inherited Members

RadzenComponent.OnMouseEnter()

RadzenComponent.OnMouseLeave()

RadzenComponent.GetCssClass()

RadzenComponent.GetId()

RadzenComponent.GetComponentCssClass()

RadzenComponent.Debounce(Func<Task>, int)

RadzenComponent.OnInitialized()

RadzenComponent.OnAfterRenderAsync(bool)

RadzenComponent.RaiseContextMenu(MouseEventArgs)

RadzenComponent.RaiseMouseEnter()

RadzenComponent.AddContextMenu()

RadzenComponent.RaiseMouseLeave()

RadzenComponent.Attributes

RadzenComponent.Element

RadzenComponent.MouseEnter

RadzenComponent.MouseLeave

RadzenComponent.ContextMenu

RadzenComponent.Culture

RadzenComponent.DefaultCulture

RadzenComponent.Style

RadzenComponent.Visible

RadzenComponent.UniqueID

RadzenComponent.JSRuntime

RadzenComponent.IsJSRuntimeAvailable

RadzenComponent.Reference

RadzenComponent.CurrentStyle

ComponentBase.BuildRenderTree(RenderTreeBuilder)

ComponentBase.OnInitializedAsync()

ComponentBase.OnParametersSet()

ComponentBase.OnParametersSetAsync()

ComponentBase.StateHasChanged()

ComponentBase.ShouldRender()

ComponentBase.OnAfterRender(bool)

ComponentBase.InvokeAsync(Action)

ComponentBase.InvokeAsync(Func<Task>)

ComponentBase.DispatchExceptionAsync(Exception)

object.GetType()

object.MemberwiseClone()

object.ToString()

object.Equals(object)

object.Equals(object, object)

object.ReferenceEquals(object, object)

object.GetHashCode()

Namespace: Radzen

Assembly: Radzen.Blazor.dll

Syntax

public class FormComponent<T> : RadzenComponent, IComponent, IHandleEvent, IHandleAfterRender, IDisposable, IRadzenFormComponent

Type Parameters

Name	Description
T	The type of the component's bound value (string, int, DateTime, etc.).

Constructors

FormComponent()

Base class for all Radzen form input components providing data binding, validation, and change event capabilities. FormComponent integrates with Blazor's EditContext for form validation and provides common functionality for all input controls. This is the base class for components like RadzenTextBox, RadzenCheckBox, RadzenDropDown, RadzenDatePicker, etc. Provides @bind-Value support for two-way binding, integration with Blazor EditContext and validators, Change and ValueChanged callbacks, Disable property to prevent user interaction, Placeholder text for empty inputs, Name property for validation and label association, and TabIndex for keyboard navigation control. Components inheriting from FormComponent automatically work with RadzenTemplateForm and validators.

Declaration

public FormComponent()

Fields

_value

The value

Declaration

protected T _value

Field Value

Type	Description
T

Properties

Change

Gets or sets the change.

Declaration

[Parameter]
public EventCallback<T> Change { get; set; }

Property Value

Type	Description
EventCallback<T>	The change.

CurrentPlaceholder

Gets the current placeholder. Returns empty string if this component is inside a RadzenFormField.

Declaration

protected string CurrentPlaceholder { get; }

Property Value

Type	Description
string

Disabled

Gets or sets a value indicating whether this FormComponent<T> is disabled.

Declaration

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

Property Value

Type	Description
bool	true if disabled; otherwise, false.

EditContext

Gets or sets the edit context.

Declaration

[CascadingParameter]
public EditContext EditContext { get; set; }

Property Value

Type	Description
EditContext	The edit context.

FieldIdentifier

Gets the field identifier.

Declaration

[Parameter]
public FieldIdentifier FieldIdentifier { get; set; }

Property Value

Type	Description
FieldIdentifier	The field identifier.

Form

Gets or sets the form.

Declaration

[CascadingParameter]
public IRadzenForm Form { get; set; }

Property Value

Type	Description
IRadzenForm	The form.

FormFieldContext

Provides support for RadzenFormField integration.

Declaration

[CascadingParameter]
public IFormFieldContext FormFieldContext { get; set; }

Property Value

Type	Description
IFormFieldContext

HasValue

Gets a value indicating whether this instance has value.

Declaration

public virtual bool HasValue { get; }

Property Value

Type	Description
bool	true if this instance has value; otherwise, false.

IsBound

Gets a value indicating whether this instance is bound.

Declaration

public bool IsBound { get; }

Property Value

Type	Description
bool	true if this instance is bound; otherwise, false.

Name

Gets or sets the unique name identifier for this form component. Used for validation association (linking with validators and labels) and for identifying the field in form submission. This name should be unique within the form and match the Component property of associated validators/labels.

Declaration

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

Property Value

Type	Description
string	The component name.

Placeholder

Gets or sets the placeholder.

Declaration

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

Property Value

Type	Description
string	The placeholder.

TabIndex

Gets or sets the tab order index for keyboard navigation. Controls the order in which fields receive focus when the user presses the Tab key. Lower values receive focus first. Use -1 to exclude from tab navigation.

Declaration

[Parameter]
public int TabIndex { get; set; }

Property Value

Type	Description
int	The tab index. Default is 0 (natural tab order).

Value

Gets or sets the value.

Declaration

[Parameter]
public virtual T Value { get; set; }

Property Value

Type	Description
T	The value.

ValueChanged

Gets or sets the value changed.

Declaration

[Parameter]
public EventCallback<T> ValueChanged { get; set; }

Property Value

Type	Description
EventCallback<T>	The value changed.

ValueExpression

Gets or sets the value expression.

Declaration

[Parameter]
public Expression<Func<T>> ValueExpression { get; set; }

Property Value

Type	Description
Expression<Func<T>>	The value expression.

Methods

Dispose()

Disposes this instance.

Declaration

public override void Dispose()

Overrides

RadzenComponent.Dispose()

FocusAsync()

Sets the focus.

Declaration

public virtual ValueTask FocusAsync()

Returns

Type	Description
ValueTask

GetClassList(string)

Gets the class list.

Declaration

protected ClassList GetClassList(string className)

Parameters

Type	Name	Description
string	className	Name of the class.

Returns

Type	Description
ClassList	ClassList.

GetValue()

Gets the value.

Declaration

public object GetValue()

Returns

Type	Description
object	System.Object.

OnContextMenu(MouseEventArgs)

Handles the ContextMenu event.

Declaration

public override Task OnContextMenu(MouseEventArgs args)

Parameters

Type	Name	Description
MouseEventArgs	args	The MouseEventArgs instance containing the event data.

Returns

Type	Description
Task	Task.

Overrides

RadzenComponent.OnContextMenu(MouseEventArgs)

SetParametersAsync(ParameterView)

Sets the parameters asynchronous.

Declaration

public override Task SetParametersAsync(ParameterView parameters)

Parameters

Type	Name	Description
ParameterView	parameters	The parameters.

Returns

Type	Description
Task	Task.

Overrides

RadzenComponent.SetParametersAsync(ParameterView)

Implements

IComponent

IHandleEvent

IHandleAfterRender

IDisposable

IRadzenFormComponent