What is Blazor in ASP.NET?
a) A library for server-side development
b) A framework for building interactive web UIs
c) A tool for database management
d) A language for front-end development
Answer: b) A framework for building interactive web UIs
Which Blazor hosting model runs the application on the client-side?
a) Blazor Server
b) Blazor WebAssembly
c) Blazor Desktop
d) Blazor Cloud
Answer: b) Blazor WebAssembly
What does the @page directive do in a Blazor component?
a) Defines a route for the component
b) Specifies the data-binding context
c) Sets the layout for the component
d) Imports a namespace
Answer: a) Defines a route for the component
In Blazor, what is the purpose of the
@code
block?
a) To define CSS styles
b) To write inline JavaScript
c) To write C# code in a Razor component
d) To configure routing
Answer: c) To write C# code in a Razor component
Which method is used to handle form submissions in Blazor?
a)
OnSubmit
b)
OnClick
c)
OnChange
d)
OnValidSubmit
Answer: d)
OnValidSubmit
What is the default file extension for a Blazor component?
a) .cshtml
b) .razor
c) .html
d) .cs
Answer: b) .razor
Which Blazor component lifecycle method is called when the component is first initialized?
a)
OnInit
b)
OnInitialized
c)
OnParametersSet
d)
OnAfterRender
Answer: b)
OnInitialized
How can you pass parameters to a Blazor component?
a) Using URL parameters
b) Using
@parameter
directives
c) Using attributes in the component tag
d) Using HTTP POST requests
Answer: c) Using attributes in the component tag
What is the purpose of the
@inject
directive in Blazor?
a) To inject services into a component
b) To create a new component instance
c) To define component routing
d) To include JavaScript libraries
Answer: a) To inject services into a component
Which method is used to perform asynchronous data loading in Blazor?
a)
OnInitialized
b)
OnInitializedAsync
c)
OnAfterRender
d)
OnAfterRenderAsync
Answer: b)
OnInitializedAsync
What type of binding is used to bind a form input to a property in Blazor?
a) Event binding
b) Two-way binding
c) One-way binding
d) Data binding
Answer: b) Two-way binding
In Blazor, how do you define a route for a component?
a) Using the
Route
attribute
b) Using the
@page
directive
c) Configuring routes in
Startup.cs
d) Declaring routes in
appsettings.json
Answer: b) Using the
@page
directive
What is the purpose of the
@layout
directive in a Blazor component?
a) To specify a layout component for the page
b) To define CSS styles for the component
c) To configure the data context
d) To handle component routing
Answer: a) To specify a layout component for the page
What is the purpose of the
StateHasChanged
method in Blazor?
a) To update the UI after data changes
b) To trigger a re-render of the component
c) To call a server-side API
d) To initialize component state
Answer: b) To trigger a re-render of the component
Which of the following is NOT a valid Blazor component event handler?
a)
OnClick
b)
OnChange
c)
OnSubmit
d)
OnRender
Answer: d)
OnRender
What is the primary purpose of the
HttpClient
service in Blazor?
a) To manage client-side state
b) To perform HTTP requests to APIs
c) To handle user input
d) To render components
Answer: b) To perform HTTP requests to APIs
How do you access a service registered in the dependency injection container in Blazor?
a) By using
@service
directive
b) By injecting it into the component constructor
c) By calling
GetService
method
d) By using the
@inject
directive
Answer: d) By using the
@inject
directive
What is the role of
RenderFragment
in Blazor?
a) To define a componentβs layout
b) To hold a piece of UI that can be rendered
c) To configure component routing
d) To manage component state
Answer: b) To hold a piece of UI that can be rendered
Which Blazor component lifecycle method is called after the component has rendered?
a)
OnInitialized
b)
OnParametersSet
c)
OnAfterRender
d)
OnInitializedAsync
Answer: c)
OnAfterRender
How do you perform navigation programmatically in Blazor?
a) Using the
NavigateTo
method of
NavigationManager
b) Using
@route
directive
c) Using
HttpClient
d) By modifying the
href
attribute of a link
Answer: a) Using the
NavigateTo
method of
NavigationManager
Which directive is used to include another Razor component in a Blazor page?
a)
@include
b)
@component
c)
@using
d)
@page
Answer: c)
@using
What does the
OnParametersSet
lifecycle method do in a Blazor component?
a) Initializes component state
b) Handles parameter changes
c) Performs asynchronous operations
d) Renders the component
Answer: b) Handles parameter changes
What is the purpose of
EventCallback
in Blazor?
a) To handle component events
b) To bind data to UI components
c) To define routes for components
d) To inject services
Answer: a) To handle component events
How can you handle form validation in Blazor?
a) By using
ValidationMessage
component
b) By creating custom validators
c) By using data annotations and
DataAnnotationsValidator
d) By configuring validation in
Startup.cs
Answer: c) By using data annotations and
DataAnnotationsValidator
What is the role of
CascadingParameter
in Blazor?
a) To pass parameters to nested components
b) To define global styles
c) To manage component state
d) To configure routing
Answer: a) To pass parameters to nested components
How do you define a custom component in Blazor?
a) By creating a new
.html
file
b) By creating a new
.cs
file
c) By creating a
.razor
file with C# code
d) By configuring it in
Startup.cs
Answer: c) By creating a
.razor
file with C# code
Which Blazor directive is used to specify a componentβs layout?
a)
@page
b)
@layout
c)
@model
d)
@using
Answer: b)
@layout
What is the purpose of the
OnAfterRenderAsync
method in Blazor?
a) To handle asynchronous operations after the component has rendered
b) To initialize component state
c) To update UI elements synchronously
d) To handle parameter changes
Answer: a) To handle asynchronous operations after the component has rendered
How do you set a default value for a parameter in a Blazor component?
a) By specifying the value in the constructor
b) By setting the value in the
@code
block
c) By using the
default
keyword
d) By defining a default parameter in the component tag
Answer: b) By setting the value in the
@code
block
What is the purpose of
@bind
in Blazor?
a) To bind a component to a service
b) To create a one-way data binding
c) To create a two-way data binding for form inputs
d) To define a route
Answer: c) To create a two-way data binding for form inputs
How can you pass a value from a parent component to a child component in Blazor?
a) By using a parameter attribute
b) By using a cascading parameter
c) By setting a property in the parentβs constructor
d) By using a static field
Answer: a) By using a parameter attribute
What does the
OnInitialized
lifecycle method do in Blazor?
a) Initializes component parameters
b) Performs component rendering
c) Initializes component state
d) Handles form submissions
Answer: c) Initializes component state
What is the use of
RenderMode
in Blazor Server-Side?
a) To define the rendering strategy for components
b) To configure the client-side JavaScript
c) To manage server-side state
d) To specify the hosting environment
Answer: a) To define the rendering strategy for components
Which component is used to display validation messages in Blazor?
a)
ValidationMessage
b)
ErrorDisplay
c)
FormValidator
d)
DataError
Answer: a)
ValidationMessage
How do you perform data binding for a select element in Blazor?
a) Using
@bind
directive with a
select
element
b) Using
@foreach
to generate options
c) Using
@data
directive
d) By setting properties in the
@code
block
Answer: a) Using
@bind
directive with a
select
element
What is the purpose of
@onchange
in a Blazor component?
a) To define a CSS style
b) To handle change events for form inputs
c) To specify a layout
d) To configure routing
Answer: b) To handle change events for form inputs
How can you use JavaScript interop in Blazor?
a) By using
@inject
directive
b) By defining JavaScript functions in
wwwroot
and calling them using
IJSRuntime
c) By adding JavaScript directly to
.razor
files
d) By configuring JavaScript libraries in
Startup.cs
Answer: b) By defining JavaScript functions in
wwwroot
and calling them using
IJSRuntime
What does
IJSRuntime
interface provide in Blazor?
a) Methods to interact with JavaScript from .NET code
b) Methods to manage server-side state
c) Methods for component rendering
d) Methods for dependency injection
Answer: a) Methods to interact with JavaScript from .NET code
What is the role of the
OnParametersSetAsync
lifecycle method in Blazor?
a) To handle asynchronous operations after parameters have been set
b) To initialize component state
c) To update UI elements
d) To configure routing
Answer: a) To handle asynchronous operations after parameters have been set
How do you dynamically load a component in Blazor?
a) Using
ComponentLoader
service
b) By using
DynamicComponent
class
c) By creating a new instance of the component manually
d) By using
@bind
directive
Answer: b) By using
DynamicComponent
class
What is the purpose of
@key
directive in Blazor?
a) To define a unique key for rendering lists
b) To encrypt data before rendering
c) To specify the layout of a component
d) To handle component parameters
Answer: a) To define a unique key for rendering lists
How do you handle user input validation in Blazor?
a) Using
ValidationSummary
component
b) Using data annotations and
DataAnnotationsValidator
c) By defining custom validation functions in
@code
block
d) By configuring validation in
Startup.cs
Answer: b) Using data annotations and
DataAnnotationsValidator
What is the purpose of
OnAfterRender
lifecycle method in Blazor?
a) To perform actions after the component has rendered
b) To initialize component state
c) To handle parameter changes
d) To configure routing
Answer: a) To perform actions after the component has rendered
How do you define a route parameter in Blazor?
a) By using
@parameter
directive
b) By defining parameters in the URL within the
@page
directive
c) By creating query strings
d) By configuring routes in
Startup.cs
Answer: b) By defining parameters in the URL within the
@page
directive
Which Blazor lifecycle method is called when a componentβs parameters are set?
a)
OnInitialized
b)
OnParametersSet
c)
OnAfterRender
d)
OnInitializedAsync
Answer: b)
OnParametersSet
What is the use of the
@functions
directive in Blazor?
a) To define C# functions within a Razor component
b) To declare component styles
c) To configure routing
d) To manage JavaScript interop
Answer: a) To define C# functions within a Razor component
How can you use dependency injection in Blazor?
a) By using
@inject
directive in Razor components
b) By creating services in
Startup.cs
c) By manually passing dependencies to components
d) By configuring services in
appsettings.json
Answer: a) By using
@inject
directive in Razor components
What does the
OnInitializedAsync
lifecycle method do in Blazor?
a) Initializes component state asynchronously
b) Handles form submissions
c) Updates UI elements
d) Configures routing
Answer: a) Initializes component state asynchronously
How do you handle navigation events in Blazor?
a) Using
NavigationManager
service
b) By modifying the URL directly
c) By configuring routes in
Startup.cs
d) By using JavaScript interop
Answer: a) Using
NavigationManager
service
What is the function of
@using
directive in Blazor?
a) To include namespaces in a Razor component
b) To define component parameters
c) To specify layout
d) To manage JavaScript interop
Answer: a) To include namespaces in a Razor component
Which Blazor component is used to create a form?
a)
EditForm
b)
Form
c)
InputForm
d)
SubmitForm
Answer: a)
EditForm
How do you define a template in Blazor?
a) By using the
Template
directive
b) By creating a new
.razor
file
c) By defining
RenderFragment
d) By specifying the template in
Startup.cs
Answer: c) By defining
RenderFragment
What is
IServiceProvider
used for in Blazor?
a) To resolve and provide services to components
b) To handle component rendering
c) To manage JavaScript interop
d) To define component routes
Answer: a) To resolve and provide services to components