What is Blazor in the context of ASP.NET?
a) A front-end JavaScript framework
b) A tool for database management
c) A framework for building interactive web UIs with C#
d) A server-side library for handling HTTP requests
Answer: c) A framework for building interactive web UIs with C#
Which of the following Blazor hosting models allows for client-side execution?
a) Blazor Server
b) Blazor WebAssembly
c) Blazor Desktop
d) Blazor Cloud
Answer: b) Blazor WebAssembly
What file extension is commonly used for Blazor components?
a) .html
b) .js
c) .razor
d) .cshtml
Answer: c) .razor
Which Blazor hosting model executes the app entirely on the server?
a) Blazor WebAssembly
b) Blazor Server
c) Blazor Static
d) Blazor API
Answer: b) Blazor Server
In Blazor, what does the @page directive do in a component file?
a) Defines the component’s CSS styles
b) Sets the layout for the component
c) Specifies the route for the component
d) Configures the component’s data binding
Answer: c) Specifies the route for the component
How do you define a route parameter in a Blazor component?
a) By using the @route directive
b) By specifying parameters in the @page directive
c) By defining query strings in the URL
d) By using the @parameter directive
Answer: b) By specifying parameters in the @page directive
What is the purpose of the @code block in a Blazor component?
a) To include JavaScript code
b) To define the component’s CSS
c) To write C# code within a Razor component
d) To configure component routing
Answer: c) To write C# code within a Razor component
How can you inject a service into a Blazor component?
a) By using the @inject directive
b) By using the @service directive
c) By defining the service in the component’s constructor
d) By setting the service in Startup.cs
Answer: a) By using the @inject directive
Which lifecycle method is called when a Blazor component is first initialized?
a) OnInitialized
b) OnParametersSet
c) OnAfterRender
d) OnRender
Answer: a) OnInitialized
How do you handle asynchronous data operations in Blazor?
a) By using the OnInitialized method
b) By using the OnInitializedAsync method
c) By using Task.Run
d) By using JavaScript interop
Answer: b) By using the OnInitializedAsync method
What is the purpose of the @layout directive in a Blazor component?
a) To specify the layout for the component
b) To define the component’s route
c) To manage state in the component
d) To include external CSS
Answer: a) To specify the layout for the component
What does the StateHasChanged method do in Blazor?
a) Updates the component’s state
b) Triggers a re-render of the component
c) Initializes the component
d) Loads external resources
Answer: b) Triggers a re-render of the component
Which directive is used to include other Razor components in a Blazor page?
a) @include
b) @component
c) @using
d) @reference
Answer: c) @using
What is the purpose of RenderFragment in Blazor?
a) To define a component’s layout
b) To create reusable pieces of UI
c) To manage data binding
d) To handle routing
Answer: b) To create reusable pieces of UI
Which lifecycle method is called after a Blazor component has rendered?
a) OnInitialized
b) OnParametersSet
c) OnAfterRender
d) OnInitializedAsync
Answer: c) OnAfterRender
What is the HttpClient service used for in Blazor?
a) To handle component rendering
b) To perform HTTP requests to APIs
c) To manage JavaScript interop
d) To inject services into components
Answer: b) To perform HTTP requests to APIs
How do you perform navigation in a Blazor application?
a) By using the NavigationManager service
b) By directly modifying the URL
c) By using HttpClient
d) By using JavaScript interop
Answer: a) By using the NavigationManager service
What is the purpose of the OnParametersSet lifecycle method in a Blazor component?
a) To initialize component state
b) To handle parameter changes
c) To render the component
d) To update UI elements
Answer: b) To handle parameter changes
How do you handle form submissions in Blazor?
a) Using the OnSubmit method
b) Using the OnValidSubmit method
c) Using OnChange method
d) Using JavaScript interop
Answer: b) Using the OnValidSubmit method
What does the @bind directive do in Blazor?
a) Creates one-way data binding
b) Creates two-way data binding for form elements
c) Specifies a component’s route
d) Defines a component’s layout
Answer: b) Creates two-way data binding for form elements
How do you pass parameters to a Blazor component?
a) Using attributes in the component tag
b) Using URL parameters
c) Using query strings
d) By defining parameters in Startup.cs
Answer: a) Using attributes in the component tag
What does the @inject directive in Blazor do?
a) Injects services into a component
b) Creates a new instance of a component
c) Defines a route for a component
d) Manages JavaScript interop
Answer: a) Injects services into a component
Which method is used for component initialization in Blazor?
a) OnInitialized
b) OnAfterRender
c) OnParametersSet
d) OnSubmit
Answer: a) OnInitialized
What does the @key directive do in Blazor?
a) Defines a unique key for rendering list items
b) Encrypts data for security
c) Specifies a component’s layout
d) Manages routing
Answer: a) Defines a unique key for rendering list items
How do you create a custom component in Blazor?
a) By creating a .html file
b) By creating a .cs file
c) By creating a .razor file with C# code
d) By configuring in Startup.cs
Answer: c) By creating a .razor file with C# code
What is the purpose of the OnAfterRenderAsync lifecycle method?
a) To handle asynchronous operations after rendering
b) To initialize component state
c) To handle parameter changes
d) To configure routing
Answer: a) To handle asynchronous operations after rendering
What does the CascadingParameter attribute do in Blazor?
a) Passes parameters to descendant components
b) Defines a global style
c) Manages component state
d) Configures routing
Answer: a) Passes parameters to descendant components
How do you use JavaScript interop in Blazor?
a) By defining JavaScript functions in wwwroot and calling them with IJSRuntime
b) By embedding JavaScript directly in Razor components
c) By configuring JavaScript in Startup.cs
d) By using @inject directive
Answer: a) By defining JavaScript functions in wwwroot and calling them with IJSRuntime
What is IJSRuntime used for in Blazor?
a) To call JavaScript functions from .NET
b) To handle component rendering
c) To manage component state
d) To configure routing
Answer: a) To call JavaScript functions from .NET
How do you define a layout for a Blazor component?
a) By using the @page directive
b) By using the @layout directive
c) By configuring it in Startup.cs
d) By defining it in appsettings.json
Answer: b) By using the @layout directive
Which lifecycle method handles asynchronous operations after component rendering?
a) OnInitializedAsync
b) OnAfterRenderAsync
c) OnParametersSetAsync
d) OnInitialized
Answer: b) OnAfterRenderAsync
What is the role of RenderFragment in Blazor components?
a) To create reusable pieces of UI
b) To define component routing
c) To manage component state
d) To handle form submissions
Answer: a) To create reusable pieces of UI
How do you manage form validation in Blazor?
a) Using data annotations and DataAnnotationsValidator
b) By defining custom validation functions
c) By using ValidationSummary component
d) By configuring validation in Startup.cs
Answer: a) Using data annotations and DataAnnotationsValidator
What is the purpose of the OnInitialized method in a Blazor component?
a) To perform component initialization
b) To handle parameter changes
c) To perform rendering actions
d) To handle user input
Answer: a) To perform component initialization
How do you enable interactive web functionality in Blazor WebAssembly?
a) By configuring services in Startup.cs
b) By using C# and .NET code running in the browser
c) By setting up JavaScript interop
d) By defining component layouts
Answer: b) By using C# and .NET code running in the browser
What does the @bind directive facilitate in Blazor?
a) One-way data binding
b) Two-way data binding
c) Component routing
d) Component styling
Answer: b) Two-way data binding
Which service is commonly used for navigation in Blazor?
a) HttpClient
b) IServiceProvider
c) NavigationManager
d) IJSRuntime
Answer: c) NavigationManager
What is ComponentBase used for in Blazor?
a) To create a base class for Blazor components
b) To manage component state
c) To handle HTTP requests
d) To define component routing
Answer: a) To create a base class for Blazor components
How can you render a component conditionally in Blazor?
a) Using if statements in Razor markup
b) By setting visibility in Startup.cs
c) By defining routing parameters
d) By using JavaScript interop
Answer: a) Using if statements in Razor markup
What is the role of RenderFragment<T> in Blazor?
a) To define generic UI fragments
b) To create reusable UI components
c) To manage data binding
d) To handle form validation
Answer: a) To define generic UI fragments
How do you ensure a Blazor component updates its UI after changes?
a) By calling StateHasChanged method
b) By using @bind directive
c) By using OnParametersSet method
d) By configuring routing
Answer: a) By calling StateHasChanged method
What does the CascadingValue component do in Blazor?
a) Provides a value to all descendant components
b) Defines global styles
c) Manages component state
d) Handles form validation
Answer: a) Provides a value to all descendant components
How do you pass parameters to a component using route parameters?
a) By defining parameters in the @page directive and accessing them via RouteData
b) By using query strings in the URL
c) By defining parameters in Startup.cs
d) By using JavaScript interop
Answer: a) By defining parameters in the @page directive and accessing them via RouteData
What does the OnParametersSetAsync lifecycle method do?
a) Initializes component state asynchronously
b) Handles parameter changes asynchronously
c) Updates the UI after rendering
d) Configures routing
Answer: b) Handles parameter changes asynchronously