سوالات مبتدی مصاحبه Blazor

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Basics of Blazor:
What is Blazor?
Blazor is a web framework by Microsoft that allows developers to build interactive web applications using C# and .NET instead of JavaScript.

Explain the hosting models of Blazor.
Blazor supports two hosting models: Blazor WebAssembly (Wasm) and Blazor Server. WebAssembly runs in the browser, while Server runs on the server and uses SignalR for communication.

What is Razor syntax?
Razor syntax is a mix of HTML and C# used in Blazor views to define dynamic content and execute C# code.

How does Blazor handle communication between client and server in Blazor Server?
Blazor Server uses SignalR for real-time communication between the client and server.

Explain the purpose of @code block in a Blazor component.
The @code block is used for defining the C# code associated with a Blazor component. It includes fields, properties, and methods.

Components and Data Binding:
What is a Blazor component?
A Blazor component is a self-contained unit that encapsulates both the UI and the logic for a specific part of a web application.

Explain the difference between a stateful and stateless component in Blazor.
A stateful component maintains its state during the lifetime of the application, while a stateless component doesn't maintain any state and relies on parameters.

What is two-way data binding in Blazor?
Two-way data binding allows automatic synchronization of data between the UI and the underlying data model.

How can you pass parameters to a Blazor component?
Parameters can be passed to a Blazor component using attributes on the component tag.

Explain the purpose of the @inject directive in Blazor.
The @inject directive is used to inject services or dependencies into a Blazor component.

Routing and Navigation:
How do you enable routing in a Blazor application?
Routing in Blazor is enabled by adding the @page directive to a component and configuring routes in the Startup.cs file.

What is the purpose of the <RouteView> component in Blazor?
<RouteView> is used for rendering the component associated with the current route.

How can you navigate to a different page in Blazor?
Navigation in Blazor is typically done using the NavigationManager service, which provides methods like NavigateTo.

Explain the concept of route parameters in Blazor.
Route parameters allow passing values in the URL to a component. They are defined in the @page directive.

What is the role of the <Router> component in Blazor?
The <Router> component is responsible for coordinating the navigation and rendering of components based on the current route.

Forms and Validation:
How do you handle form submissions in Blazor?
Form submissions in Blazor are handled by attaching a method to the onsubmit event of the form.

What is the purpose of the EditForm component in Blazor?
The EditForm component simplifies form handling by providing built-in support for form validation and submission.

Explain the role of data annotations in form validation in Blazor.
Data annotations are used to apply validation rules to model properties. They are checked automatically when the form is submitted.

How can you display validation error messages in a Blazor form?
Error messages can be displayed using the <ValidationMessage> component, which is associated with a specific form field.

What is the purpose of the EditContext class in Blazor forms?
The EditContext class is used to track the state of a form and manage validation.

Dependency Injection and Services:
How is dependency injection implemented in Blazor?
Dependency injection is implemented using the @inject directive or through constructor injection in components.

Explain the concept of scoped services in Blazor.
Scoped services are created once per scope (usually per request) and are shared within that scope.

What is the difference between singleton and transient services in Blazor?
Singleton services are created once and shared throughout the application, while transient services are created each time they are requested.

How can you register services in a Blazor application?
Services are registered in the Startup.cs file using the ConfigureServices method.

What is the purpose of the @inject directive in Blazor?
The @inject directive is used to inject services or dependencies directly into Blazor components.

JavaScript Interoperability:
How can you invoke JavaScript functions from Blazor?
JavaScript functions can be invoked from Blazor using the JSRuntime service.

What is the purpose of the IJSObjectReference interface in Blazor?
IJSObjectReference is used to reference and interact with JavaScript objects in Blazor.

Explain the concept of JavaScript interop in Blazor.
JavaScript interop allows communication between C# code in Blazor and JavaScript code in the browser.

How can you pass parameters from C# to JavaScript in Blazor?
Parameters can be passed from C# to JavaScript using the InvokeAsync method of the JSRuntime service.

What is the role of the @ref directive in Blazor JavaScript interop?
The @ref directive is used to create a reference to a component or DOM element, which can be passed to JavaScript.

Lifecycle and Events:
Explain the lifecycle of a Blazor component.
The lifecycle of a Blazor component includes initialization, rendering, updating, and disposal.

What is the purpose of the OnInitialized and OnInitializedAsync lifecycle methods?
These methods are called when a component has been initialized but not yet rendered.

How do you handle events in Blazor components?
Events in Blazor components can be handled using the @onclick, @onchange, and other event handlers.

What is the OnParametersSet lifecycle method used for?
OnParametersSet is called when component parameters have been set, allowing you to perform actions based on parameter changes.

Explain the purpose of the OnAfterRender and OnAfterRenderAsync lifecycle methods.
These methods are called after a component has been rendered in the browser.

Authentication and Authorization:
How can you implement authentication in a Blazor application?
Authentication in Blazor can be implemented using authentication services and providers, such as IdentityServer or Azure AD.

Explain the role of the AuthorizeView component in Blazor.
AuthorizeView is used to conditionally render content based on the user's authorization status.

What is the purpose of the AuthenticationStateProvider in Blazor?
AuthenticationStateProvider is responsible for providing information about the user's authentication status.

How can you protect a Blazor component to require authentication?
Use the Authorize attribute on a component to specify that only authenticated users can access it.

Explain the concept of policies in Blazor authorization.
Policies define sets of requirements that users must meet to access specific resources. They are used in conjunction with the AuthorizeView component.

Error Handling:
How do you handle errors in a Blazor application?
Errors can be handled using try-catch blocks in C# code, and global error handling can be implemented using the ErrorBoundary component.

Explain the purpose of the ErrorBoundary component in Blazor.
ErrorBoundary is used to catch JavaScript and rendering errors within its child components and display a fallback UI.

What is the OnError event used for in Blazor?
The OnError event is triggered when an unhandled exception occurs during rendering.

How can you log errors in a Blazor application?
Errors can be logged using the built-in logging infrastructure in Blazor, which includes services like ILogger.

Explain the role of the IErrorBoundary interface in Blazor error handling.
IErrorBoundary allows custom error handling logic to be implemented in Blazor components.

Component Communication:
How can you achieve parent-to-child component communication in Blazor?
Parent-to-child communication is typically done by passing parameters from the parent to the child component.

Explain the purpose of the EventCallback in Blazor.
EventCallback is used to pass events from child to parent components in Blazor.

How can you achieve sibling component communication in Blazor?
Sibling communication often involves using a common parent component to manage state and pass data between siblings.

What is the purpose of the CascadingValue component in Blazor?
CascadingValue is used to pass a value down the component hierarchy without the need for explicit parameter passing.

Explain the concept of component references in Blazor.
Component references are used to obtain references to other components, allowing for direct communication between components.

Testing in Blazor:
How can you unit test a Blazor component?
Blazor components can be unit tested using testing libraries such as MSTest, xUnit, or NUnit.

What is the purpose of the TestHost class in Blazor testing?
TestHost is used to host a Blazor component within a test environment, facilitating unit testing.

Explain the role of the RenderComponent method in Blazor testing.
RenderComponent is used to render a Blazor component within a test, allowing for interaction and assertion.

How can you mock services in a Blazor unit test?
Services can be mocked using various mocking frameworks, such as Moq, to isolate components for testing.

What is the purpose of the TestRenderer class in Blazor testing?
TestRenderer is used to interact with and retrieve information from rendered components during testing.

Server-Side Blazor:
What are the advantages of using Server-Side Blazor?
Server-Side Blazor provides real-time updates, reduced client-side resources, and better security by keeping code on the server.

How does Server-Side Blazor handle UI updates?
UI updates in Server-Side Blazor are handled automatically by SignalR, which pushes changes from the server to the client.

Explain the role of the CircuitHandler in Server-Side Blazor.
CircuitHandler is used to customize the handling of the circuit, including connection and disconnection events.

What is the purpose of the _Imports.razor file in Server-Side Blazor?
The _Imports.razor file is used to define global using statements that apply to all components in a Server-Side Blazor application.

How can you optimize performance in Server-Side Blazor applications?
Performance optimization in Server-Side Blazor involves minimizing unnecessary component updates, reducing data transfer between client and server, and implementing caching strategies.

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