Blazor

Blazor is a free, open-source web framework for building interactive client-side web UIs with .NET. Blazor allows you to build native client-side web UIs using C# and HTML. Blazor apps are single-page applications (SPAs) that can run in the browser using the WebAssembly runtime, or on the server using a .NET backend.

Key Concepts

Blazor Server: Blazor apps that run on the server and use a real-time connection (SignalR) to the browser. UI updates are handled by SignalR.
Blazor WebAssembly (WASM): Blazor apps that run entirely in the browser on a .NET runtime compiled to WebAssembly. This enables true client-side execution without a server-side connection for UI logic.
Components: Blazor apps are built using reusable UI components written in C# and Razor syntax.
Razor Syntax: A powerful templating language that combines C# code with HTML markup.
Dependency Injection: Blazor integrates seamlessly with .NET's built-in dependency injection system.

Getting Started with Blazor

To start building Blazor applications, you'll need the .NET SDK installed. You can create a new Blazor project using the .NET CLI:

dotnet new blazorwasm -o MyBlazorApp
cd MyBlazorApp
dotnet run

This will create a new Blazor WebAssembly project and start a development server.

Blazor Server vs. Blazor WebAssembly

Choosing between Blazor Server and Blazor WebAssembly depends on your application's requirements:

Blazor Server: Ideal for applications that require server-side resources, have low latency requirements, or need to leverage existing server-side logic. However, it requires a constant connection to the server.
Blazor WebAssembly: Suitable for applications that need to run offline, want to reduce server load, or desire a faster initial load time (once the WebAssembly runtime is downloaded). The initial download size can be larger.

Components and Data Binding

Blazor components are the building blocks of your UI. They are typically defined in .razor files.

Example Component

<p>Current count: @currentCount</p>

<button class="btn btn-primary" @onclick="IncrementCount">Click me</button>

@code {
    private int currentCount = 0;

    private void IncrementCount()
    {
        currentCount++;
    }
}

Note: Blazor's component model promotes reusability and maintainability. You can pass parameters to components and handle events.

Routing

Blazor supports client-side routing, allowing users to navigate between different pages within your application without full page reloads. Use the @page directive to mark a component as a routable page.

Example Routing Directive

@page "/counter"
@page "/fetchdata"

.NET Documentation