Blazor: Build Interactive Web UIs with C#
Blazor is a web framework for building interactive client-side web UIs with .NET. Blazor allows you to build modern web apps by leveraging your .NET skills and existing .NET libraries in the browser. Blazor apps run in the browser using a .NET runtime that's compiled to WebAssembly.
Key Features and Concepts
- Component-Based Architecture: Blazor uses Razor components, which are self-contained pieces of UI logic and markup.
- C# in the Browser: Write client-side UI logic entirely in C#, sharing code and libraries with your .NET backend.
- Server-Side Rendering (SSR) and Static Site Generation (SSG): Blazor supports rendering components on the server for improved initial load times and SEO.
- Client-Side Rendering (CSR) with WebAssembly: Run .NET code directly in the browser via WebAssembly.
- Hybrid Approaches: Blazor Hybrid allows you to host Blazor components in native desktop and mobile apps using .NET MAUI.
- Routing: Blazor provides a powerful routing system to navigate between components.
- Dependency Injection: Built-in support for dependency injection makes managing services easier.
- Event Handling: Easily handle browser events and user interactions.
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 runThis command creates a new Blazor WebAssembly project named "MyBlazorApp".
Core Concepts Explained
Razor Components
Razor components are the fundamental building blocks of a Blazor application. They are typically defined in .razor files and combine HTML markup with C# code.
Example: A simple counter component
@page "/counter"
Counter
Current count: @currentCount
@code {
private int currentCount = 0;
private void IncrementCount()
{
currentCount++;
}
}Data Binding
Blazor supports one-way and two-way data binding, allowing seamless synchronization between UI elements and component state.
Two-Way Data Binding
Using the @bind directive, you can easily bind an input element to a component property. Changes in the UI update the property, and changes to the property update the UI.
<input type="text" @bind="Message" />
<p>@Message</p>
@code {
public string Message { get; set; } = "Initial Value";
}Lifecycle Methods
Blazor components have a defined lifecycle, with methods like OnInitializedAsync, OnParametersSetAsync, and ShouldRender that allow you to hook into various stages of component execution.
OnInitializedAsync for asynchronous initialization logic, such as fetching data from an API.
Blazor Hosting Models
Blazor offers flexible hosting models to suit different application needs:
- Blazor Server: Components render on the server, and UI updates are sent to the client over SignalR.
- Blazor WebAssembly: Components run directly in the browser via WebAssembly.
- Blazor Hybrid: Components are hosted in native desktop or mobile apps (.NET MAUI).