Mode:
Duration:
1
Coding works best on desktop or with an external keyboard.
Blazor Component with Event Callback - Blazor-wasm Typing CST Test
Blazor Component with Event Callback — Blazor-wasm Code
A parent and child component demonstrating event callbacks.
# blazor/demo/EventCallback.razor
<ChildComponent OnNotify="HandleNotification" />
<p>@message</p>
@code {
private string message = "Waiting for notification...";
private void HandleNotification(string msg) {
message = msg;
}
}
// ChildComponent.razor
<button @onclick="NotifyParent">Notify Parent</button>
@code {
[Parameter] public EventCallback<string> OnNotify { get; set; }
private async Task NotifyParent() {
await OnNotify.InvokeAsync("Notification received!");
}
}Blazor-wasm Language Guide
Blazor WebAssembly (WASM) is a client-side web framework from Microsoft that allows developers to build interactive web applications using C# and .NET instead of JavaScript. Applications run directly in the browser via WebAssembly.
Primary Use Cases
- ▸Interactive single-page applications (SPAs) with C#
- ▸Line-of-business applications requiring .NET libraries
- ▸Client-side applications with offline capabilities
- ▸Web apps needing tight integration with ASP.NET Core backends
- ▸Modern web UI replacement for WinForms/WPF apps
Notable Features
- ▸Client-side execution using WebAssembly
- ▸Component-based UI architecture
- ▸Full access to .NET runtime libraries in the browser
- ▸Integration with ASP.NET Core for API calls and authentication
- ▸Support for dependency injection and routing
Origin & Creator
Blazor was developed by Microsoft, first introduced in 2018, with WebAssembly support added to enable fully client-side .NET applications.
Industrial Note
Blazor WASM is ideal for enterprises and developers invested in the Microsoft ecosystem who want C# web development without relying on JavaScript frameworks.
Quick Explain
- ▸Blazor WASM enables full-stack C# development, running .NET code in the browser.
- ▸Uses WebAssembly to compile .NET IL (Intermediate Language) into a binary format that browsers can execute.
- ▸Supports component-based architecture, enabling reusable UI elements.
- ▸Integrates seamlessly with .NET ecosystem, including libraries, dependency injection, and tooling.
- ▸Runs entirely client-side, reducing server load and enabling offline capabilities.
Core Features
- ▸Razor components for UI development
- ▸Two-way data binding
- ▸Event handling in C# instead of JavaScript
- ▸JavaScript interop for accessing browser APIs
- ▸Lazy loading and modular assemblies to reduce payload
Learning Path
- ▸Learn C# and .NET fundamentals
- ▸Understand Razor syntax and components
- ▸Explore Blazor component lifecycle
- ▸Integrate with ASP.NET Core backend
- ▸Build sample SPA applications
Practical Examples
- ▸To-do application with local storage
- ▸Client-side dashboard with charts and API integration
- ▸Form-based enterprise application
- ▸Offline-capable PWA
- ▸Interactive data visualization with Blazor components
Comparisons
- ▸Blazor WASM vs React: Blazor uses C#, React uses JS/TS
- ▸Blazor WASM vs Angular: Blazor SPA runs in .NET runtime, Angular compiles to JS
- ▸Blazor WASM vs Vue.js: Blazor integrates with .NET ecosystem natively
- ▸Blazor WASM vs Blazor Server: WASM runs client-side, Server runs on backend
- ▸Blazor WASM vs JS frameworks: Strong typing and tooling with C#
Strengths
- ▸Leverages existing .NET skills and libraries
- ▸C# code runs natively in the browser via WebAssembly
- ▸Component reuse between server-side and client-side Blazor
- ▸Strong Microsoft tooling support (Visual Studio, CLI, debugging)
- ▸Secure execution sandboxed in the browser
Limitations
- ▸Initial download size can be large compared to JS frameworks
- ▸Browser compatibility depends on WebAssembly support (modern browsers only)
- ▸SEO is challenging without prerendering
- ▸Limited ecosystem compared to JavaScript frameworks
- ▸Client-side execution may not be ideal for CPU-intensive tasks
When NOT to Use
- ▸Applications needing SEO without prerendering
- ▸Very large-scale SPAs requiring minimal payload
- ▸Browsers without WebAssembly support
- ▸CPU-intensive client-side computations
- ▸Projects without .NET developer expertise
Cheat Sheet
- ▸dotnet new blazorwasm - create a new Blazor WASM project
- ▸dotnet run - run project locally
- ▸@code { } - define component logic in Razor file
- ▸@inject - inject service into component
- ▸NavigationManager.NavigateTo() - programmatic navigation
FAQ
- ▸Is Blazor WASM free?
- ▸Yes - open-source as part of .NET runtime.
- ▸Does Blazor run on all browsers?
- ▸Modern browsers with WebAssembly support are required.
- ▸Can I use existing .NET libraries?
- ▸Yes - compatible libraries can run in WASM.
- ▸How is authentication handled?
- ▸Via ASP.NET Core Identity, JWT, or external providers.
- ▸Can Blazor WASM work offline?
- ▸Yes - using PWA caching and local storage.
30-Day Skill Plan
- ▸Week 1: C# and .NET basics
- ▸Week 2: Razor components and data binding
- ▸Week 3: API integration and DI
- ▸Week 4: JavaScript interop and advanced components
- ▸Week 5: PWA features and deployment optimization
Final Summary
- ▸Blazor WASM enables client-side web apps using C# and .NET.
- ▸Runs in the browser via WebAssembly with full .NET support.
- ▸Component-based architecture allows reusable UI blocks.
- ▸Integrates with ASP.NET Core for API, auth, and backend services.
- ▸Ideal for .NET developers building SPAs without JavaScript.
Project Structure
- ▸wwwroot/ - static assets (JS, CSS, images)
- ▸Pages/ - Razor components mapped to routes
- ▸Shared/ - reusable components and layouts
- ▸Program.cs - application entry point and DI configuration
- ▸_Imports.razor - global using directives
- ▸App.razor - root component defining router and layout
Monetization
- ▸Enterprise applications as SaaS
- ▸Internal line-of-business tools
- ▸Progressive web apps for clients
- ▸Interactive dashboards and analytics portals
- ▸Cross-platform web applications replacing desktop clients
Productivity Tips
- ▸Reuse components across projects
- ▸Use dependency injection for shared services
- ▸Leverage existing .NET libraries
- ▸Optimize lazy loading and bundling
- ▸Use Visual Studio/VS Code productivity extensions
Basic Concepts
- ▸Razor Component - UI element written in C# and Razor syntax
- ▸Binding - two-way connection between UI and data model
- ▸Event Callback - handles user interactions in C#
- ▸Dependency Injection - inject services into components
- ▸Routing - navigate between components in SPA
More Blazor-wasm Typing Exercises
Simple Blazor WebAssembly ComponentBlazor Component with Button ClickBlazor Component with Two-Way BindingBlazor Component with Conditional RenderingBlazor Component with LoopBlazor Component with Cascading ParameterBlazor Component with TimerBlazor Component with Form ValidationBlazor Component with Nested Components