ASP.NET CreateBuilder
last modified April 3, 2025
In this article, we explore the WebApplication.CreateBuilder method in ASP.NET 8. This method is fundamental for configuring and launching ASP.NET applications.
ASP.NET is a cross-platform, high-performance framework for building modern web applications. CreateBuilder simplifies application configuration and startup.
Basic Definition
WebApplication.CreateBuilder is a factory method that creates a WebApplicationBuilder instance. This builder pattern is the modern way to configure ASP.NET apps.
The builder provides access to configuration, services, logging, and hosting settings. It replaces the traditional Startup class in ASP.NET Core.
CreateBuilder sets up sensible defaults for web apps, including Kestrel server, configuration sources, and logging. It's the entry point for most ASP.NET apps.
ASP.NET CreateBuilder Example
The following example demonstrates a basic ASP.NET application using CreateBuilder.
var builder = WebApplication.CreateBuilder(args);
// Add services to the container.
builder.Services.AddControllers();
builder.Services.AddEndpointsApiExplorer();
builder.Services.AddSwaggerGen();
var app = builder.Build();
// Configure the HTTP request pipeline.
if (app.Environment.IsDevelopment())
{
app.UseSwagger();
app.UseSwaggerUI();
}
app.UseHttpsRedirection();
app.UseAuthorization();
app.MapControllers();
app.Run();
This code sets up a complete ASP.NET Web API application. The CreateBuilder method initializes the application with default configuration and services.
The builder.Services property is used to register services in the dependency injection container. Here we add controllers, API explorer, and Swagger.
After building the app with builder.Build(), we configure the HTTP pipeline. Middleware components are added for development tools, HTTPS, and authorization.
MapControllers enables attribute routing for controller actions. Finally, app.Run() starts the application and begins listening for requests.
This minimal API approach reduces boilerplate while providing full functionality. The entire application configuration is contained in a single file.
Source
Microsoft ASP.NET Core Fundamentals Documentation
In this article, we have explored the CreateBuilder method in ASP.NET 8. This modern approach simplifies application configuration while maintaining flexibility.
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