.NET 6 - 将服务注入 program.cs

Question

I know how to do dependency injection in the Startup.cs in .NET 5 (or before), but how do I do the same with the top-level Program.cs in .NET 6?

.NET 5: for example, I can inject a class in the Configure method

public class Startup
{
    public IConfiguration _configuration { get; }
    public IWebHostEnvironment _env { get; set; }

    public Startup(IConfiguration configuration, IWebHostEnvironment env)
    {
        _configuration = configuration;
        _env = env;
    }

    public void ConfigureServices(IServiceCollection services)
    {
        // TODO
    }

    public void Configure(IApplicationBuilder app, IWebHostEnvironment env, IToInjectService serviceToInject)
    {
        // USE SERVICE
    }
}

How can I achieve this in .NET 6?

Answer 1

您将服务添加到builder.Services集合中，然后使用

var myService = services.BuildServiceProvider().GetService<MyService>();

Answer 2

Using .Net 6 is easy. Just execute GetService method after configure app services and have ran Build method.

WebApplication? app = builder.Build();

var someService = app.Services.GetService<SomeService>();

someService.DoSomething();

Answer 3

Inside the program.cs file you can manage your services by builder.Services

For example, I added DbContext and Two different services based on the Singleton pattern and Scoped

var builder = WebApplication.CreateBuilder(args);

// Add services to the container.
builder.Services.AddDbContext<MyDbContext>(options =>
{
    // options.UseSqlServer(...);
});
builder.Services.AddSingleton<IMyService, MyService>();
builder.Services.AddScoped<IMySessionBasedService, MySessionBasedService>();

For more information check Code samples migrated to the new minimal hosting model in ASP.NET Core 6.0

Answer 4

I tried to use the GetService method but I pass the service interface type as input (as shown below) and this worked with me.

var app = builder.Build();    
var injectedService1 = app.Services.GetService<IToInjectService>();
injectedService1.DoSomething();

Answer 5

If you need to use a scoped service at start, this is how your program.cs should looks like:

var builder = WebApplication.CreateBuilder(args);

//Add the service
builder.Services.AddScoped<IMyDependency, MyDependency>();

var app = builder.Build();

using (var serviceScope = app.Services.CreateScope())
{
    var services = serviceScope.ServiceProvider;

    var myDependency = services.GetRequiredService<IMyDependency>();

    //Use the service
    myDependency.DoSomething();

}

app.Run();

from: Resolve a service at app start up

it did work for mi DbInitializer