ASP.NET-Core-5-IoC

IoC implementations in ASP.NET Core 5

About this code

This sample shows you how to use IoC in your ASP.NET Core programs.

The target of this sample is to show you how singleton, transient and scoped work in the typical Web Api app.

I try to show you the lifetime, use and reuse of a Log object inside of the Web Api too.

You will have to change the type of object that you want to use, in the Startup.cs file to see the different behaviours.

To use singleton, your code will look as:

public void ConfigureServices(IServiceCollection services)
{
    // Singleton
    services.AddSingleton<ILog, FakeLog>();

    // Transient
    //services.AddTransient<ILog, FakeLog>();

    // Scoped
    //services.AddScoped<ILog, FakeLog>();

    services.AddControllers();

    services.AddSwaggerGen(c =>
    {
        c.SwaggerDoc("v1", new OpenApiInfo { Title = "WebApp", Version = "v1" });
    });
}

To use transient:

public void ConfigureServices(IServiceCollection services)
{
    // Singleton
    //services.AddSingleton<ILog, FakeLog>();

    // Transient
    //services.AddTransient<ILog, FakeLog>();

    // Scoped
    services.AddScoped<ILog, FakeLog>();

    services.AddControllers();

    services.AddSwaggerGen(c =>
    {
        c.SwaggerDoc("v1", new OpenApiInfo { Title = "WebApp", Version = "v1" });
    });
}

To use scoped:

public void ConfigureServices(IServiceCollection services)
{
    // Singleton
    //services.AddSingleton<ILog, FakeLog>();

    // Transient
    //services.AddTransient<ILog, FakeLog>();

    // Scoped
    services.AddScoped<ILog, FakeLog>();

    services.AddControllers();

    services.AddSwaggerGen(c =>
    {
        c.SwaggerDoc("v1", new OpenApiInfo { Title = "WebApp", Version = "v1" });
    });
}

The FakeLog.cs file that is used, write a message in the Output window of Visual Studio too, to know if the object has been disposed or not.

For more information about dependency injection in ASP.NET Core, please read this information