尝试激活“”时无法解析类型“”的服务

Question

我正在 Core 2.0 上创建一个项目，但从过去 2 天开始，我一直在依赖注入。以下是我的代码-

public void ConfigureServices(IServiceCollection services)
{
    services.AddMvc();
    services.AddTransient<IAccountBAL, AccountBAL>();
}

public interface IAccountBAL
{
    Task CreateSuperAdmin();
}

public class AccountBAL:IAccountBAL
{
    private ApplicationDbContext _connection;
    private readonly RoleManager<IdentityRole> _roleManager;
    private readonly SignInManager<ApplicationUser> _signInManager;
    private readonly UserManager<ApplicationUser> _userManager;
    public AccountBAL(ApplicationDbContext connection, RoleManager<IdentityRole> roleManager, SignInManager<ApplicationUser> signInManager, UserManager<ApplicationUser> userManager)
    {
        _connection = connection;
        _roleManager = roleManager;
        _signInManager = signInManager;
        _userManager = userManager; 
    }
    public async Task CreateSuperAdmin()
    {
        //My Code  
    }
}

但是当我运行我的项目时，我收到错误在尝试激活“UserAuth.BAL.AccountBAL”时无法解析类型“DALUser.Data.ApplicationDbContext”的服务。 但是，当我从以下代码中删除 IAccountBAL _iAccountBAL 时，它可以工作。但是我需要传递这种依赖关系。

public void Configure(IApplicationBuilder app, IHostingEnvironment env, IAccountBAL _iAccountBAL)
{

}

Answer 1

在您的Startup 课程中，您需要像这样注册您的DbContext：

public void ConfigureServices(IServiceCollection services)
{
    // ... 
    services.AddDbContext<ApplicationDbContext>(options =>
    {
        options.UseSqlServer(Configuration.GetConnectionString("DefaultConnection"));
    });
    // ...
}

这里是example of registering custom Identity based DbContext。