C# 在.NET Core WebApp中构建服务层。我不工作了

我想在我的.NET核心WebApp中实现一个服务层，但我在构造函数依赖项注入方面有一些问题，不知道我做错了什么。也许有人能告诉我我的错误

关于服务的想法是，它们持有业务逻辑，并且是唯一与存储库对话的服务。由于每个服务都有自己的责任，因此他们不仅要与存储库对话，还要与其他服务对话，这取决于必须完成的业务任务

为此，我首先注册存储库，如下所示：

    var serviceProvider = services.BuildServiceProvider();
    services.AddScoped<IDeviceService>(r => new DeviceService(
        serviceProvider.GetService<IDeviceRepository>(),
        serviceProvider.GetService<IMasterDataRepository>(),
        ));

    services.AddScoped<IHardwareDataService>(r => new HardwareDataService(
        serviceProvider.GetService<IDeviceService>(),
        serviceProvider.GetService<IHardwareDataRepository>()
        ));
    ...
}

Startup.cs

public void ConfigureServices(IServiceCollection services) {
    this.storageConnectionString = "Server=.;Initial Catalog=MyDatabase;Integrated Security=True;";
    services.AddScoped<IDeviceRepository>(r => new EntityDeviceRepository(this.storageConnectionString));
    services.AddScoped<IMasterDataRepository>(r => new EntityMasterDataRepository(this.storageConnectionString));
    ...

public interface IHardwareDataService
{
    Task<Boolean> UpdateHardwareData(HardwareData hardwareData);
}

public class HardwareDataService : BaseService, IHardwareDataService
{
    private IDeviceService deviceService;
    private IHardwareDataRepository hardwareDataRepository;

    public HardwareDataService(IDeviceService deviceService, IHardwareDataRepository hardwareDataRepository)
    {
        this.deviceService = deviceService;
        this.hardwareDataRepository = hardwareDataRepository;
    }

    public async Task<Boolean> UpdateHardwareData(HardwareData hardwareData)
    {
        // Create the Device via the Device Service if not already existing (Business Logic)
        // Update Hardware Data of Device (Business Logic + direct Access via HWDataRepository)
    }
}

public void配置服务（IServiceCollection服务）{
this.storageConnectionString=“Server=；Initial Catalog=MyDatabase；Integrated Security=True；”；
services.AddScoped（r=>newEntityDevicePository（this.storageConnectionString））；
addScope（r=>newEntityMasterDataRepository（this.storageConnectionString））；
...

（在相同的文件和函数中）我注册我的服务如下：

    var serviceProvider = services.BuildServiceProvider();
    services.AddScoped<IDeviceService>(r => new DeviceService(
        serviceProvider.GetService<IDeviceRepository>(),
        serviceProvider.GetService<IMasterDataRepository>(),
        ));

    services.AddScoped<IHardwareDataService>(r => new HardwareDataService(
        serviceProvider.GetService<IDeviceService>(),
        serviceProvider.GetService<IHardwareDataRepository>()
        ));
    ...
}

var serviceProvider=services.BuildServiceProvider（）；
AddScoped（r=>new DeviceService(
serviceProvider.GetService（），
serviceProvider.GetService（），
));
AddScoped（r=>新的硬件数据服务(
serviceProvider.GetService（），
serviceProvider.GetService（）
));
...
}

IHardwareDataService.cs

public void ConfigureServices(IServiceCollection services) {
    this.storageConnectionString = "Server=.;Initial Catalog=MyDatabase;Integrated Security=True;";
    services.AddScoped<IDeviceRepository>(r => new EntityDeviceRepository(this.storageConnectionString));
    services.AddScoped<IMasterDataRepository>(r => new EntityMasterDataRepository(this.storageConnectionString));
    ...

public interface IHardwareDataService
{
    Task<Boolean> UpdateHardwareData(HardwareData hardwareData);
}

public class HardwareDataService : BaseService, IHardwareDataService
{
    private IDeviceService deviceService;
    private IHardwareDataRepository hardwareDataRepository;

    public HardwareDataService(IDeviceService deviceService, IHardwareDataRepository hardwareDataRepository)
    {
        this.deviceService = deviceService;
        this.hardwareDataRepository = hardwareDataRepository;
    }

    public async Task<Boolean> UpdateHardwareData(HardwareData hardwareData)
    {
        // Create the Device via the Device Service if not already existing (Business Logic)
        // Update Hardware Data of Device (Business Logic + direct Access via HWDataRepository)
    }
}

公共接口IHardwareDataService
{
任务更新硬件数据（硬件数据硬件数据）；
}

HardwareDataService.cs

public void ConfigureServices(IServiceCollection services) {
    this.storageConnectionString = "Server=.;Initial Catalog=MyDatabase;Integrated Security=True;";
    services.AddScoped<IDeviceRepository>(r => new EntityDeviceRepository(this.storageConnectionString));
    services.AddScoped<IMasterDataRepository>(r => new EntityMasterDataRepository(this.storageConnectionString));
    ...

public interface IHardwareDataService
{
    Task<Boolean> UpdateHardwareData(HardwareData hardwareData);
}

public class HardwareDataService : BaseService, IHardwareDataService
{
    private IDeviceService deviceService;
    private IHardwareDataRepository hardwareDataRepository;

    public HardwareDataService(IDeviceService deviceService, IHardwareDataRepository hardwareDataRepository)
    {
        this.deviceService = deviceService;
        this.hardwareDataRepository = hardwareDataRepository;
    }

    public async Task<Boolean> UpdateHardwareData(HardwareData hardwareData)
    {
        // Create the Device via the Device Service if not already existing (Business Logic)
        // Update Hardware Data of Device (Business Logic + direct Access via HWDataRepository)
    }
}

公共类硬件数据服务：BaseService、IHardwareDataService
{
私人idevice服务设备服务；
私有iHardware数据仓库硬件数据仓库；
公共硬件存储服务（IDeviceService deviceService，i硬件存储硬件存储）
{
this.deviceService=设备服务；
this.hardwareDataRepository=hardwareDataRepository；
}
公共异步任务更新硬件数据（硬件数据硬件数据）
{
//如果尚未存在，则通过设备服务创建设备（业务逻辑）
//更新设备的硬件数据（业务逻辑+通过HWDataRepository直接访问）
}
}

问题

“

IDeviceService

”工作正常。 “

IHardwareDataService

”不可用。确切地说，对象“

IDeviceService

”是

null

似乎我不能通过构造函数依赖项注入将一个服务提供给另一个服务，但我不明白为什么以及如何以正确的方式提供服务

---

关于如何解决此问题的任何提示？

在这种情况下，确实不需要构建提供程序

查看您注册服务的方式，可以简化为

services.AddScoped<IDeviceService, DeviceService>();
services.AddScoped<IHardwareDataService, HardwareDataService>();

services.addScope（）；
services.addScope（）；

在解析实现时，框架将注入必要的依赖项

参考资料：

尝试更换

 var serviceProvider = services.BuildServiceProvider();
    services.AddScoped<IDeviceService>(r => new DeviceService(
        serviceProvider.GetService<IDeviceRepository>(),
        serviceProvider.GetService<IMasterDataRepository>(),
        ));

    services.AddScoped<IHardwareDataService>(r => new HardwareDataService(
        serviceProvider.GetService<IDeviceService>(),
        serviceProvider.GetService<IHardwareDataRepository>()
        ));

var serviceProvider=services.BuildServiceProvider（）；
AddScoped（r=>new DeviceService(
serviceProvider.GetService（），
serviceProvider.GetService（），
));
AddScoped（r=>新的硬件数据服务(
serviceProvider.GetService（），
serviceProvider.GetService（）
));

到

services.addScope（）；
services.addScope（）；

现在很有魅力。谢谢你的帮助。我会仔细查看你提供的链接，因为我不能100%确定为什么它现在能正常工作。