c# 批量注入示例代码

using Microsoft.Extensions.DependencyInjection;
using System;
using System.Linq;
using System.Reflection;

// 自定义属性来标记服务类型
[AttributeUsage(AttributeTargets.Class, AllowMultiple = false, Inherited = false)]
public class ServiceTypeAttribute : Attribute
{
    public ServiceLifetime Lifetime { get; }

    public ServiceTypeAttribute(ServiceLifetime lifetime)
    {
        Lifetime = lifetime;
    }
}

public static class DependencyInjectionExtensions
{
    /// <summary>
    /// 批量注册服务
    /// </summary>
    /// <param name="services">IServiceCollection</param>
    /// <param name="servicePrefix">服务类的前缀，例如 "Service"</param>
    /// <param name="interfacePrefix">接口的前缀，例如 "I"</param>
    public static void RegisterServices(this IServiceCollection services, string servicePrefix, string interfacePrefix)
    {
        if (services == null)
        {
            throw new ArgumentNullException(nameof(services));
        }

        // 获取当前程序集中所有类
        var types = Assembly.GetExecutingAssembly().GetTypes();

        // 筛选出符合服务命名约定的类
        var serviceTypes = types
            .Where(t => t.Name.StartsWith(servicePrefix) && !t.IsInterface && !t.IsAbstract)
            .ToList();

        // 遍历所有服务类
        foreach (var serviceType in serviceTypes)
        {
            // 尝试查找对应的接口
            var interfaceType = types.FirstOrDefault(t => t.Name == interfacePrefix + serviceType.Name.Substring(servicePrefix.Length) && t.IsInterface);

            if (interfaceType != null)
            {
                // 获取服务类型上的 ServiceTypeAttribute
                var serviceTypeAttribute = serviceType.GetCustomAttribute<ServiceTypeAttribute>();
                var lifetime = serviceTypeAttribute?.Lifetime ?? ServiceLifetime.Scoped; // 默认使用 Scoped

                // 根据不同的生命周期注册服务
                switch (lifetime)
                {
                    case ServiceLifetime.Singleton:
                        services.AddSingleton(interfaceType, serviceType);
                        break;
                    case ServiceLifetime.Scoped:
                        services.AddScoped(interfaceType, serviceType);
                        break;
                    case ServiceLifetime.Transient:
                        services.AddTransient(interfaceType, serviceType);
                        break;
                    default:
                        services.AddScoped(interfaceType, serviceType); // 默认使用 Scoped
                        break;
                }
            }
            else
            {
                // 如果没有找到对应的接口，则可以选择只注册服务本身，或者抛出异常
                // 这里选择抛出异常，提示开发者需要有对应的接口
                throw new InvalidOperationException($"Service {serviceType.Name} does not have a corresponding interface (expected interface name: {interfacePrefix}{serviceType.Name.Substring(servicePrefix.Length)})");
            }
        }
    }
}

// 示例接口和服务
public interface IUserService
{
    void DoSomething();
}

[ServiceType(ServiceLifetime.Scoped)] // 使用属性标记生命周期
public class UserService : IUserService
{
    public void DoSomething()
    {
        Console.WriteLine("UserService.DoSomething() called.");
    }
}

public interface IOrderService
{
     void ProcessOrder();
}

[ServiceType(ServiceLifetime.Transient)]
public class OrderService: IOrderService
{
    public void ProcessOrder()
    {
        Console.WriteLine("OrderService.ProcessOrder() called.");
    }
}

public class Program
{
    public static void Main(string[] args)
    {
        // 创建 ServiceCollection
        IServiceCollection services = new ServiceCollection();

        // 注册服务
        services.RegisterServices("Service", "I");

        // 添加其他必要的服务，例如 MVC
        services.AddMvc(); // 如果是 ASP.NET Core MVC 项目

        // 构建 ServiceProvider
        IServiceProvider serviceProvider = services.BuildServiceProvider();

        // 从 ServiceProvider 中获取服务并使用
        var userService = serviceProvider.GetService<IUserService>();
        userService?.DoSomething();

        var orderService = serviceProvider.GetService<IOrderService>();
        orderService?.ProcessOrder();
        Console.ReadKey();
    }
}