.Net6-利用IServiceProvider实现全局依赖注入

需求背景：自定义类库程序中的类文件引用IService接口对象并实现依赖注入。

1.修改应用程序Program.cs文件

1 var builder = WebApplication.CreateBuilder(args);
2 builder.Services.AddProgramService();
3 
4 
5 var app = builder.Build();
6 InternalApp.ServiceProvider = app.Services;

2.服务注册

 1 public  static class DIServiceExtensions
 2     {
 3         public static void AddProgramService(this IServiceCollection services)
 4         {
 5             string[] clas = new string[] { "XX.Repository", "XX.Service" };
 6             foreach (string c in clas)
 7             {
 8                 Register(services, c);
 9             }
10         }
11 
12         private static void Register(IServiceCollection services,string item)
13         {
14             Assembly assembly = Assembly.Load(item);
15             foreach(var type in assembly.GetTypes())
16             {
17                 var serviceAttribute = type.GetCustomAttribute<AppServiceAttribute>();
18 
19                 if(serviceAttribute != null)
20                 {
21                     var serviceType = serviceAttribute.ServiceType;
22                     if(serviceType == null && serviceAttribute.InterfaceServiceType)
23                     {
24                         serviceType = type.GetInterfaces().FirstOrDefault();
25                     }
26                     if(serviceType == null)
27                     {
28                         serviceType = type;
29                     }
30 
31                     switch(serviceAttribute.ServiceLifetime)
32                     {
33                         case LifeTime.Singleton:
34                             services.AddSingleton(serviceType,type);
35                             break;
36                         case LifeTime.Scoped:
37                             services.AddScoped(serviceType, type);
38                             break;
39                         case LifeTime.Transient:
40                             services.AddTransient(serviceType, type);
41                             break;
42                         default:
43                             services.AddTransient(serviceType, type);
44                             break;
45                     }
46 
47                     System.Console.WriteLine($"注册：{serviceType}");
48                 }
49             }
50         }
51     }

3. 新建InternalApp类文件

1     public static class InternalApp
2     {
3         /// <summary>
4         /// 应用服务
5         /// </summary>
6         public static IServiceProvider ServiceProvider;
7     }

4. 新建GlobalContext.cs文件

 1 public static class GlobalContext
 2  {
 3         /// <summary>
 4         /// 服务提供器
 5         /// </summary>
 6         public static IServiceProvider ServiceProvider => InternalApp.ServiceProvider;
 7 
 8         /// <summary>
 9         /// 获取请求生命周期的服务
10         /// </summary>
11         /// <param name="type"></param>
12         /// <returns></returns>
13         public static object GetService(Type type)
14         {
15             return ServiceProvider.GetService(type);
16         }
17 
18         public static TService GetService<TService>() where TService : class
19         {
20             return GetService(typeof(TService)) as TService;
21         }
22  }

5. 类文件调用服务对象

1 public class A
2 {
3      private readonly IAService _AService = GlobalContext.GetService<IAService>();
4 }