.net 在Singleton中使用作用域服务可以吗？

将作用域的

IServiceProvider

传递给单例可以吗

上下文是我有一个单例

IMedialLibraryObservable

，它有一个内部观察者列表。这是为了触发钩子，比如OnAdding、OnDeleting等

观察者是可以实现他们想要的并重用已注册服务的接口。为了让他们能够访问所需的内容，作为方法的一部分传递了一个作用域

IServiceProvider

代码如下：

启动注册：

services.AddSingleton<IMediaLibraryObservable<MediaEventInfo>, MediaLibraryObservable>();

public interface IMediaLibraryObservable
{
    Task OnAdding(IServiceProvider _serviceProvider, MediaEventInfo info);
    ...

public async Task OnAdding(IServiceProvider _serviceProvider, MediaEventInfo info)
        {
            foreach (var observer in observers)
                await observer.OnAdding(_serviceProvider, info);
        }

public async Task OnAdding(IServiceProvider _serviceProvider, MediaEventInfo info)
        {
            using (var ms = new MemoryStream())
            {
                await info.File.CopyToAsync(ms);
                var path = await ServiceProviderHelpers.GetService<IBlobStorage>(_serviceProvider).WriteAsync(info.ContentItem.InternalName, ms);

private readonly IMediaLibraryObservable _mediaLibraryObservable;
private readonly IServiceProvider _serviceProvider;

public MediaLibraryService(IMediaLibraryObservable mediaLibraryObservable, IServiceProvider serviceProvider) {
  _mediaLibraryObservable = mediaLibraryObservable;
  _serviceProvider = serviceProvider;
}

public async Task < bool > UploadBlob(string fullPath, FormFileDto file) {
  ...
  await _mediaLibraryObservable.OnAdding(_serviceProvider, info);
  ...
}

OnAdding的实现：

services.AddSingleton<IMediaLibraryObservable<MediaEventInfo>, MediaLibraryObservable>();

public interface IMediaLibraryObservable
{
    Task OnAdding(IServiceProvider _serviceProvider, MediaEventInfo info);
    ...

public async Task OnAdding(IServiceProvider _serviceProvider, MediaEventInfo info)
        {
            foreach (var observer in observers)
                await observer.OnAdding(_serviceProvider, info);
        }

public async Task OnAdding(IServiceProvider _serviceProvider, MediaEventInfo info)
        {
            using (var ms = new MemoryStream())
            {
                await info.File.CopyToAsync(ms);
                var path = await ServiceProviderHelpers.GetService<IBlobStorage>(_serviceProvider).WriteAsync(info.ContentItem.InternalName, ms);

private readonly IMediaLibraryObservable _mediaLibraryObservable;
private readonly IServiceProvider _serviceProvider;

public MediaLibraryService(IMediaLibraryObservable mediaLibraryObservable, IServiceProvider serviceProvider) {
  _mediaLibraryObservable = mediaLibraryObservable;
  _serviceProvider = serviceProvider;
}

public async Task < bool > UploadBlob(string fullPath, FormFileDto file) {
  ...
  await _mediaLibraryObservable.OnAdding(_serviceProvider, info);
  ...
}

观察者实现：

services.AddSingleton<IMediaLibraryObservable<MediaEventInfo>, MediaLibraryObservable>();

public interface IMediaLibraryObservable
{
    Task OnAdding(IServiceProvider _serviceProvider, MediaEventInfo info);
    ...

public async Task OnAdding(IServiceProvider _serviceProvider, MediaEventInfo info)
        {
            foreach (var observer in observers)
                await observer.OnAdding(_serviceProvider, info);
        }

public async Task OnAdding(IServiceProvider _serviceProvider, MediaEventInfo info)
        {
            using (var ms = new MemoryStream())
            {
                await info.File.CopyToAsync(ms);
                var path = await ServiceProviderHelpers.GetService<IBlobStorage>(_serviceProvider).WriteAsync(info.ContentItem.InternalName, ms);

private readonly IMediaLibraryObservable _mediaLibraryObservable;
private readonly IServiceProvider _serviceProvider;

public MediaLibraryService(IMediaLibraryObservable mediaLibraryObservable, IServiceProvider serviceProvider) {
  _mediaLibraryObservable = mediaLibraryObservable;
  _serviceProvider = serviceProvider;
}

public async Task < bool > UploadBlob(string fullPath, FormFileDto file) {
  ...
  await _mediaLibraryObservable.OnAdding(_serviceProvider, info);
  ...
}

添加上的公共异步任务（IServiceProvider\u serviceProvider，MediaEventInfo） { 使用（var ms=new MemoryStream（）） { wait info.File.CopyToAsync（ms）； var path=await ServiceProviderHelpers.GetService（_serviceProvider）.WriteAsync（info.ContentItem.InternalName，ms）； 可观察的触发器（其中范围IServiceProvider被传递到单例可观察）：

services.AddSingleton<IMediaLibraryObservable<MediaEventInfo>, MediaLibraryObservable>();

public interface IMediaLibraryObservable
{
    Task OnAdding(IServiceProvider _serviceProvider, MediaEventInfo info);
    ...

public async Task OnAdding(IServiceProvider _serviceProvider, MediaEventInfo info)
        {
            foreach (var observer in observers)
                await observer.OnAdding(_serviceProvider, info);
        }

public async Task OnAdding(IServiceProvider _serviceProvider, MediaEventInfo info)
        {
            using (var ms = new MemoryStream())
            {
                await info.File.CopyToAsync(ms);
                var path = await ServiceProviderHelpers.GetService<IBlobStorage>(_serviceProvider).WriteAsync(info.ContentItem.InternalName, ms);

private readonly IMediaLibraryObservable _mediaLibraryObservable;
private readonly IServiceProvider _serviceProvider;

public MediaLibraryService(IMediaLibraryObservable mediaLibraryObservable, IServiceProvider serviceProvider) {
  _mediaLibraryObservable = mediaLibraryObservable;
  _serviceProvider = serviceProvider;
}

public async Task < bool > UploadBlob(string fullPath, FormFileDto file) {
  ...
  await _mediaLibraryObservable.OnAdding(_serviceProvider, info);
  ...
}

私有只读IMedialLibraryObservable\u mediaLibraryObservable；
私有只读服务器ViceProvider\u服务提供商；
公共媒体库服务（IMedialLibraryObservable媒体库Observable，iSeries虚拟Provider服务提供商）{
_mediaLibraryObservable=mediaLibraryObservable；
_服务提供者=服务提供者；
}
公共异步任务UploadBlob（字符串完整路径，FormFileDto文件）{
...
wait mediaLibraryObservable.OnAdding（serviceProvider，info）；
...
}

在Singleton中使用作用域服务是可以的，只要您不在Singleton中存储该作用域服务，因为这会导致出现错误。谢谢Steven，链接也很棒！