没加 await 调用 async 方法遇到问题："Cannot access a disposed object. Object name: 'IServiceProvider'"
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悬赏园豆：30
[已解决问题]
解决于 2022-11-29 23:00
异步方法所在的类的构造函数注入了 IServiceProvider，通过它解析实例
var db = _serviceProvider.GetRequiredService(); 运行时报错
System.ObjectDisposedException: Cannot access a disposed object.
Object name: 'IServiceProvider'.
at Microsoft.Extensions.DependencyInjection.ServiceLookup.ThrowHelper.ThrowObjectDisposedException()
at Microsoft.Extensions.DependencyInjection.ServiceLookup.ServiceProviderEngineScope.GetService(Type serviceType)
at Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetRequiredService(IServiceProvider provider, Type serviceType)
at Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetRequiredService[T](IServiceProvider provider)
at Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.CreateAsyncScope(IServiceProvider provider)
最佳答案
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参考 Multi-Threaded Entity Framework Core Samples，用 IServiceScopeFactory 解决了问题。
构造函数注入 IServiceScopeFactory，然后
await using var scoped = _scopeFactory.CreateAsyncScope();
var sp = scoped.ServiceProvider;
var db = sp.GetRequiredService<BlogDbContext>();
stackoverflow 上发现一个参考：.NET Core IServiceScopeFactory.CreateScope() vs IServiceProvider.CreateScope() extension
