如何在泛型类型中注册依赖项注入? (.net核心) [英] How to register dependency injection with generic types? (.net core)

问题描述

我有一个asp.net核心网络应用，在appSettings.json文件中有多个参数.

I have an asp.net core web app with multiple parameters in appSettings.json file.

我不想在构造函数中使用IOptions<MyObject>的服务.

I didnt' want to have services having IOptions<MyObject> in the constructor.

我想要构造函数中的MyObject. 所以我找到了以下文章:

I wanted MyObject in the constructor. So I found the following article: https://weblog.west-wind.com/posts/2017/dec/12/easy-configuration-binding-in-aspnet-core-revisited which is very interesting.

但是我想走得更远.我想创建一个扩展方法来生成注入.

But I want to go further. I would like to create an extension method to generate the injection.

这就是我想做的:

using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;

namespace Common.WebTools.Extensions
{
    public static class IServiceCollectionExtensions
    {
        public static IServiceCollection AddSingletonConfigurationObject<T>(this IServiceCollection services, 
            IConfiguration configuration,
            string appSettingsKey) where T:new()
        {   
            var obj2 = new T();
            configuration.Bind(appSettingsKey, obj);
            services.AddSingleton(obj2); //compilation failed
            return services;
        }
    }
}

然后在我的ConfigureServices方法中可以调用

And then in my ConfigureServices method I can call

services.AddSingletonConfigurationObject<Common.Tools.Configuration.GoogleAnalyticsConfiguration>(Configuration, "GoogleAnalytics");

但是我在这行有一个补充错误:

But I Have a compliation error on this line:

services.AddSingleton(obj2); 

有人知道我该如何纠正错误?

Does somebody know how could I correct the error?

推荐答案

您可以使用services.AddScoped在范围请求中仅使用1个实例.因此，与AddTransient相比，总体上可以改进

You can use services.AddScoped to use only 1 instance in the scope request. So in general improvement compare to AddTransient

services.AddScoped(typeof(IGenericRepository<>), typeof(GenericRepository<>));

所以我的界面和类看起来像这样

So my interface and class will look like this

public interface IGenericRepository<T> where T : class

public class GenericRepository<T> : IGenericRepository<T> where T : class

这篇关于如何在泛型类型中注册依赖项注入? (.net核心)的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！