.Net Core在类库中使用当前HttpContext

HttpContext.Current在ASP.NET Core中不再存在，但是IHttpContextAccessor可以在依赖关系中注入一个新的并用于检索当前HttpContext

使用方法如下：

public class MyComponent : IMyComponent
{
    private readonly IHttpContextAccessor _contextAccessor;

    public MyComponent(IHttpContextAccessor contextAccessor)
    {
        _contextAccessor = contextAccessor;
    }

    public string GetDataFromSession()
    {
        return _contextAccessor.HttpContext.Session.GetString(*KEY*);
    }
}