调用异步方法前
HttpContext context = System.Web.HttpContext.Current;
HttpRuntime.Cache.Insert("context", context);
异步方法里
HttpContext context = HttpContext.Current;
if (context == null)
{
context = HttpRuntime.Cache.Get("context") as HttpContext;
}
摘自:https://blog.csdn.net/chenjian88886666/article/details/82959252