Validation failed for one or more entities. See EntityValidationErrors property for more details

“/”应用程序中的服务器错误。 Validation failed for one or more entities. See 'EntityValidationErrors' property for more details. 说明: 执行当前 Web 请求期间，出现未经处理的异常。请检查堆栈跟踪信息，以了解有关该错误以及代码中导致错误的出处的详细信息。 异常详细信息: System.Data.Entity.Validation.DbEntityValidationException: Validation failed for one or more entities. See 'EntityValidationErrors' property for more details. 源错误:   -------------------------------------...