出现错误-> System.Linq.Enumerable + WhereSelectListIterator`2 [Tdsb.Aris.Pims.Entity.PartnershipFunding，System.String]

Question

private string Paidby
{
    get
    {
        string paidBy = string.Empty;

        if(this.PartnershipFundingEntity!=null)
        {
            paidBy = (PartnershipFundingEntity.Where(x => x.FundingTypeId == 1).Select(y => y.CfPurposeList)).ToString();
        }
        return paidBy;
    }
}

收到类似->的错误

System.Linq.Enumerable + WhereSelectListIterator`2 [Tdsb.Aris.Pims.Entity.PartnershipFunding，System.String]

Answer 1

您的问题表明有一个错误，但该值似乎是被推送到paidBy string的类型名称：

paidBy = (PartnershipFundingEntity
   .Where(x => x.FundingTypeId == 1)          // where iterator at this point
   .Select(y => y.CfPurposeList))             // WhereSelectListIterator at this point
   .ToString();                               // ToString() returns type name by default

我想你应该有这样的东西：

paidBy = PartnershipFundingEntity
   .Where(x => x.FundingTypeId == 1)
   .First(x => <boolean condition to select one element>)
   .PaidByProp;

如果找到单个元素，则此方法有效，否则应使用FirstOrDefault并测试其为null。 我认为?. （空条件）可用于缩小到一条指令。