c# - 根据子集合总结一个属性

Question

我感觉自己像一个踢屁股比赛中的独腿男子...我需要向我的 LINQ 数据集添加一个属性，该数据集提供基于子集合属性的摘要，然后展平我的数据。 (我正在创建一个 .rdlc 数据集。)我终于想出了如何展平我的数据，但我无法弄清楚如何根据哪组审阅者提供的评估得出一个值。

我有一些评估，我需要根据审稿人所属的审稿人组总结一个结果:

1. 如果评审组中的任何评估是“大问题”，则返回“大问题”。

2. 如果所有评估都说“没问题”，则返回“没问题”。

3. 如果没有评估是“大问题”并且至少有一个是空白的，则返回 null。

   下面是我创建的示例集，希望能展示我在说什么:

   public List<SummaryReport> CreateReport()
   {
        return Get()
            .SelectMany(rev => rev.Assessments, (rev, ass) => new { rev, ass })
            .Select(x => new SummaryReport
            {
                ReviewID = x.rev.ReviewID,
                ReviewerID = x.ass.Reviewer.ReviewerID,
                Assessment = x.ass.Assessment,
                ReviewGroupID = x.ass.Reviewer.ReviewGroup.ReviewGroupID,
                GroupAssessment = "Need to derive this value!!??!?"
             })
            .ToList();
    }
   
   public List<Review> Get()
   {
       ReviewGroup GrpOne = new ReviewGroup(){ ReviewGroupID=1};
       ReviewGroup GrpTwo = new ReviewGroup(){ ReviewGroupID=2};
       ReviewGroup GrpThree = new ReviewGroup(){ ReviewGroupID=3};
   
       ReviewerInfo userOne = new ReviewerInfo() { ReviewerID=1, ReviewGroup = GrpOne};
       ReviewerInfo userTwo = new ReviewerInfo() { ReviewerID=2, ReviewGroup = GrpTwo};
       ReviewerInfo userThree = new ReviewerInfo() { ReviewerID=3, ReviewGroup = GrpTwo};
       ReviewerInfo userFour = new ReviewerInfo() { ReviewerID=4, ReviewGroup = GrpThree};
   
       Assessment asOne = new Assessment() { AssessmentID=1, Reviewer=userOne, Assessment="Big Problem"};
       Assessment asTwo = new Assessment() { AssessmentID=2, Reviewer=userTwo, Assessment="No Problem"};
       Assessment asThree = new Assessment() { AssessmentID=3, Reviewer=userThree, Assessment="No Problem"};
       Assessment asFour = new Assessment() { AssessmentID=4, Reviewer=userFour, Assessment=""};
   
       Assessment asFive = new Assessment() { AssessmentID=5, Reviewer=userOne, Assessment="No Problem"};
       Assessment asSix = new Assessment() { AssessmentID=6, Reviewer=userTwo, Assessment="No Problem"};
       Assessment asSeven = new Assessment() { AssessmentID=7, Reviewer=userThree, Assessment="No Problem"};
       Assessment asEight = new Assessment() { AssessmentID=8, Reviewer=userFour, Assessment="No Problem"};
   
       Assessment asNine = new Assessment() { AssessmentID=9, Reviewer=userOne, Assessment="No Problem"};
       Assessment asTen = new Assessment() { AssessmentID=10, Reviewer=userTwo, Assessment=""};
       Assessment asEleven = new Assessment() { AssessmentID=11, Reviewer=userThree, Assessment="No Problem"};
       Assessment asTwelve = new Assessment() { AssessmentID=12, Reviewer=userFour, Assessment="No Problem"};
   
       List<Assessment> firstList = new List<Assessment>() { asOne, asTwo, asThree, asFour };
       List<Assessment> secondList = new List<Assessment>() {asFive, asSix, asSeven, asEight};
       List<Assessment> thirdList = new List<Assessment>() { asNine, asTen, asEleven, asTwelve };
   
       Review revOne = new Review() { ReviewID=1, Assessments=firstList };
       Review revTwo = new Review() { ReviewID=2, Assessments = secondList };
       Review revThree = new Review() { ReviewID = 3, Assessments = thirdList };
   
       List<Review> reviews = new List<Review>() { revOne, revTwo, revThree };
   
       return reviews;
   }
   
   public class SummaryReport
   {
       public int ReviewID { get; set; }
       public int ReviewerID { get; set; }
       public string Assessment { get; set; }
       public int ReviewGroupID { get; set; }
       public string GroupAssessment { get; set; }
    }
   
   public class Review
   {
        public int ReviewID { get; set; }
        public virtual List<Assessment> Assessments { get; set; }
        public Review() { }
   }
   
   public class Assessment
   {
        public int AssessmentID { get; set; }
        public ReviewerInfo Reviewer { get; set; }
        public string Assessment { get; set; }
   }
   
   public class ReviewerInfo
   {
        public int ReviewerID { get; set; }
        public ReviewGroup ReviewGroup { get; set; }
   }
   
   public class ReviewGroup
   {
        public int ReviewGroupID { get; set; }
   }
   

Answer 1

您可以定义一个方法，并在投影期间调用它。

注意:将 Assessment.Assessment 属性更改为 Assessment.AssessmentDescription，这样属性名称就不会与封闭类型相同

public List<SummaryReport> CreateReport()
{
 return Get()
     .SelectMany(rev => rev.Assessments, (rev, ass) => new { rev, ass })
     .Select(x => new SummaryReport
     {
         ReviewID = x.rev.ReviewID,
         ReviewerID = x.ass.Reviewer.ReviewerID,
         Assessment = x.ass.Assessment,
         ReviewGroupID = x.ass.Reviewer.ReviewGroup.ReviewGroupID,
         GroupAssessment = DeriveGroupAssessment(x.rev.Assessments)
      })
     .ToList();
 }


private static string DeriveGroupAssessment(IEnumerable<Assessment> assessments)
{
  string assessment = null;

  if (assessments.Any(a => a.AssessmentDescription == "Big Problem"))
  {
    assessment = "Big Problem";
  }
  else if (assessments.All(a => a.AssessmentDescription == "No Problem"))
  {
    assessment = "No Problem";
  }

  // If you want the value to be null if neither of the above conditions are met, this logic is not needed
  ////if (!assessments.Any(a => a.AssessmentDescription == "Big Problem")
  ////    && assessments.Any(a => a.AssessmentDescription == string.Empty))
  ////{
  ////  assessment = null;
  ////}

  return assessment;
}