如何通過一個屬性值的列表中刪除重複項<>

Question

有人可以幫我把Linq查詢並告訴我怎麼拉出來的獨特產品名稱

List<StatePlan> planTypes = (from ppt in context.PlanPlanTypes 
    join pt in context.PlanTypes on ppt.PlanTypeRowID equals pt.PlanTypeRowID 
    join ppts in context.PlanPlanTypeStates on ppt.PlanPlanTypeRowID equals ppts.PlanPlanTypeRowID 
    join p in context.Plans on ppt.PlanRowID equals p.PlanRowID 
    where ppts.StateCode == stateCode 
    where p.IsActive == true 
    select new StatePlan 
    { 
     PlanID = p.PlanRowID, 
     StateCode = stateCode, 
     Name = p.Name, 
     Description = p.Description, 
     Disclaimer = p.Disclaimer, 
     Sequence = p.DisplaySequence, 
     //Rates = GetRates(p.PlanRowID), 
     //Types = GetPlanTypes(p.PlanRowID, stateCode) 
    }).ToList(); 
return planTypes; 

Answer 1

集團首先然後在第一個

List<StatePlan> planTypes = (from ppt in context.PlanPlanTypes 
              join pt in context.PlanTypes on ppt.PlanTypeRowID equals pt.PlanTypeRowID 
              join ppts in context.PlanPlanTypeStates on ppt.PlanPlanTypeRowID equals ppts.PlanPlanTypeRowID 
              join p in context.Plans on ppt.PlanRowID equals p.PlanRowID 
              where ppts.StateCode == stateCode 
              where p.IsActive == true 
              select new StatePlan 
              { 
               PlanID = p.PlanRowID, 
               StateCode = stateCode, 
               Name = p.Name, 
               Description = p.Description, 
               Disclaimer = p.Disclaimer, 
               Sequence = p.DisplaySequence, 
               //Rates = GetRates(p.PlanRowID), 
               //Types = GetPlanTypes(p.PlanRowID, stateCode) 
              }) 
              .GroupBy(g => g.Name) 
              .Select(s => s.First()) 
              .ToList(); 
      return planTypes; 

Answer 2

我不知道如果我的理解問題正確的，但如果你想有一定的不同領域的項目，你可以使用GROUPBY +第一：

seq.GroupBy(item=>item.Name).Select(group=>group.First()) 

您也可以使用投影相等比較，但我認爲這是一個有點難看。對我來說，使用Distinct意味着你不在乎你這相當於項目。而GROUPBY +首次明確指出，希望第一個。

的GroupBy，您還可以收集你的Select條款的許多項目與這樣一個名字是如何存在的其他信息，例如。

---

如果你只是想沒有相關的項目不同的名稱，結合選擇和獨特的：

seq.Select(item=>item.Name).Distinct() 

Answer 3

您可以致電Distinct和StatePlan

Distinct

Answer 4

planTypes.Select(pt=>pt.Name).Distinct(); 

提供和的IEqualityComparer

Answer 5

假設在p RODUCT名在planTypes列表中Name屬性，它是一個字符串：

List<string> productNames = planTypes.Select(t => t.Name).Distinct().ToList();