使用LINQ合并2个列表并汇总多个属性

我有一个包含以下属性的类：

public class SomeClass() { public Int32 ObjectId1 {get;set;} public Int32 ObjectId2 {get;set;} public Int32 ActiveThickeness {get;set;} public Int32 ActiveFilterThickness {get;set;} } 

我还有2个列表：

 List A List B 

列表A有数据：

 | ObjectId1 | ObjectId2 | ActiveThickness | ActiveFilterThickness | ------------------------------------------------------------------- | 1 | 3 | 50 | 0 | ------------------------------------------------------------------ | 1 | 2 | 400 | 0 | ------------------------------------------------------------------- | 4 | 603 | 27 | 0 | ------------------------------------------------------------------- 

清单B有数据：

 | ObjectId1 | ObjectId2 | ActiveThickness | ActiveFilterThickness | ------------------------------------------------------------------- | 1 | 3 | 0 | 13671 | ------------------------------------------------------------------ | 1 | 2 | 0 | 572 | ------------------------------------------------------------------- | 29 | 11 | 0 | 4283 | ------------------------------------------------------------------- 

我想将A和B（如果可能，使用LINQ）合并到SomeCalss的List C中，其中包含如下数据：

 | ObjectId1 | ObjectId2 | ActiveThickness | ActiveFilterThickness | ------------------------------------------------------------------- | 1 | 3 | 50 | 13671 | ------------------------------------------------------------------ | 1 | 2 | 400 | 572 | ------------------------------------------------------------------- | 29 | 11 | 0 | 4283 | ------------------------------------------------------------------- | 4 | 603 | 27 | 0 | ------------------------------------------------------------------- 

我怎样才能做到这一点？

Answer 1

使用GroupBy对公共对象进行分组，使用Sum对所需属性求和

  var ab = A.Concat(B).GroupBy(x => new { x.ObjectId1, x.ObjectId2 }); var result = ab.Select(x => new SomeClass { ObjectId1 = x.Key.ObjectId1, ObjectId2 = x.Key.ObjectId2, ActiveFilterThickness = x.Sum(i => i.ActiveFilterThickness), ActiveThickeness = x.Sum(i => i.ActiveThickeness) }); 

Answer 2

请参阅LINQ – 完全外部加入 （SO）。

通过左外连接和右外连接，然后取两者的结合，你应该得到你正在寻找的东西。

 var leftOuterJoin = from someclass1 in A join someclass2 in B on someclass1.ObjectID2 equals someclass2.ObjectID2 into temp from item in temp.DefaultIfEmpty(new SomeClass(){ objectID1 = someclass1.objectID1, ... }) select new SomeClass() { ... }; var rightOuterJoin = from someclass2 in B join someclass1 in A on someclass1.ObjectID2 equals someclass2.ObjectID2 into temp from item in temp.DefaultIfEmpty(new SomeClass(){ objectID1 = someclass1.objectID1, ... }) select new SomeClass() { ... }; var fullOuterJoin = leftOuterJoin.Union(rightOuterJoin);