如何基於財產

Question

得到兩班的十字路口，我有這個類

public class FlightSegment{ 
    public string ClassName { get;set;} 
} 

我想FlightSegments共同ClassName

void Main() 
{ 
    var list1 = new List<FlightSegment>() { 
     new FlightSegment{ ClassName = "A"}, 
     new FlightSegment { ClassName = "B"} 
    };  
    var list2 = new List<FlightSegment>() { 
     new FlightSegment{ ClassName = "B"}, 
     new FlightSegment { ClassName = "C"} 
    }; 

    var listOfLists = new List<List<FlightSegment>>() { list1, list2 };  
    var intersection = listOfLists.Aggregate((previousList, nextList) => previousList.Intersect(nextList).ToList());   
    Console.WriteLine(intersection); //Gives me empty result 

} 

我想是這樣的：

var intersection = listOfLists.Aggregate((previousList, nextList) => 
     previousList.Select(e=>e.ClassName).Intersect(nextList.Select(e=>e.ClassName)).ToList()); 

但給出錯誤：

Cannot convert expression type System.Collection.Generic.List<string> to return type System.Collection.Generic.List<FlightSegment> 

Answer 1

您可以使用Intersect方法傳遞IEqualityComparer根據ClassName性能比較：

var list1 = new List<FlightSegment>() { 
    new FlightSegment{ ClassName = "A"}, 
    new FlightSegment { ClassName = "B"} 
};  
var list2 = new List<FlightSegment>() { 
    new FlightSegment{ ClassName = "B"}, 
    new FlightSegment { ClassName = "C"} 
}; 
var result = list1.Intersect(list2, new FlightComparer()); 

這僅返回包含集合：

class FlightComparer : EqualityComparer<FlightSegment> 
{ 
    public override bool Equals(FlightSegment x, FlightSegment y) 
    { 
     return x.ClassName == y.ClassName; 
    } 

    public override int GetHashCode(FlightSegment obj) 
    { 
     return obj.ClassName.GetHashCode(); 
    } 
} 

然後，使用該比較器進行交叉點一個元素FlightSegment { ClassName = "B" }。

使用這個想法，並Aggregate，你可以根據屬性組列表的交集：

var intersection = listOfLists.Aggregate((previousList, nextList) => previousList.Intersect(nextList, new FlightComparer()).ToList());