LINQ Group By into Dictionary Object

Question

我正在尝试使用LINQ来创建Dictionary<string, List<CustomObject>>一个List<CustomObject>.我可以使用"var"来使用它,但我不想使用匿名类型.这就是我所拥有的

var x = (from CustomObject o in ListOfCustomObjects
      group o by o.PropertyName into t
      select t.ToList());

我曾经尝试过使用Cast<>()LINQ库x,但是我遇到了编译问题,因为它是一个无效的强制转换.

Answer 1

Dictionary<string, List<CustomObject>> myDictionary = ListOfCustomObjects
    .GroupBy(o => o.PropertyName)
    .ToDictionary(g => g.Key, g => g.ToList());

Answer 2

我无法评论@Michael Blackburn,但我猜你得到了downvote,因为在这种情况下GroupBy不是必需的.

使用它像:

var lookupOfCustomObjects = listOfCustomObjects.ToLookup(o=>o.PropertyName);
var listWithAllCustomObjectsWithPropertyName = lookupOfCustomObjects[propertyName]

另外,我已经看到这种方式比使用GroupBy()更好.ToDictionary().