如:
var fc =...
ChildFath = fc.Select(c => new Child_Father { child = c.child, father = c.father }).Distinct().Where(c => c.father != c.child).ToList();
也可不事先定义类型
var aa=fc.Select(c => new { c.child, c.father }).Distinct().Where(c=>c.child==aa").ToList();