C#中两个List<TModel>中根据指定条件--判断并获取不同数据的数据集合
原始需求:已经插入的数据不再重复插入(所有数据中排除已有数据,不存在数据以新对象形式存储在对象三种)
方式一:
public class Test { public int age { get; set; } public string name { get; set; } public int score { get; set; } }
List<Test> list1 = new List<Test>(); list1.Add(new Test { score = 10, name = "001" }); list1.Add(new Test { score = 20, name = "002" }); list1.Add(new Test { score = 30, name = "003" }); list1.Add(new Test { score = 40, name = "004" }); list1.Add(new Test { score = 50, name = "005" }); list1.Add(new Test { score = 60, name = "005" }); List<Test> list2 = new List<Test>(); list2.Add(new Test { score = 10, name = "001" }); list2.Add(new Test { score = 20, name = "002" }); list2.Add(new Test { score = 30, name = "003" }); list2.Add(new Test { score = 40, name = "004" }); //list3 return 2 List<Test> list3 = list1.Where(x => !list2.Any(x2 => x.score == x2.score)).ToList(); //list4 return 2 List<Test> list4 = list1.Where(x => list2.All(x2 => x.score != x2.score)).ToList(); MessageBox.Show("list3==" + list3.Count+" list4==" + list4.Count);
方式二:list1、list2数据参考方式一
public class DifferentModel : IEqualityComparer<Test> { public bool Equals(Test x, Test y) { return x.score == y.score; } public int GetHashCode(Test obj) { return obj.ToString().GetHashCode(); } } List<Test> different = list1.Except(list2, new DifferentModel()).ToList();//差集 MessageBox.Show("different=="+different.Count);
方式三:仅供参考,根据实际情况注意Contains关键字 注意使用——不建议使用
//return 2
List<Test> temp = list1.Where(p => !list2.Select(b => b.score).Contains(p.score)).ToList();
MessageBox.Show("temp=="+temp.Count);