C# 序列选择

Question

只是我想找到任何 CustomerData 的 intColl 的长度是个位数，然后选择那个 customerData。

List<CustomerData> cdata = new List<CustomerData>();

cdata.Add(
           new CustomerData { Key = 1, Name = "Marc",
                              intColl = new List<int>() { 1, 2, 3 }
                             }
         );


cdata.Add(
           new CustomerData { Key = 2, Name = "Eric",
                             intColl = new List<int>() { 11, 12, 13 }
                            }
         );


cdata.Add(
           new CustomerData { Key = 3, Name = "Peter", 
                              intColl = new List<int>() { 111, 112, 113 }
                             }
         );  


cdata.Add(
            new CustomerData { Key = 4, Name = "Peter",
                               intColl = new List<int>() { 1111, 1112, 1113 }
                             }
          );

执行以下操作时

var query = cdata.Any(d => d.intColl.Find(c => c == 1));

我收到了

无法将类型“int”隐式转换为“bool”。

Answer 1

虽然您编写的查询应该写成，

var query = cdata.Any(d => d.intColl.Contains(1));

我认为，根据您的问题文本，您应该这样做:

var query = cdata.Any(d => d.intColl.Any(c => c < 10 && c >= 0));

并返回实际对象(根据评论):

var query = cdata.FirstOrDefault(d => d.intColl.Any(c => c < 10 && c >= 0));
if (query == null) { /* nothing fits the criteria */ }
else { /* use `query` object */ }