我正在寻找一种非常快速的方法来检查对象列表中的重复项。检查对象列表中的重复项#
我想简单地通过列表循环和做手工比较这种方式,但我认为LINQ可能会提供一个更好的解决方案...
假设我有一个对象...
public class dupeCheckee
{
public string checkThis { get; set; }
public string checkThat { get; set; }
dupeCheckee(string val, string val2)
{
checkThis = val;
checkThat = val2;
}
}
而且我的那些对象
List<dupeCheckee> dupList = new List<dupeCheckee>();
dupList.Add(new dupeCheckee("test1", "value1"));
dupList.Add(new dupeCheckee("test2", "value1"));
dupList.Add(new dupeCheckee("test3", "value1"));
dupList.Add(new dupeCheckee("test1", "value1"));//dupe
dupList.Add(new dupeCheckee("test2", "value1"));//dupe...
dupList.Add(new dupeCheckee("test4", "value1"));
dupList.Add(new dupeCheckee("test5", "value1"));
dupList.Add(new dupeCheckee("test1", "value2"));//not dupe
我需要找到该列表中的受骗者名单。当我找到它时,我需要做一些额外的逻辑 不一定删除它们。
当我使用LINQ一些我的GroupBy如何抛出异常......
'System.Collections.Generic.List<dupeCheckee>' does not contain a definition for 'GroupBy' and no extension method 'GroupBy' accepting a first argument of type 'System.Collections.Generic.List<dupeCheckee>' could be found (are you missing a using directive or an assembly reference?)
这是告诉我,我缺少的库。我很难搞清楚哪一个。
一旦我弄清楚,但我怎么会基本上检查这两个条件... IE checkThis和checkThat都出现不止一次?
更新:我想出了
这是我想出了做快速研究后LINQ查询...
test.Count != test.Select(c => new { c.checkThat, c.checkThis }).Distinct().Count()
我不能肯定这是否是肯定更好比这个答案...
var duplicates = test.GroupBy(x => new {x.checkThis, x.checkThat})
.Where(x => x.Skip(1).Any());
我知道我可以把第一条语句放入if else子句。我也跑了一个快速测试。重复列表给我回1当我期待0,但它确实正确地呼吁我有一套我使用的重复的事实...
其他方法完全按照我的预期。下面是我用它来测试此数据集....
愚弄:
List<DupeCheckee> test = new List<DupeCheckee>{
new DupeCheckee("test0", "test1"),//{ checkThis = "test", checkThat = "test1"}
new DupeCheckee("test1", "test2"),//{ checkThis = "test", checkThat = "test1"}
new DupeCheckee("test2", "test3"),//{ checkThis = "test", checkThat = "test1"}
new DupeCheckee("test3", "test3"),//{ checkThis = "test", checkThat = "test1"}
new DupeCheckee("test0", "test5"),//{ checkThis = "test", checkThat = "test1"}
new DupeCheckee("test1", "test6"),//{ checkThis = "test", checkThat = "test1"}
new DupeCheckee("test2", "test7"),//{ checkThis = "test", checkThat = "test1"}
new DupeCheckee("test3", "test8"),//{ checkThis = "test", checkThat = "test1"}
new DupeCheckee("test0", "test5"),//{ checkThis = "test", checkThat = "test1"}
new DupeCheckee("test1", "test1"),//{ checkThis = "test", checkThat = "test1"}
new DupeCheckee("test2", "test2"),//{ checkThis = "test", checkThat = "test1"}
new DupeCheckee("test3", "test3"),//{ checkThis = "test", checkThat = "test1"}
new DupeCheckee("test4", "test4"),//{ checkThis = "test", checkThat = "test1"}
};
没有愚弄......
List<DupeCheckee> test2 = new List<DupeCheckee>{
new DupeCheckee("test0", "test1"),//{ checkThis = "test", checkThat = "test1"}
new DupeCheckee("test1", "test2"),//{ checkThis = "test", checkThat = "test1"}
new DupeCheckee("test2", "test3"),//{ checkThis = "test", checkThat = "test1"}
new DupeCheckee("test3", "test3"),//{ checkThis = "test", checkThat = "test1"}
new DupeCheckee("test4", "test5"),//{ checkThis = "test", checkThat = "test1"}
new DupeCheckee("test5", "test6"),//{ checkThis = "test", checkThat = "test1"}
new DupeCheckee("test6", "test7"),//{ checkThis = "test", checkThat = "test1"}
new DupeCheckee("test7", "test8"),//{ checkThis = "test", checkThat = "test1"}
new DupeCheckee("test8", "test5"),//{ checkThis = "test", checkThat = "test1"}
new DupeCheckee("test9", "test1"),//{ checkThis = "test", checkThat = "test1"}
new DupeCheckee("test2", "test2"),//{ checkThis = "test", checkThat = "test1"}
new DupeCheckee("test3", "test3"),//{ checkThis = "test", checkThat = "test1"}
new DupeCheckee("test4", "test4"),//{ checkThis = "test", checkThat = "test1"}
};
将'using System.Linq;'添加到您的cs文件的顶部以使'GroupBy'工作。 – 2013-04-24 16:29:33
是的。刚刚发现我错过了它。谢谢。 – SoftwareSavant 2013-04-24 16:31:54
Erm没有愚弄有一个愚蠢的测试3,test3 – 2013-04-25 17:35:03