C# linq 拆分，排序并加入值

Question

我有以下代码。 它像我一样工作。 但我想减少行代码的数量。 在 foreach 循环中，我正在进行拆分，排序并加入值。 那么我们可以用其他方式编写它吗？

class a
{
 public string Test { get; set; }
 public string Code { get; set; }
}

var masterFormList = "BBB,AAA,CCC,FFF,GGG,HHH";
List<a> mData = new List<a>();
 
mData.Add(new a { Test = "AAA,BBB,CCC,FFF,GGG,HHH", Code = "A" });
mData.Add(new a { Test = "BBB", Code = "B" });
mData.Add(new a { Test = "CCC", Code = "C" });
mData.Add(new a { Test = "FFF", Code = "D" });
mData.Add(new a { Test = "GGG", Code = "E" });
mData.Add(new a { Test = "HHH", Code = "F" });
var masterSet = masterFormList.Split(',').OrderBy(y => y);
var l = string.Join(",", masterSet);
    
    
string value = "";
foreach (var item in mData)
{
   var listSplite = item.Test.Split(',').OrderBy(y => y);
     if (l == string.Join(",", listSplite))
     {
     value = item.Code;
    
      }
  }

Answer 1

如我所见，您想查找在Test属性中给出了代码列表的元素。 为此，我会编写帮助方法并使用 LINQ 方法，如下所示：

var masterFormList = "BBB,AAA,CCC,FFF,GGG,HHH";

List<ExampleClass> mData = new List<ExampleClass>();

mData.Add(new ExampleClass { Test = "AAA,BBB,CCC,FFF,GGG,HHH", Code = "A" });
mData.Add(new ExampleClass { Test = "BBB", Code = "B" });
mData.Add(new ExampleClass { Test = "CCC", Code = "C" });
mData.Add(new ExampleClass { Test = "FFF", Code = "D" });
mData.Add(new ExampleClass { Test = "GGG", Code = "E" });
mData.Add(new ExampleClass { Test = "HHH", Code = "F" });

// You can use here also Where method that will return list of items
var masterItem = mData.FirstOrDefault(x => AreListsEquivalent(masterFormList, x.Test));

Console.ReadKey();

// Helper method to compare list in form of comma separated values.
static bool AreListsEquivalent(string list1, string list2)
{

    return list1.Split(',').ToHashSet()
        .SetEquals(list2.Split(',').ToHashSet());
}

// Test class
public class ExampleClass
{
    public string Test { get; set; }
    public string Code { get; set; }
}

Answer 2

我认为您可以只进行字符串比较，但使用 LINQ 可以更缩写：

var masterKey = String.Join(",", masterFormList.Split(',').OrderBy(y => y));

var value = mData.Where(a => masterKey == String.Join(",", a.Test.Split(',').OrderBy(y => y)))
                 .LastOrDefault()
                 ?.Code;