Question

我坚持逻辑。我列出了

List<KeyValuePair<int, string>> items = new List<KeyValuePair<int, string>>();

项目的输出将是

0,AOP
1,AOP
2,AOP
3,Solid
4,Solid

我需要获得相同值的键（AOP = 0,1,2）。怎么能实现这一目标？

Answer 1

您可以按值进行分组：

var groups = times.GroupBy(item => item.Value).ToList();

foreach(var g in groups)
{
  Console.WriteLine("Value = " + g.Key);

  foreach(var member in g)
  {
    Console.WriteLine("\tKey = " + member.Key);
  }
}

Answer 2

您似乎有两个结果，所以我会为您提供两种结果。

        List<KeyValuePair<int, string>> items = new List<KeyValuePair<int, string>>()
        {
            new KeyValuePair<int, string>(0, "AOP"),
            new KeyValuePair<int, string>(1, "AOP"),
            new KeyValuePair<int, string>(2, "AOP"),
            new KeyValuePair<int, string>(3, "Solid"),
            new KeyValuePair<int, string>(4, "Solid"),
        };

        // assuming we want to group key
        foreach (var value in items.GroupBy(keyValuePair => keyValuePair.Key))
        {
            Console.WriteLine(value.Key);
        }

        // now lets invert the keys and values
        foreach (var value in items.GroupBy(keyValuePair => keyValuePair.Value))
        {
            IList<int> allValues = value.Select(item => item.Key).ToList();
            Console.WriteLine("{0}={1}", value.Key, allValues.Select(v => v.ToString()).Aggregate((a, b) => a + "," + b));            }
        }

Answer 3

试试这个

这将为您提供字典，其中您的值为键，值为具有相同值的键列表。

Dictionary<string, List<int>> result = items.GroupBy(d => d.Value).ToDictionary(t => t.Key, t => t.Select(r => r.Key).ToList());

使用List中的KeyValuePair中的值获取密钥

3 个答案: