使用LINQ从Dictionary获取键值组合

Question

假设我有以下字典:

private Dictionary<string, IEnumerable<string>> dic = new Dictionary<string, IEnumerable<string>>();

//.....
dic.Add("abc", new string[] { "1", "2", "3" });
dic.Add("def", new string[] { "-", "!", ")" });

如何获得IEnumerable<Tuple<string, string>>包含以下组合的内容:

{
     { "abc", "1" },
     { "abc", "2" },
     { "abc", "3" },
     { "def", "-" },
     { "def", "!" },
     { "def", ")" }
}

它并不必须是一个Tuple<string, string>,但它似乎是更appropiate类型.

我正在寻找一个简单的LINQ解决方案,如果有的话.

我尝试过以下方法:

var comb = dic.Select(i => i.Value.Select(v => Tuple.Create<string, string>(i.Key, v)));

但comb最终成为了类型IEnumerable<IEnumerable<Tuple<string, string>>>.

Answer 1

你想要Enumerable.SelectMany哪个会弄平你的IEnumerable<IEnumerable<T>>:

var comb = dic.SelectMany(i => i.Value.Select(
                               v => Tuple.Create(i.Key, v)));

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