Question

我有一本字典词典，我似乎无法弄清楚如何在内部字典中进行foreach循环。

我的收藏：

Dictionary<int, Dictionary<int, User>>

到目前为止，我有：

foreach(User user in myDic[someKey]??)

Answer 1

嵌套的foreach

foreach (var keyValue in myDic){
   foreach (var user in keyValue.Value){
     ....
   }
}

或一点linq

        foreach (User User in myDic.SelectMany(i => i.Value).Select(kv=>kv.Value))
        {

        }

按UserName排序

        foreach (User User in myDic.SelectMany(i => i.Value)
                                   .Select(kv=>kv.Value)
                                   .OrderBy(u=>u.UserName))
        {

        }

Answer 2

foreach (KeyValuePair<int, Dictionary<int, User>> users in myDic) {
    foreach (KeyValuePair<int, User> user in users.Value) {
        ...
    }
}

Answer 3

foreach(User user in myDic[someKey].Values)

是你问题的字面答案;虽然我通常建议使用TryGet方法，除非你某些 someKey在你的词典的Keys集合中。

Answer 4

你在找这个吗？

    var myDic = new Dictionary<int, Dictionary<int, string>>();
    foreach(var item in myDic)
        foreach (var subItem in item.Value)
        {
            Display(
                subItem.Key,    // int
                subItem.Value); // User
        }

Answer 5

//given: Dictionary<int, Dictionary<int, User>> myDic

foreach(KeyValuePair<int, Dictionary<int, User>> kvp in myDic) {
   foreach(KeyValuePair<int, User> kvpUser in kvp.Value) {
      User u = kvpUser.Value;
   }
}

Answer 6

var users = myDic.Select(kvp => kvp.Value).SelectMany(dic => dic.Values);
foreach(User user in users)
{
   ...
}

使用foreach枚举内部字典

6 个答案: