使用foreach枚举内部字典

Question

我有一本词典的字典，我似乎无法弄清楚如何在内部字典中做一个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){ 
    .... 
    } 
} 

还是有点LINQ

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

     } 

通过用户名

 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

//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 4

您是否在寻找这个命令？

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

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

是字面回答你的问题;尽管我通常会推荐使用TryGet方法，除非您是某些someKey位于字典的Keys集合中。

Answer 6

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