如何在C#中修改字典中的键
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How to modify key in a dictionary in C#
提问by Bernard Larouche
How can I change the value of a number of keys in a dictionary.
如何更改字典中多个键的值。
I have the following dictionary :
我有以下字典：
SortedDictionary<int,SortedDictionary<string,List<string>>>
I want to loop through this sorted dictionary and change the key to key+1 if the key value is greater than a certain amount.
如果键值大于一定数量，我想遍历这个排序的字典并将键更改为键+1。
采纳答案by Dan Tao
As Jason said, you can't change the key of an existing dictionary entry. You'll have to remove/add using a new key like so:
正如杰森所说，您不能更改现有字典条目的键。您必须使用新密钥删除/添加，如下所示：
// we need to cache the keys to update since we can't
// modify the collection during enumeration
var keysToUpdate = new List<int>();
foreach (var entry in dict)
{
if (entry.Key < MinKeyValue)
{
keysToUpdate.Add(entry.Key);
}
}
foreach (int keyToUpdate in keysToUpdate)
{
SortedDictionary<string, List<string>> value = dict[keyToUpdate];
int newKey = keyToUpdate + 1;
// increment the key until arriving at one that doesn't already exist
while (dict.ContainsKey(newKey))
{
newKey++;
}
dict.Remove(keyToUpdate);
dict.Add(newKey, value);
}
回答by jason
回答by goofballLogic
If you don't mind recreating the dictionary, you could use a LINQ statment.
如果您不介意重新创建字典，则可以使用 LINQ 语句。
var dictionary = new SortedDictionary<int, SortedDictionary<string, List<string>>>();
var insertAt = 10;
var newValues = dictionary.ToDictionary(
x => x.Key < insertAt ? x.Key : x.Key + 1,
x => x.Value);
return new SortedDictionary<int, SortedDictionary<string, List<string>>>(newValues);
or
或者
var dictionary = new SortedDictionary<int, SortedDictionary<string, List<string>>>();
var insertAt = 10;
var newValues = dictionary.ToDictionary(
x => x.Key < insertAt ? x.Key : x.Key + 1,
x => x.Value);
dictionary.Clear();
foreach(var item in newValues) dictionary.Add(item.Key, item.Value);
回答by marcel
You can use LINQ statment for it
您可以使用 LINQ 语句
var maxValue = 10
sd= sd.ToDictionary(d => d.key > maxValue ? d.key : d.Key +1, d=> d.Value);
