C＃从嵌套字典中删除项目

Question

I've got a simple question that my mind is drawing a blank to: I have a Dictionary that looks something like this:

Dictionary<string, Dictionary<string, string>> dict;

As far as I know, dict.Remove() would remove any entry by key, but I need to only remove an item from the innermost dictionary. How would I go about that?

Answer 1

Well presumably you've got two keys: one for the outer dictionary and one for the nested one.

So assuming you know that the entry is present, you can use

dict[outerKey].Remove(innerKey);

If you don't know whether the entry exists, you want something like:

Dictionary<string, string> innerDict;
if (dict.TryGetValue(outerKey, out innerDict))
{
    // It doesn't matter whether or not innerKey exists beforehand
    innerDict.Remove(innerKey);
}

Answer 2

If you just have the inner key, you can do something like this:

string removeKey = "42";

Dictionary<String, String> removeDict = dict.Select(d=> d.Value).FirstOrDefault(d => d.ContainsKey(removeKey));

if(removeDict !=null)  
    removeDict.Remove(removeKey);

In this implementation if there is more then one register with the same innerKey just the first occurrence will be removed

Answer 3

Try

dict["key"].Remove("childkey");

Notice the keys are string values.