C＃从字典获取值 <string, List<object> &gt;

Question

I have a question about how to get values from my Dictionary<string, List<object>> , I tried all examples which I found in google, but still can't get something readable value.....

so, here is the code:

List<object> listValues = new List<object>();
listValues.Add(risk);
listValues.Add(validFrom);
listValues.Add(effectiveDate);

Dictionary<string, List<object>> dic = new Dictionary<string, List<object>>();
dic.Add(nameOfInsuredObject, listValues);

foreach (object value in dic.Values)
{
  System.Console.WriteLine(value);
}

I can get key from dictionary, but with getting value I am stucked now.... And here is the result of this code:

Key => testInsObj
Values => System.Collections.Generic.List`1[System.Object]

So can anyone help me with it? I am new in C#, so maybe this is easy questions for others....

Answer 1

It is confusing for new C# users, how to access the dictionary.

When you do a foreach on the dictionary, you get a KeyValuePair<TKey, TValue> . Now this KeyValuePair<TKey, TValue> , has 2 properties KeyValuePair.Key and KeyValuePair.Value , representing the Key and Value stored in the dictionary.

Also, the Value in your case is a List<T> , which means doing a Console.WriteLine on it will not print the whole List<T> (as some people expect), but just some reference string. You will have to "loop" over the list to print individual elements. Needless to say, depending on what you want to do with the element in the List<T> , you can use LINQ or some other common C# idiom.

foreach (var value in dic) {
    Console.WriteLine(value.Key);
    foreach (var item in value.Value)
        Console.WriteLine(item);
}

Answer 2

It seems you are looking for writing values of the list this way:

foreach (var value in dic.Values)
{
    value.ForEach(Console.WriteLine);
}

In fact each element of the Dictionary is <string, List<Object>> . So, when you want to write Value part of the pair to console, you need a for loop to write each element of the List<object> .