在 C# 中将字典转换为列表集合

Question

I have a problem when trying to convert a dictionary to list.

Example if I have a dictionary with template string as key and string as value. Then I wish to convert the dictionary key to list collection as a string.

Dictionary<string, string> dicNumber = new Dictionary<string, string>();
List<string> listNumber = new List<string>();

dicNumber.Add("1", "First");
dicNumber.Add("2", "Second");
dicNumber.Add("3", "Third");

// So the code may something look like this
//listNumber = dicNumber.Select(??????);

Answer 1

To convert the Keys to a List of their own:

listNumber = dicNumber.Select(kvp => kvp.Key).ToList();

Or you can shorten it up and not even bother using select:

listNumber = dicNumber.Keys.ToList();

Answer 2

或者：

var keys = new List<string>(dicNumber.Keys);

Answer 3

如果要使用Linq，则可以使用以下代码段：

var listNumber = dicNumber.Keys.ToList();

Answer 4

If you want convert Keys:

List<string> listNumber = dicNumber.Keys.ToList();

else if you want convert Values:

List<string> listNumber = dicNumber.Values.ToList();

Answer 5

foreach (var item in dicNumber)
{
    listnumber.Add(item.Key);
}

Answer 6

If you want to pass the Dictionary keys collection into one method argument.

List<string> lstKeys = Dict.Keys;
Methodname(lstKeys);
-------------------
void MethodName(List<String> lstkeys)
{
    `enter code here`
    //Do ur task
}

Answer 7

List<string> keys = dicNumber.Keys.ToList();
List<string> values = keys.Select(i => dicNumber[i]).ToList();

This ensures that dicNumber[keys[index]] == values[index] for each possible index .