How to insert an item into a key/value pair object?

List<KeyValuePair<string, string>> kvpList = new List<KeyValuePair<string, string>>()
{
    new KeyValuePair<string, string>("Key1", "Value1"),
    new KeyValuePair<string, string>("Key2", "Value2"),
    new KeyValuePair<string, string>("Key3", "Value3"),
};

kvpList.Insert(0, new KeyValuePair<string, string>("New Key 1", "New Value 1"));

Using this code:

foreach (KeyValuePair<string, string> kvp in kvpList)
{
    Console.WriteLine(string.Format("Key: {0} Value: {1}", kvp.Key, kvp.Value);
}

the expected output should be:

Key: New Key 1 Value: New Value 1
Key: Key 1 Value: Value 1
Key: Key 2 Value: Value 2
Key: Key 3 Value: Value 3

The same will work with a KeyValuePair or whatever other type you want to use..

Edit –

To lookup by the key, you can do the following:

var result = stringList.Where(s => s == "Lookup");

You could do this with a KeyValuePair by doing the following:

var result = kvpList.Where (kvp => kvp.Value == "Lookup");