C# appending Dictionary
append, c#, concatenation, dictionary
Solution
I once wrote an extension method for that because I needed the same. The last parameter decides what to do when duplicate keys are encountered.
`Skip` means source entry is kept.
`Overwrite` means "other" entry is used.
`Throw` will throw an Exception.
public enum DuplicateKeyHandling
{
Skip,
Overwrite,
Throw
}
/// <summary>
/// Combines two dictionaries into one dictionary. The contents of the resulting dictionary depends on the <paramref name="duplicateKeyHandling"/> parameter.
/// </summary>
/// <typeparam name="TKey">The type of the keys in the dictionaries</typeparam>
/// <typeparam name="TValue">The type of the values in the dictionaries</typeparam>
/// <param name="this"></param>
/// <param name="other">The dictionary to combine this one with</param>
/// <param name="duplicateKeyHandling">Specifies how to react if the <paramref name="other"/> dictionary contains keys that are already in this dictionary</param>
/// <returns>A new dictionary containing the combined key-value-pairs of both source dictionaries</returns>
public static Dictionary<TKey, TValue> Combine<TKey, TValue>(this Dictionary<TKey, TValue> @this, Dictionary<TKey, TValue> other, DuplicateKeyHandling duplicateKeyHandling = DuplicateKeyHandling.Skip)
{
// EDIT: I added the "comparer" parameter so the resulting dictionary will
// use the same comparer as the first source dictionary
var result = new Dictionary<TKey, TValue>(@this, @this.Comparer);
foreach (KeyValuePair<TKey, TValue> kvp in other)
{
if (result.ContainsKey(kvp.Key))
{
if (duplicateKeyHandling == DuplicateKeyHandling.Overwrite)
{
result[kvp.Key] = kvp.Value;
}
if (duplicateKeyHandling == DuplicateKeyHandling.Throw)
{
throw new Exception("Duplicate key while combining dictionaries!");
}
}
else
{
result.Add(kvp.Key, kvp.Value);
}
}
return result;
}
Problem
how can i append Dictionary into another Dictionary ? ``` Dictionary<string, DateTime> odict = new Dictionary<string, DateTime>(); //Liste tous les Clients EMAIL (3) foreach (var TheClientID in TheClient.GetClient_Id(3)) { Dictionary<string, DateTime> Temp = oEmail.VoirEML(TheClientID.Key); //odict = odict.Concat(Temp).ToDictionary(pair => pair.Key, pair => pair.Value); odict = odict.SelectMany(toto => Temp) .ToLookup(pair => pair.Key, pair => pair.Value) .ToDictionary(group => group.Key, group => group.First()); } ``` i want to concat / append dictionary without double the entry.