TryAdd
You should have this already: https://learn.microsoft.com/en-us/dotnet/api/system.collections.generic.dictionary-2.tryadd?view=net-7.0 but this is not always available in all environments.
Source
/// <summary> Purpose: Prevents exception "Item with Same Key has already been added". </summary>
public static void TryAdd<TKey, TValue>(this Dictionary<TKey, TValue> dictionary,
TKey key, TValue value)
{
if (!dictionary.ContainsKey(key))
{
dictionary.Add(key, value);
}
}Example
// where Scenario is a custom object
Dictionary<Type, PageDrawerItem> targetViewDict = new Dictionary<Type, PageDrawerItem>();
targetViewDict.TryAdd(typeof(Scenario), mainVM.GetView(PageKind.Scenarios));