Adds an element with the provided key and value to the IDictionary`2.
| Exception Type | Condition | 
|---|---|
| ArgumentNullException | key is null. | 
| ArgumentException | An element with the same key already exists in the IDictionary`2. | 
| NotSupportedException | The IDictionary`2 is read-only. | 
DictionaryBase<TKey, TValue> Class | ComponentOwl.BetterThumbnailBrowser Namespace | DictionaryBase<TKey, TValue>.Add Overload List