Gets all the keys in the NameValueCollection.
Assembly: System (in System.dll)
If the collection is empty, this method returns an empty String array, not nullptr.
The arrays returned by are cached for better performance and are automatically refreshed when the collection changes. A derived class can invalidate the cached version by calling InvalidateCachedArrays, thereby forcing the arrays to be recreated.
This method is an O(n) operation, where n is Count.
Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.