public static void SetLicense( string serialKey )
Public Shared Sub SetLicense ( serialKey As String )
You should call this method before using any other class from GemBox.Spreadsheet library. Key can only be set once (if you try second key, exception will be thrown). The best place to call this method is from static constructor of your application's main class.
Valid serial key has multiple groups of alphanumeric characters, separated with dashes.
Free version serial key is: FREE-LIMITED-KEY.