'Declaration Public Property Mode As SpellCheckingMode
public SpellCheckingMode Mode {get; set;}
The Mode property determines how objects are spell checked. They can be spell checked as the user types, spell checked with a dialog after the user is done editting the text, neither, or both.
When the mode is set to SpellCheckingMode.AsYouType, each time the user spaces out of a word, that word will be spell checked. If that word contains a spelling error, the SpellError event will be fired.
When the mode is set to SpellCheckingMode.DialogOnValidating, and the user leaves the control or object being editted, the text is spell checked in a spell checking dialog.
Setting the mode to SpellCheckingMode.DialogOnValidatingAndAsYouType uses a combination of both behaviors mentioned above.
Target Platforms: Windows 10, Windows 8.1, Windows 8, Windows 7, Windows Server 2012, Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2