Use EditMask to restrict the characters a user can enter. If the user attempts to enter a character that is not valid, the character is not accepted. Validation using the EditMask property is performed on a character-by-character basis. 

A mask consists of three fields with semicolons separating the fields. The first part of the mask is the mask itself. The second part is the character that determines whether the literal characters of a mask are included as part of the data. The third part of the mask is the character used to represent unentered characters in the mask.  

Setting EditMask to an empty string removes the mask. 

For more information on using edit masks, see the TEditMask type. 

Values 

OnSetEditText