Use the Mask property to filter characters during data input. Use the Mask property to control the entry of many types of formatted information such as telephone numbers, social security numbers, IP addresses, license keys etc.  The Mask property has effect for the following edit types: DropDownType, SpinType, DateType, MaskType, FontType, PickEditType. The Numeric property specifies whether the editor enables numeric values only. Use the MaskChar property to change the masking character.  If the Mask property is empty no filter is applied. The Mask property is composed by a combination of regular characters, literal escape characters, and masking characters. The Mask property can contain also alternative characters, or range rules. A literal escape character is preceded by a \ character, and it is used to display a character that is used in masking rules. 

Here's the list of all rules and masking characters:

• # (Digit), Masks a digit character. [0-9]
• x (Hexa Lower), Masks a lower hexa character. [0-9],[a-f]
• X (Hexa Upper), Masks a upper hexa character. [0-9],[A-F]
• A (AlphaNumeric), Masks a letter or a digit. [0-9], [a-z], [A-Z]
• ? (Alphabetic), Masks a letter. [a-z],[A-Z]
• < (Alphabetic Lower), Masks a lower letter. [a-z]
• > (Alphabetic Upper), Masks an upper letter. [A-Z]
• * (Any), Mask any combination of characters.
• \ (Literal Escape), Displays any masking characters. The following combinations are valid: \#,\x,\X,\A,\?,\<,\>,\\,\{,\[
• {nMin,nMax} (Range), Masks a number in a range. The nMin and nMax values should be numbers. For instance the mask {0,255} will mask any number between 0 and 255.
• [...] (Alternative), Masks any characters that are contained by brackets []. For instance, the [abcA-C] mask any character: a,b,c,A,B,C

The following VB sample adds a mask for IP addresses:

With Grid1
    With .Columns.Add("Mask")
        With .Editor
            .EditType = EditTypeEnum.MaskType
            .Mask = "{0,255}\.{0,255}\.{0,255}\.{0,255}"
        End With
    End With
    .Items.AddItem "193.226.40.161"
End With

The following VB sample masks a phone number:

With Grid1
    With .Columns.Add("Mask")
        With .Editor
            .EditType = EditTypeEnum.MaskType
            .Mask = "(XXX) - XXX XXXX"
        End With
    End With
    .Items.AddItem "(095) - 889 1234"
End With

The following C++ adds a mask editor to filter characters while entering a phone number:

#include "Items.h"
#include "Editor.h"
COleVariant vtMissing; V_VT( &vtMissing) = VT_ERROR;
CItems items = m_grid.GetItems();
CEditor editor = items.GetCellEditor( COleVariant( items.GetFirstVisibleItem() ), COleVariant( long(0) ) );
editor.SetEditType( 8 /*MaskType*/ );
editor.SetMask("(###) ### - ####");

The following VB.NET adds a mask editor to filter characters while entering a phone number:

With AxGrid1.Items
    With .CellEditor(.FirstVisibleItem, 0)
        .EditType = EXGRIDLib.EditTypeEnum.MaskType
        .Mask = "(###) ### - ####"
    End With
End With

The following C# adds a mask editor to filter characters while entering a phone number:

EXGRIDLib.Items items = axGrid1.Items;
EXGRIDLib.Editor editor = items.get_CellEditor(items.FirstVisibleItem, 0);
editor.EditType = EXGRIDLib.EditTypeEnum.MaskType;
editor.Mask = "(###) ### - ####";

The following VFP adds a mask editor to filter characters while entering a phone number:

with thisform.Grid1.Items
	With .CellEditor(.FirstVisibleItem, 0) 
		.EditType = 8 && MaskType
		.Mask = "(###) ### - ####"
	EndWith
endwith