.NET Controls: The ActiveX Masked Edit Box

Microsoft Visual Basic 6.0 provides a convenient text box that allows you to assist the user with text entry in a text box. This control is called MaskEdit. To use this control, you must explicitly add it as a COM Component of the Microsoft Masked Edit Control.

The most important property of a MaskEdit control, which sets it apart from the (traditional) text box control, is its ability to control what the user can and cannot enter in the text side. To configure this text, you have two alternatives. The Format property in the Properties window provides a list of available masks you can use:

If none of the masks in the list suits you, you still have two alternatives. You can type your own desired mask in the Format field. The characters you can use are:

Date
Format	Used For	Description
d	Days	Displays the day as a number from 1 to 31
dd	Days	Displays the day as a number with a leading 0 if the number is less than 10
ddd	Weekdays	Displays a weekday name with 3 letters as Mon, Tue, etc
dddd	Weekdays	Displays the complete name of a week day as Monday, etc
M	Months	Displays the numeric month from 1 to 12
MM	Months	Displays the numeric month with a leading 0 if the number is less than 10
MMM	Months	Displays the short name of the month as Jan, Feb, Mar, etc
MMMM	Months	Displays the complete name of the month as January, etc
yy	Years	Displays two digits for the year as 00 for 2000 or 03 for 2003
yyyy	Years	Displays the numeric year with 4 digits

Besides these letters, an empty space and/or a special character should be used to separate the sections of the string. You should use an appropriate character as defined in the Regional Settings of the Control Panel:

Based on this, in US English, the character used to separate the date sections is the forward slash if you use a short date. In US English, the comma is used to separate the sections of a long date.

Time
Format	Used For	Description
h	Hour for 12-hour basis	Used to display the hour with one digit if the value is less than 10
hh	Hour for 12-hour basis	Used to display the hour with a leading 0 if the value is less than 10
H	Hour for 24-hour basis	Used to display the hour with one digit if the value is less than 10
HH	Hour for 24-hour basis	Used to display the hour with a leading 0 if the value is less than 10
m	Minute	Used to display the minute with one digit if the value is less than 10
mm	Minute	Used to display the minute with a leading 0 if the value is less than 10
t	AM/PM	Displays the letter A or P for the AM or PM section
tt	AM/PM	Displays the letters AM or PM for the last section

Besides the Format property, you can create a mask using the Mask field of the Properties window. Both allow you to use many other characters to create custom masks.