Masks
The MaskedTextBox supports a set of built-in masks.
Mask Rules
- If any of the following masks accepts spaces, set the promptPlaceholder to a character that is not allowed by the mask.
- To escape a mask rule, use the slash (
\
) character. An escaped rule turns into a literal.
The supported mask rules are:
0
—Requires a digit (0-9).9
—Requires a digit (0-9) or a space.#
—Requires a digit (0-9), space, plus (+), or minus (-) sign.L
—Requires a letter (a-Z).?
—Requires a letter (a-Z) or a space.A
—Requires an alphanumeric (0-9, a-Z).a
—Requires an alphanumeric (0-9, a-Z) or a space.&
—Requires a character (excluding space).C
—Requires a character or a space.
You can also define custom rules by using the rules property.
Apart from the built-in and custom rules, you can also use static symbols in the mask pattern that are also known as literals. In the masked value, a literal is always rendered on the same position as the position where it is defined in the mask
property.
The following example demonstrates how to use the digit-requiring mask (0
) and the literal (-
) of the MaskedTextBox.
The following example demonstrates how to extend the available mask rules.
Masks on Input Values or Focus
By default, the MaskedTextBox always renders a mask. To display the mask only when the input contains a value or is focused, use the maskOnFocus option. maskOnFocus
is particularly useful in combination with floating labels.