You can implement different kinds of validation by using different validation controls. The following table lists the types of validation controls available and how you can use them.
Type of validation | Control to use | Description |
---|---|---|
Required entry | RequiredFieldValidator | Ensures that the user does not skip an entry. |
Comparison to a value (including database fields) | CompareValidator | Compares a user's entry against a constant value or a property value of another control using a comparison operator (less than, equal, greater than, and so on). To check against a database field, for the comparison value you specify an expression that gets the data to compare against. |
Range checking | RangeValidator | Checks that a user's entry is between specified lower and upper boundaries. You can check ranges within pairs of numbers, alphabetic characters, and dates. Boundaries can be expressed as constants or as values derived from another control. |
Pattern matching | RegularExpressionValidator | Checks that the entry matches a pattern defined by a regular expression. This type of validation allows you to check for predictable sequences of characters, such as those in social security numbers, e-mail addresses, telephone numbers, postal codes, and so on. |
User-defined | CustomValidator | Checks the user's entry using validation logic that you code yourself. This type of validation allows you to check for values derived at run time. |
You can attach more than one validation control to an input control. For example, you might specify that a control is both required and that it contain a specific range of values.
See Also