ASP.NET Web Forms Web Forms Server Controls Web Forms Validation
You can validate a user’s entry against a specific data type to be sure that what the user has entered is a number, or a date, and so on. For example, if you want to collect birth date information on a user registration page, you can use a CompareValidator control to make sure that the date is in a recognized format before it is submitted to your database.
- Add a CompareValidator control to the page and set the following properties:
| Property |
Setting |
| ControlToValidate |
The ID of the input control that the validation control will evaluate. |
| Display |
The display behavior for the specified validation control. |
| ErrorMessage |
The error message to display in the ValidationSummary control if validation fails. |
| Text |
The error message to display in the validation control when validation fails. |
- Set the data type to compare to by setting the following properties:
| Property |
Setting |
| Type |
The data type to check against. The type is specified using the ValidationDataType enumeration, which allows you to use the type names String, Integer, Double, Date, or Currency. |
| Operator |
Set to DataTypeCheck. |
- In your Web Forms code, check for validity. For details, see Testing Validity Programmatically.
NOTE: If the user leaves a control blank, the control passes the comparison validation. To force the user to enter a value, add a RequiredFieldValidator as well. For details, see Validating Required Entries.
Validating Against a Specific Value Validating Against Values in a Database CompareValidator Control CompareValidator Class Data Entry Validation ( Client-Side )