ASP.NET RequiredFieldValidator Control
 Complete Validation Control Reference
Definition and Usage
The RequiredFieldValidator control is used to make an input control a
required field.
With this control, the validation fails if the input value does not change from its
initial value. By default, the initial value is an empty string
("").
Note: Leading and trailing spaces of the input value are
removed before validation.
Note: The InitialValue property does not set the default value for the
input control. It indicates the value that you do not want the user to
enter in the input control.
Properties
| Property |
Description |
| BackColor |
The background color of the RequiredFieldValidator control |
| ControlToValidate |
The id of the control to validate |
| Display |
The display behavior for the validation control. Legal
values are:
- None (the control is not displayed. Used to
show the error message only in the ValidationSummary control)
- Static (the control displays an error message if validation
fails. Space is reserved on the page for the message even if
the input passes validation.
- Dynamic (the control displays an error message if
validation fails. Space is not reserved on
the page for the message if the input passes validation
|
| EnableClientScript |
A Boolean value that specifies whether client-side
validation is enabled or not |
| Enabled |
A Boolean value that specifies whether the validation
control is enabled or not |
| ErrorMessage |
The text to display in the ValidationSummary control when
validation fails. Note: This text will also be displayed in the
validation control if the Text property is not set |
| ForeColor |
The foreground color of the control |
| id |
A unique id for the control |
| InitialValue |
Specifies the starting value of the input control. Default value is "" |
| IsValid |
A Boolean value that indicates whether the control
specified by ControlToValidate is determined to be valid |
| runat |
Specifies that the control is a server control. Must
be set to "server" |
| Text |
The message to display when validation fails |
Examples
RequiredFieldValidator
In this example we declare two TextBox controls, one Button control, and one RequiredFieldValidator control in an .aspx file. It
shows how to use the RequiredFieldValidator control to make the "txt_name"
textbox a required field.
Complete Validation Control Reference
 |
W3Schools' Online Certification Program
The perfect solution for professionals who need to balance work, family, and career building.
More than 4000 certificates already issued!
|
The HTML Certificate documents your knowledge of HTML, XHTML, and CSS.
The JavaScript Certificate documents your knowledge of JavaScript and HTML DOM.
The XML Certificate documents your knowledge of XML, XML DOM and XSLT.
The ASP Certificate documents your knowledge of ASP, SQL, and ADO.
The PHP Certificate documents your knowledge of PHP and SQL (MySQL).
| 
