Regular expression validator not validating
There are four key properties to initialize for a Range Validator.
The Control To Validate property references the ID of the input control to check.
The associated control is set by right clicking on the validator and selecting Properties from the context menu. The rest of the validation controls provided by ASP.
In the Properties dialog box find the Control To Validate property and select First Name Text Box from the drop down list. We can set other properties, such as the Error Message property, and the final ASPX source code should look like the following. NET work in a similar fashion to what we've seen above. If the client's web browser is of executing client side Java Script, the first validation pass occurs on the client.
The Range Validator will first try to convert the values it is examining into the type specified.
As we will see later in the code-behind file, the Cancel Button will clear all of the fields on the form, and we do not want to validate any of the fields when the user presses this button. If any one of the validation controls on a form fails, the script cancels the postback operation and displays error messages on the form.
Notice in the following screen capture, we can see the Required Field Validator error message display on the form. The user does not wait on a server round trip to discover errors.
Drag one Text Box control and give it an ID of First Name Text Box, two Button controls (Submit Button and Cancel Button), and one Required Field Validator (First Name Required Field Validator). The following screen shows the form in action, and the user has pressed the Submit button without entering any text into the textbox. The Required Field Validator fails when the value in the associated control matches the value of the Initial Value property of the Required Field Validator.
This Required Field Validator forces the user to enter text into the control associated with the validator. If you want to make sure the user changes a default value placed into the control, set the control’s Text value and the Initial Value property of the Required Field Validator to the same value.
Html Controls; namespace Web Data Validation When the user clicks the Cancel button we clear the Text Box control and allow the user to start over.