If you're talking about VB with MVC, you can just use a Regular Expression Attribute on your model, for example.
Implicit validation occurs when Auto Validate for the form is set to Enable Prevent Focus Change (the default) or Enable Allow Focus Change. But each control has a Validating and Validated event with a Console. Here's a partial snippet: Private Sub Text Box1_Validating( By Val sender As Object, By Val e As System. In the first article, I noted that you can set ...... When Auto Validate is set to Disable, calling Validate does nothing, even though it might appear to 'work'.--------Click Here to display the illustration--------In this case, there are two ways to trigger the execution of the Validating and Validated events.
Since the article above covers that, in this article, assume that Auto Validate for the form is set to Disable so Explict validation will be required. Writeline statements to confirm what is actually happening in the code. The first is to call Validate from the event subroutine handling the event.
It's an old fashioned debugging technique, but it really helps me in this particular case. A call to Validate can be triggered by code elsewhere, but it still doesn't trigger the Validating and Validated events as shown below.--------Click Here to display the illustration--------The second is to call Validate from a container control where the controls that you want validated are child controls.
In this simple example, the only candidate is the main form. To illustrate the principal, I've coded a call to the Validate method from the Click event of the form.--------Click Here to display the illustration--------(Keep in mind that this only happens when Auto Validate is Disable.)The other Validate overload passes a boolean. NET whether to check the current value of the Auto Validate property. Passing False gives the same result that you get with no parameter at all and results in the Validating and Validated events being triggered.