Vb net validating event
NET controls is in the order in which they fire the Lost Focus and Validate events.VB6 controls fire the Validate event first and then the Lost Focus event; if the Validate sets Cancel=True, then the Lost Focus event is never fired.
Back Color = vb White End Sub Private Sub Text1_Validate(Cancel as Boolean) Cancel = (Text1. In some applications, however, the code in the Text1_Lost Focus method might depend on some variable that has been set in the Validate event.We recommend that you don’t set the Focus Event Support property to True unless really necessary, because this setting adds overhead to the standard event dispatching process and might cause other minor annoyances.To learn more about your VB6 applications, run VB6 Analyzer on your source code and send us the generated text file.You will receive a detailed report about your VB6 applications and how VB Migration Partner can help you to quickly and effectively migrate it to . For the sake of this example, you can ignore the labels.Figure 1 - These objects will determine if all our data is valid or not. Clear() 'Clear Text Box Name Valid = False 'Boolean = False Else Name Valid = True 'Everything Fine End If End Sub Easy one to start with. Focus() 'Set Focus To Text Box End If End Sub Private Sub txt Email_Lost Focus(sender As Object, e As System. Lost Focus Validate Email() 'Check Email Validity End Sub The expression may look horrible to the layman's eye, but look closer. To check if the user has entered an email that actually exists, you will have to find a different way such as to send a of some sorts.
Based on each of these variables' values, we will know if the data is correct or not. The Leave event fires when the control loses focus. As you can see, Regular Expressions are a vital tool to have at your disposal, so become good friends with them.
Text = "") End Sub Now consider the corresponding VB. If the end user clicks on a different control and Text1 contains an empty string, the Lost Focus event resets the background color to white, then the Validate event cancels the focus shift, and finally the Got Focus event changes the background color to yellow again. If this is the case, the converted code might fail or behave unexpectedly.
In such cases, you can force the controls in the support library to behave more closely to the original VB6 controls by setting the VB6Config.
The sequence is the same regardless of how the end user moves the input focus away from the control. NET controls fire these events in the same sequence only if end users move the input focus by means of the keyword; if they use the mouse, the control fires a Lost Focus event, then the Validating event, and – if the validation fails – another Got Focus event to let the application know that the focus is again on the control. NET programs created by VB Migration Partner follow the . In most cases, the fact that the Lost Focus event fires before the Validate event doesn’t affect the application negatively.
For example, consider the following VB6 code: Private Sub Text1_Got Focus() Text1.
Sometimes people are just trying to be funny, or they are literally trying to break your program. If the data is indeed only alphabetic letters (no symbols, no numbers or any other punctuation characters) the test succeeds and stores True inside the Name Valid variable. This is because it becomes more legible than just a normal set of numbers.