Validating textbox in vb

18-Aug-2020 22:26

Let's give it a try, and add a Required Field Validator to our page.We will also add a Text Box to validate, as well as a button to submit the form with.This tutorial describe how to validate an email address using regex in visual basic NET to My Sql Database Tic Tac Toe - Visual Basic . NET Placing Controls on Form Hangman Tutorial - Page 1 - Visual Basic .In the real world, you build an application that stores customers email address in your database. Text) = True Then Msg Box("Email is Valid") 'proceed and save email Else Msg Box("Email is not Valid") End If End Sub Check if internet connection available in Visual Basic . NETDisplay an Image in Picture Box in Runtime - Visual Basic . NETCalculating Services Provided and Discount - Visual Basic . I have a form w/ a textbox and Cancel button on it. When I click on the cancel button it doesn't even get to the cancel.click event until AFTER it has done the validating. As far as the original validation issue, I started a new project (VB2005) and tried your approach It works except that pressing the Esc key still causes the validation event to fire. According to the documentation: "The cancel button for a form is the button control that is clicked whenever the user presses the ESC key." Which says to me the behavior s/b the same! Validating If Not mbln Cancel Then Dim dte Date As Date Time If Date Time. Also note that the "trick" to closing the form is not keeping a seperate "canceling" flag, but to put "e.cancel=False" in the forms closing event.I have a routine to handle textbox.validating, and I have the form setup so the Cancel button is the Cancel button. I am going to start a new thread - calling it a bug and see what happens. Down (Down Arrow) and some how (and I never figured this one out) the next control in the tab order, regardless of the Tab Stop property, got focus. Causes Validation = False Public Class Form1 Private mbln Cancel As Boolean Private Sub Text Box1_Validating(By Val sender As Object, By Val e As System. -- Terry "Al Reid" wrote: Terry, I tried the same scenario in VB6 and found that it works the way one would expect AND there is no need for the m Cancel flag either.

validating textbox in vb-21

Text = "" Then Msg Box "Please enter " & Mid(Frm For Check.

In a perfect world, your code would run correctly every time.

You will first see the programming you can use to handle errors, and then you will see how to use validation techniques to prevent bad data from being entered into your application in the first place.

One, remove the "control Box" from the form, so the user cant close it that way. in the btn Cancel_Click event: Removehandeler Text Box1.validating, Addressof Text Box1_Validating -- Terry That doesn't work either, at least not for VB2005. Then in the btn Cancel_click event, either set a module level variable like m Canceling to True and then in the validating event ... I've been fighting the same problem for some time now. I think that the only way to do this is to grab the mouse coordinates in the validating event, do a Window From Point API call, then compare the returned HWND to the Cancel Button's Handle. I also got the Window From Point approach working as well. The following code works as you might hope: Public Class Form1 Private m Canceling As Boolean = False Private Sub Button1_Click(By Val sender As System. Private Sub Text Box1_Validating(By Val sender As Object, By Val e As System. As far as the 'gun', it may be better to write a console app. -- Terry "Al Reid" wrote: Terry, I don't do anything with the barcode data in the Key Press event. I guess I could inspect the data in the Key Down event to see if there is a difference. news:78**********************************@microsof .. I am new to VB comming from VB6, but that was also the case in VB6. I added the code to handle the esc key per the "bug" thread and it works.

Then in the btn Cancel_click event, either set a module level variable like m Canceling to True and then in the validating event ... I've been fighting the same problem for some time now. I think that the only way to do this is to grab the mouse coordinates in the validating event, do a Window From Point API call, then compare the returned HWND to the Cancel Button's Handle. Close() End Sub Private Sub Text Box1_Validating(By Val sender As Object, By Val e As System. When you click on the button the validating event fires. If the handle matched then immediately exit the Validating event without setting e. -- Al Reid I had tried all of that, *BUT*, I had neglected to set the button's Causes Validation to False. I just don't know what key code combination could direct focus to a text box control that should never receive focus since the Tab Stop property is false and there is no other code that sets focus to the textbox. Also in the docs on Key Down there is a mention of "Is Input Key" which I will have to look into. However, after I removed the "canceling" flag and added the "e.cancel=False" to the form's Form Closing event, I once again see the validation when clicking on the cancel button, but the form then closes after displaying the validation error. -- Al Reid "Terry" Hi Al, Don't know if you have been following the thread I started about the escape key "bug", but if you search this community for "Cancel Button vs Escape Key", you can see the result including the work around for the escape key.

Text = "" Then Msg Box "Please enter " & Mid(Frm For Check. In a perfect world, your code would run correctly every time. You will first see the programming you can use to handle errors, and then you will see how to use validation techniques to prevent bad data from being entered into your application in the first place.One, remove the "control Box" from the form, so the user cant close it that way. in the btn Cancel_Click event: Removehandeler Text Box1.validating, Addressof Text Box1_Validating -- Terry That doesn't work either, at least not for VB2005. Then in the btn Cancel_click event, either set a module level variable like m Canceling to True and then in the validating event ... I've been fighting the same problem for some time now. I think that the only way to do this is to grab the mouse coordinates in the validating event, do a Window From Point API call, then compare the returned HWND to the Cancel Button's Handle. I also got the Window From Point approach working as well. The following code works as you might hope: Public Class Form1 Private m Canceling As Boolean = False Private Sub Button1_Click(By Val sender As System. Private Sub Text Box1_Validating(By Val sender As Object, By Val e As System. As far as the 'gun', it may be better to write a console app. -- Terry "Al Reid" wrote: Terry, I don't do anything with the barcode data in the Key Press event. I guess I could inspect the data in the Key Down event to see if there is a difference. news:78**********************************@microsof .. I am new to VB comming from VB6, but that was also the case in VB6. I added the code to handle the esc key per the "bug" thread and it works.Then in the btn Cancel_click event, either set a module level variable like m Canceling to True and then in the validating event ... I've been fighting the same problem for some time now. I think that the only way to do this is to grab the mouse coordinates in the validating event, do a Window From Point API call, then compare the returned HWND to the Cancel Button's Handle. Close() End Sub Private Sub Text Box1_Validating(By Val sender As Object, By Val e As System. When you click on the button the validating event fires. If the handle matched then immediately exit the Validating event without setting e. -- Al Reid I had tried all of that, *BUT*, I had neglected to set the button's Causes Validation to False. I just don't know what key code combination could direct focus to a text box control that should never receive focus since the Tab Stop property is false and there is no other code that sets focus to the textbox. Also in the docs on Key Down there is a mention of "Is Input Key" which I will have to look into. However, after I removed the "canceling" flag and added the "e.cancel=False" to the form's Form Closing event, I once again see the validation when clicking on the cancel button, but the form then closes after displaying the validation error. -- Al Reid "Terry" Hi Al, Don't know if you have been following the thread I started about the escape key "bug", but if you search this community for "Cancel Button vs Escape Key", you can see the result including the work around for the escape key.We will change this by adding an onclick event to it: As you will notice, we check whether or not the page is valid, before we do anything.