Vb net textbox validating
Once it comes to serverside validation, it's your job to make sure that no sensitive code is executed unless you want it to.As you see, it's very simple - just check the Page. Try to run the website again, and notice how the text of the button is changed if you submit a valid form.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.This is very important, since this code WILL be reached if the clientside validation is not used, for some reason.I know that maybe this is because of the _Validating event (the event 'validates' the text in the textbox first) but what I want is for the addition to fire up instantly on record-viewing. By the way, here are the codes that I used: 'this is the validating event Private Sub txt Amount2_Validating(By Val sender As System. Cancel = True because what if I accidentally 'tab-focused' on a textbox but didn't want to input anything? Cancel = True End If End If End Sub 'and this is what I call the 'addition' event Private Sub txt Amount2_Text Changed(By Val sender As System. The above code checks whether numeric data is entered in the Credit text box control.The default event of the Text Box is the Text Changed Event.
Right now, the button does nothing, besides posting back if the page is valid.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.I use this formatting for six textboxes that have to have their values added. So what happens is after I typed in an amount and left the textbox, the amount (the text I inputted) becomes formatted, and the 'Total' (where the sum is displayed) is automatically updated (I did this using the _Text Changed Event).