When the combobox text is "- Select a City -", the validator detects an error and displays the message "You must select a city!": When the combobox text is set to a city, the validator accepts the selection: Validates to make sure the user entered a value. Forms; namespace Windows Forms Application1 Public Class Form1 Private Sub Text Box1_Key Press(By Val sender As Object, By Val e As System. Handled = True End If End Sub Private Sub Text Box1_Text Changed(By Val sender As System.
This can be done when the form loads, or with the contents of the List Box or Combo Box are changed based on another selection (see our tip on Cascading Combo Boxes/List Boxes). NET is an update to Visual Basic that targets Microsofts . It is the most productive tool for rapidly creating a wide range of Windows, Web, Mobile, and Office applications built on the . The Visual Basic language is designed to be human readable and accessible to everyone from novice programmers to advanced system architects. NET Framework, which guarantees that programs written in Visual Basic run with unsurpassed scalability and reliability. NET languages such as Visual C#, Visual J#, or Visual C . NET in a simplified manner rather than in a complex way. NET has a lot of similarities to Visual Basic but also some differences. NET is an object-oriented language, which supports the abstraction, encapsulation, inheritance, and polymorphism features. Net programmers with the ability to create fully object oriented programs (OOPs), just like the ones created using Java, C# or C . Net will interoperate seamlessly with programs written in any other . I hope this site will help you to acquire the skills and knowledge necessary to develop various types of applications in VB. NET Framework that makes it easier and faster to program than ever before. It includes a powerful set of libraries called the .In this example, we demonstrate how to activate such validation.