Answer: – Controls are object that are placed on form objects. Most applications written in VB use controls places on a form. Labels, command buttons and scroll bars are all controls. The toolbox gives a set of standard controls. Each type of control has properties related to its appearance and behavior. Like form properties, control property can set either at design time or at run time. There are number of controls available on tool box. But commonly used controls are label, text-box, and command button.
Label: – A label is a graphical control that is used to display text such as status messages and another program information. This text cannot be called directly. Common properties of label control are caption, alignment, word wrap, auto size etc.
Command button: – A command button which is also known as push button, is one of the most commonly used control in a user interface. It is used to begin, interrupt, or end a particular process. It is the appearance of the command button that determines whether it is pressed or released. It contains a label as caption which indicates the action to be performed. Access keys can be attached to the command button by placing an ampersand (&) sign before the character that we want to function as an access key in the caption property. Commonly used command button properties are caption, name, value etc.
Text box: – A text box control is used to obtain fill in the blank information from the user or to display information provided by the application. The user can change the information displayed in the text box. The commonly used properties are name, text, enabled, max length, multiline, scrollbar, password char, border style, mouse pointer etc.