GUI Controls, Events, MsgBox & Conditional Statements

• A label is a graphical control to display text.
• A EditText control is used to display or accept as input a single line of text.
• A Button control represents a standard Windows button, used to generate a Click event by providing a handler for the Click event.
• Events are signals that inform an application that something important has occurred.

Events

• When a user clicks a control on a form, the form raises a Click event
• Events call a procedure that handles the event.
• Events allow separate tasks to communicate.

MsgBox

• MsgBox (message box) is a dialog box used to display a piece of information to the user.
• The user cannot type anything in the dialog box, as opposed to a regular form.

Conditional statements

• Conditional Statements are used to make decisions based on conditions.
• Conditional statements execute sequentially when there is no condition.
• If there is a condition for a block of statements, the execution flow may change based on the result of the condition, called decision making.
• Basic Syntax: If logical_expression Then, One or more statements, Else, One or more statements, End If

RadioButton

• The RadioButton control is used to provide a set of mutually exclusive options.
• The user can select one radio button in a group.
• If more than one group of radio buttons are present, they should be placed in different container controls like a Panel control.
• Basic syntax: Sub RadioButton1_CheckedChange(Checked As Boolean), One or more statements, End Sub
• A Boolean is a logical data type that can have only the values true or false.

RadioButtons

• To use multiple sets or groups of RadioButtons, a Panel must be placed to hold the other set of RadioButtons.