Microsoft Visual Basic 2010 Step by Step eBook

412 Part III Designing the User Interface

Chapter 16 Quick Reference

To Do This

Inherit an existing

form’s interface

and functionality

Click the Add New Item command on the Project menu, click the Inherited

Form template, specify a name for the inherited form, and then click Add.

Use the Inheritance Picker to select the form you want to inherit, and then

click OK.

Note that to be eligible for inheritance, base forms must be compiled as

.exe or .dll files. If you want to inherit a form that isn’t a component in the

current project, the form must be compiled as a .dll file.

Customize an

inherited form

Add Toolbox controls to the form, and set property settings. Note that

you won’t be able to set the properties of inherited objects on the form.

These objects are identified by small icons and are inactive.

Create your own

base classes

Click the Add Class command on the Project menu, specify the class name,

and then click Add. Define the class in a class module by using program code.

Hide declared

variables in a class

Use the Private keyword to hide class variables from other programmers

who examine your class. For example:

Private Name1 As String

Create a new

property in the class

Define a public property procedure in the class. For example:

Public Property FirstName() As String

Get

Return Name1

End Get

Set(ByVal value As String)

Name1 = value

End Set

End Property

Note that the first line shown in this example (containing the Property

statement) is all that you may need to enter if you are creating a new property

with few custom settings. In other words, Visual Studio 2010 automatically

recognizes the Property keyword when you enter it and uses the new

auto-implemented properties feature to create a basic property definition for

you. However, in this chapter, I have shown the complete Get and Set syntax

because it is useful in many real-world coding scenarios.

Create a new method

in the class

Define a Sub or Function procedure in the class. For example:

Public Function Age(ByVal Birthday As Date) As Integer

Return Int(Now.Subtract(Birthday).Days / 365.25)

End Function

Declare an object

variable to use the

class

Use the Dim and New keywords, a variable name, and the user-defined class

in a program statement. For example:

Dim Employee As New Person