understand how to create new controls and extend existing controls 98-362 windows development...

Understand How to Create New Controls and Extend Existing Controls

98-362 Windows Development Fundamentals

LESSON 2.3A


LESSON 2.3A

Lesson Overview

How can a developer design and implement custom GUI controls?

In this lesson, you will learn about: Different types of custom controls Determining which type of custom control to use to fit a situation Creating user controls


LESSON 2.3A

Anticipatory Set

With a partner, create a list of controls that are often used together in a Windows Form, or sets of controls that are commonly used on multiple forms.


LESSON 2.3A

Custom Control Types

User control (or composite control) — A collection of Windows Forms controls encapsulated into one container — Inherits from the UserControl classInherited control (or extended control) — A control that derives from an existing Windows Forms control, such as a Button, TextBox, ComboBox, or RadioButton

— Retains all the functionality of the base control from which it inheritsCustom control — This term can refer to user controls or inherited controls, but it sometimes refers

to controls that inherit from the Control class. — Allows developers to create a control from scratch — Requires much more work, and also requires knowledge of the Win32

application programming interface (API)


LESSON 2.3A

Create a user control if…

You wish to combine the functionality—and graphical user interface (GUI)—of multiple existing Windows Forms controls.

Examples: A single control that includes a TextBox and the Label that identifies it. A single control that includes buttons for OK and Cancel.


LESSON 2.3A

Inherit from an existing control if…

The desired functionality is similar to an existing control.

Examples: — A TextBox that converts inputted text to a numeric data type. — A TextBox that formats numbers as currency.

You wish to design a new GUI for an existing control.

Example: — A Button with an elliptical interface instead of a rectangular interface.

Inherited controls provide an efficient way to reuse common GUI elements.


LESSON 2.3A

Inherit from an existing control if…(continued)

You wish to combine the functionality—and GUI—of multiple existing Windows Forms controls.

Examples: — A single control that includes a TextBox and the Label that identifies it — A single control that includes buttons for OK and Cancel.

Inherited controls provide an efficient way to reuse common GUI elements.


LESSON 2.3A

Inherit from the Control class if…

You wish to implement functionality that is not available in existing controls.

Example: — A control that displays a three-dimensional model that the user can rotate.


LESSON 2.3A

Creating a User Control

Follow along in Microsoft Visual Studio®.

Create a LabeledTextBox—a control that combines a TextBox with its associated Label.


LESSON 2.3A

Lesson Review

List the different types of custom controls.

Explain the uses and advantages of each type of control.


LESSON 2.3A

Lesson Review

Create a user control that combines two buttons, OK and Cancel. Add the control to two different forms within your project.

understand how to create new controls and extend existing controls 98-362 windows development...

Documents