introduction to windows piprogramm ing · standard controls c# programming: from problem analysis...

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Copyright © 2007Robinson College of Business, Georgia State UniversityDavid S. McDonald Director of Emerging TechnologiesTel: 404-413-7368; e-mail: [email protected]

8 Introduction to Windows P i8 Programming

David McDonald, Ph.D.Director of Emerging Technologies

C# Programming: From Problem Analysis to Program Design 2nd Edition

Chapter Objectives

Learn about graphical user interfaces

Become aware of some elements of good design

Use C# and Visual Studio to create Wi d b d li ti

C# Programming: From Problem Analysis to Program Design

Windows-based applications

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Chapter Objectives (continued)

Create Windows forms and be able to h fchange form properties

Add control objects such as buttons, labels, and text boxes to a form

W k th h i l


Work through a programming example that illustrates the chapter’s concepts

Graphical User Interfaces Windows applications also look different from console applicationsInterface: front end of a program√Visual image you see when you run a

program Graphical user interface (GUI) includes:√


√Menus√Text in many different colors and sizes√Other controls (pictures, buttons, etc.)

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Windows ApplicationsReference and import System.Windows.Forms namespace Class heading definition√Includes not only the class name, but a

colon followed by another class name • Derived class (first class)• Base class (second class)


Base class (second class)• public class Form1 : Form

Derived classes inherit from base class

Windows Applications (continued)Text√ A property for setting/getting title bar caption√ Can be used in constructor√ Can be used in constructor

Windows forms/controls offer many properties including Text, Color, Font, and LocationExecution begins in Main( ) method√Main( ) is located in Program.cs file for the application√ Call to Run( ) method places application in process


√ ( ) p pp ploop

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// Windows0.cs Author: McDonaldusing System.Windows.Forms; // Line 1namespace Windows0{

public class Form1 : Form // Line 2{

public Form1( ) // Line 3

New namespace referenced

C t t

Base class

public Form1( ) // Line 3{

Text = "Simple Windows Application"; // Line 4}static void Main( )

{Form1 winForm = new Form1( ); // Line 5

Constructor

Sets title bar caption


( );Application.Run(winForm); // Line 6

}}

}Starts

process loop

Windows Application (continued)

Output generated

from Windows0 application


Figure 8-1 Windows-based form

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Elements of Good Design Appearance matters √Human-computer interaction (HCI) p ( )

researchDesign considerations√Consistency √Alignment


√Avoid Clutter √Color √Target Audience

Use Visual Studio to Create Windows-based Applications

Windows Application

templateBrowse

to location to store

Select File New

Project


your workName

Figure 8-2 Visual Studio New Windows application

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Windows-based Applications

PropertiesWindow

Switch between

Design and Code view using View

menu


Design ViewToolbox

Figure 8-3 Initial design screen

Windows-based Applications

PropertiesAuto-hide

pushpin

Dynamic Help

Solution Explorer


Figure 8-4 Dockable windows

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Windows Forms

Extensive collection of Control classes Top level window for an application isTop-level window for an application is called a Form Each control has large collection of properties and methods √Select property from an alphabetized list √ p p y p

(Properties window)√Change property by clicking in the box

and selecting or typing the new entry

Windows Form Properties

Alphabetical

Events

Properties Property value

Categorized


Figure 8-5 Properties window

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Windows Form Properties (continued)


Windows Form EventsAdd code to respond to events, like button clicks

From the Properties window, select the lightening bolt (Events)

√ Double-click on the event name to generate code

• Registers the event as being of interest

• Adds a heading for event-handler method


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Windows Form Properties

Events button

selected


Figure 8-6 Form1 events

Windows Form – Closing Event

Code automatically added to register eventthis.Closing += new

S t C tM d l C lE tH dlSystem.ComponentModel.CancelEventHandler(this.Form1_Closing);

Code automatically added for method headingprivate void Form1_Closing(object sender,

System.ComponentModel.CancelEventArgs e){}


}You add statement to event-handler method bodyMessageBox.Show("Hope you are having fun!");

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Simple Windows Application New with Visual Studio 2005, the IDE separates the source code into three separate filessource code into three separate files√ Form1.cs: Normally this is the only one you edit√ Form1.Designer.cs: Holds the auto-generated

code√ Program.cs: Contains the Main( ) method, where

execution always begins


Form1.cs and Form1.Designer.cs both include partial class definitions for the Form1 class

Windows Form Events (continued)

Expand Form1.cs node to reveal the Form1.Designer.cs

file


Figure 8-7 Solution Explorer window

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Controls Controls are all classes

√Button, Label, TextBox, ComboBox, MainMenu, ListBox, CheckBox, RadioButton, and MonthCalendar

Each comes with its own predefined properties and methods

Each fires events


Each fires events

Each is derived from the System.Windows.Forms.Control class

Controls (continued)

DotsDots indicate

other classes

are derived from the

class


Figure 8-9 Control class hierarchy

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Standard Controls


Figure 8-10 Windows Forms controls

Controls (continued)Two procedures to place controls

√ From Toolbox, double-click on control or drag and√ From Toolbox, double click on control or drag and drop

Move, resize, and delete controls

Format controls

√ Align controls


√Make same size

√ Horizontal and vertical spacing

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Properties of the Control Class


Methods of the Control Class


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Controls


Figure 8-11 GUI controls

Label Objects

Provides descriptive text or labels for other controlsInstantiate objectInstantiate object

Label labelName = new Label( );Add control to Form

this.Controls.Add(labelName);Set property values (some from Control class)√ Text; TextAlign; Font; Location


√ Text; TextAlign; Font; Location

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Creating a TaxApp


Properties set for the Form container

Creating a TaxApp Form

Add Label

objects to Form

object, then

format


Figure 8-12 Formatting Label objects

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Adding Labels to TaxApp Form

Add Label objects, then set their properties using thetheir properties using the

Properties window (View Properties window)


TextBox ObjectsUsed to enter data or display text during run time √ Used for both input and output

I t ti t bj tInstantiate objectTextBox textBoxName = new TextBox( );

Add control to Form this.Controls.Add(TextBoxName);

Interesting properties√MultiLine, ScollBars, MaxLength, PasswordChar,


CharacterCasing

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TextBox Objects (continued)

C# Programming: From Problem Analysis to Program Design 33

Adding TextBox Objects to TaxApp Form

Add TextBox objects, then set their property

values


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ButtonEnables user to click button to perform task

√ If button has event-handler method and is registered as an event to which your program is planning toas an event to which your program is planning to respond, event-handler method is called automatically when button clicked

Button object’s properties, methods, and events

√ Inherits from Control (Table 8-2 & 8-3, slides 25 & 26)


• Text, Enabled, Focused, TabIndex

Adding Button Objects to TaxApp Form

Add Button objects, then set their property

values


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