Chapter 13. Graphical User Interface Concepts: Part 1

2007 Dr. Natheer Khasawneh.

Chapter 13. Graphical User Interface Concepts: Part 1


Simple Windows Application

• In Visual Studio 2005, if you choose– File->New Project

– Windows Application

• The following will be generated for you– Form1.cs

– Form1.Designer.cs

– Program.cs

• Lets look at them


Program.csusing System;using System.Collections.Generic;using System.Windows.Forms;

namespace SimpleApplication{ static class Program { /// <summary> /// The main entry point for the application. /// </summary> [STAThread] static void Main() { Application.EnableVisualStyles(); Application.SetCompatibleTextRenderingDefault(false); Application.Run(new Form1()); } }}

What is this?


Form1.csusing System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Drawing;using System.Text;using System.Windows.Forms;

namespace SimpleApplication{ public partial class Form1 : Form { public Form1() { InitializeComponent(); } }}


Form1.Designer.csnamespace SimpleApplication{ partial class Form1 { /// <summary> /// Required designer variable. /// </summary> private System.ComponentModel.IContainer components = null;

/// <summary> /// Clean up any resources being used. /// </summary> /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param> protected override void Dispose(bool disposing) { if (disposing && (components != null)) { components.Dispose(); } base.Dispose(disposing); } #region Windows Form Designer generated code /// <summary> /// Required method for Designer support - do not modify /// the contents of this method with the code editor. /// </summary> private void InitializeComponent() { this.components = new System.ComponentModel.Container(); this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font; this.Text = "Form1"; } #endregion }}


Application Class

• The System.Windows.Forms.Application class wraps the basic functionality to start a .NET application.

• This class has methods to start and stop applications and their threads, and to process Windows Messages:– DoEvents()– Exit()– ExitThread()– Run()

• The class also has events and properties to synchronize execution.


Application Class

• Run static method begins running a standard application message loop on the current thread.

• Below is the overload list:


Partial Class

• A partial class, or partial type, is a feature of C# programming languages in which the declaration of a class or a struct or an interface may be split across multiple source-code files.

• Purpose– Very large classes

– Separation of concerns

– Multiple developer


Windows Forms

• Forms are contained within a namespace called System.Windows.Forms that contains around 200 classes, 100 enumeration, more than 40 delegates, 7 interfaces, and 4 structures.

• The inheritance lineage isObject ->

MarshallByRefObject -> Component->

Control-> ScrollableControl->

Form


Windows FormsForm Properties and Events

Description / Delegate and Event Arguments

Common Properties

AcceptButton Which button will be clicked when Enter is pressed.

AutoScroll Whether scrollbars appear when needed (if data fills more than one screen).

CancelButton Button that is clicked when the Escape key is pressed.

FormBorderStyle Border of the form (e.g., none, single, 3D, sizable).

Font Font of text displayed on the form, as well as the default font of controls added to the form.

Text Text in the form’s title bar.

Common Methods

Close Closes form and releases all resources. A closed form cannot be reopened.

Hide Hides form (does not release resources).

Show Displays a hidden form.

Common Events (Delegate EventHandler, event arguments EventArgs)

Load Occurs before a form is shown. This event is the default when the form is double-clicked in the Visual Studio .NET designer.

Fig. 13.4 Common Form properties and events.


Form

• Form class represents window, provides appropriate services– properties: Size, Location, Controls, ShowInTaskbar– methods: Show, Close, SetDesktopLocation– events: Load, Click, Closing

• Common to derive from Form to create custom form

class MyForm : Form{ public MyForm() { this.ShowInTaskbar = false; this.Location = new Point(10, 10); this.Size = new Size(100, 100); }}

define custom form

set properties


Form border

• Forms can look like windows, dialogs, or tools– controlled using FormBorderStyle property

– set ShowInTaskbar property to false for tool windows

– window border styles show the icon from the Icon property


Form properties

• Form has many properties– used to customize appearance and behavior

public class Form : ContainerControl{ public IButtonControl AcceptButton { get; set; } public IButtonControl CancelButton { get; set; } public bool HelpButton { get; set; }

public Icon Icon { get; set; } public String Text { get; set; }

public Size MaximumSize { get; set; } public Size MinimumSize { get; set; }

public MainMenu Menu { get; set; }

public bool ShowInTaskbar { get; set; }

public FormBorderStyle FormBorderStyle { get; set; } ...}

properties


SimpleForm.cs

using System;using System.Windows.Forms;

class SimpleForm{ static void Main() { Form f1 = new Form(); f1.Text = "My Simple Form"; Application.Run(f1); }}

csc /t:winexe SimpleForm.cs


SimpleForm2.cs

using System;using System.Windows.Forms;

class SimpleForm{ static void Main() { Form f1 = new Form(); f1.Text = "My Simple Form2"; f1.Show(); }}

What is the output?


SimpleForm3.csusing System.Threading;using System.Windows.Forms;

class SimpleForm{ static void Main() { Form f1 = new Form(); f1.Text = "My Simple Form3"; f1.Show(); f1.Text = "Time to sleep"; //Let the process go to sleep for 1000 ms (pause) Thread.Sleep(3000); f1.Text = "Time to wake up !"; //Let the process go to sleep for 1000 ms (pause) Thread.Sleep(1000); }}

What is the output?


SimpleForm4.cs

using System.Threading;using System.Windows.Forms;

class SimpleForm{ public static void Main() { Form f1 = new Form(); f1.Text = "What is wrong with this?"; f1.Visible = true; Thread.Sleep(3000); f1.Visible = false; Thread.Sleep(3000); f1.Text = "Coming back to live"; f1.Visible = true; Thread.Sleep(3000); Application.Run(); f1.Text = "After Application.Run is called"; }}

What is the output?


SimpleForm5.cs


class SimpleForm{ public static void Main() { Form f1 = new Form(); f1.Text = "What is wrong with this?"; f1.Visible = true; Thread.Sleep(3000); f1.Visible = false; Thread.Sleep(3000); f1.Text = "Coming back to live"; f1.Visible = true; Thread.Sleep(3000); Application.Run(f1); Thread.Sleep(3000); f1.Text = "After Application.Run is called"; }}

What is the output?


SimpleForm6.cs


class SimpleForm{ public static void Main() { Form f1 = new Form(); f1.Text = "How are you all doing?"; f1.Visible = true; Thread.Sleep(3000); f1.Text = "And How is your Baba?"; Application.Run(f1); Thread.Sleep(3000); f1.Text = "After Application.Run is called"; MessageBox.Show("And your Daddy too?"); }}

What is the output?


Conclusion

• Main creates the form and displays it.• The form is given to Application.Run where it

continues to exist.• The form takes control of execution until the form

is dismissed.• When the form is dismissed, presumably, the

Application.Run method continues (err, ends).• The Application.Run method returns control to

Main, which then calls the MessageBox.Show method.

• The application ends after the MessageBox is dismissed


SimpleForm7.cs


class SimpleForm{ public static void Main() { Form f0 = new Form(); f0.Text = "How are you?"; Form f1 = new Form(); f1.Text = "How is C#?"; Form f2 = new Form(); f2.Text = "How is C++"; f0.Show(); f2.Show(); Application.Run(f1); MessageBox.Show("Where are we?"); f2.Text = "F2, after Application.Run is called"; Thread.Sleep(3000); }}

Take Home

Bring back your description

Quiz


Not Very Simple Windows Application!

• Drag and drop textbox and button from the toolbox into the Form

• Lets see what happened to our three files.• Program.cs Form1.cs Form1.Designer.cs


Program.csusing System;using System.Collections.Generic;using System.Windows.Forms;

namespace SimpleApplication{ static class Program { /// <summary> /// The main entry point for the application. /// </summary> [STAThread] static void Main() { Application.EnableVisualStyles(); Application.SetCompatibleTextRenderingDefault(false); Application.Run(new Form1()); } }}

NO CHANGES!



namespace SimpleApplication{ public partial class Form1 : Form { public Form1() { InitializeComponent(); } }}

NO CHANGES!


Form1.Designer.csnamespace SimpleApplication{ partial class Form1 {//SAME AS BEFORE CODE OMMITED FOR SPACE private System.Windows.Forms.TextBox textBox1; private System.Windows.Forms.Button button1; private void InitializeComponent() { this.textBox1 = new System.Windows.Forms.TextBox(); this.button1 = new System.Windows.Forms.Button(); this.SuspendLayout(); // textBox1 this.textBox1.Location = new System.Drawing.Point(72, 24); this.textBox1.Name = "textBox1"; this.textBox1.Size = new System.Drawing.Size(100, 20); this.textBox1.TabIndex = 0; // button1 this.button1.Location = new System.Drawing.Point(82, 59); this.button1.Name = "button1"; this.button1.Size = new System.Drawing.Size(75, 23); this.button1.TabIndex = 1; this.button1.Text = "button1"; this.button1.UseVisualStyleBackColor = true; // Form1 this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F); this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font; this.ClientSize = new System.Drawing.Size(246, 109); this.Controls.Add(this.button1); this.Controls.Add(this.textBox1); this.Name = "Form1"; this.Text = "Form1"; this.ResumeLayout(false); this.PerformLayout();} #endregion }}

We have two new fields

The fields properties are initialized

The fields are attached to the Form


Not Simple Windows Application!

• Lets say I want to find the square of the number entered

• Double click on the button, and suddenly Form1.cs is opened for me and the following code is displayed for me.



namespace SimpleApplication{ public partial class Form1 : Form { public Form1() { InitializeComponent(); }

private void button1_Click(object sender, EventArgs e) { int x = int.Parse(textBox1.Text);

x = x*x; MessageBox.Show(x.ToString()); } }}

This method is written for me

I wrote this code


Form1.Designer.cs

namespace SimpleApplication{ partial class Form1 {//SAME AS BEFORE CODE OMMITED FOR SPACE//THE BUTTON1 IS THE PART THAT CHANGES // button1 // this.button1.Location = new System.Drawing.Point(82, 59); this.button1.Name = "button1"; this.button1.Size = new System.Drawing.Size(75, 23); this.button1.TabIndex = 1; this.button1.Text = "button1"; this.button1.UseVisualStyleBackColor = true; this.button1.Click += new System.EventHandler(this.button1_Click); }}

controlEvent Event handler

(method name)


class MyForm : Form{ Button button1 = new Button(); Label label1 = new Label ();

public MyForm() { ... this.Controls.Add(button1); this.Controls.Add(label1 ); } ...}

myForm

Form as container

• Form manages a list of controls– stored in Controls collection property

Controls button1 label1

all forms inheritControls collection

add to collection


What We Just Did?

• We have attached an event handler for the click event.

• Button has Click event• If this event happens (some one clicks on the

button)• button1_Click method will be executed.


SimpleForm8.csI like this code..

using System;using System.Threading;using System.Windows.Forms;

class SimpleForm{ public static void Main() { MyForm f1 = new MyForm(); Application.Run(f1); }}class MyForm : Form{ private TextBox textBox1; private Button button1;

public MyForm() { this.textBox1 = new System.Windows.Forms.TextBox(); this.button1 = new System.Windows.Forms.Button(); this.textBox1.Location = new System.Drawing.Point(72, 24); this.textBox1.Name = "textBox1"; this.button1.Location = new System.Drawing.Point(82, 59); this.button1.Name = "button1"; this.button1.Text = "button1"; this.button1.Click += new System.EventHandler(this.button1_Click); this.Controls.Add(this.button1); this.Controls.Add(this.textBox1); this.Name = "Form1"; this.Text = "Form1"; } private void button1_Click(object sender, EventArgs e) { int x = int.Parse(textBox1.Text); x = x * x; MessageBox.Show(x.ToString()); }}

Chapter 13. Graphical User Interface Concepts: Part 1

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Transcript of Chapter 13. Graphical User Interface Concepts: Part 1