Windows Application Concepts

Windows Forms Applications using C#.NET

•  It is a GUI (Graphical User Interface) application that runs on Windows o/s
•  A Windows Forms Application (Windows Application) is a collection of forms.                            
• Ex:  Notepad, WordPad, Paint, MS Word etc.

Form:

·         It is a graphics container, using which we can draw some graphics +  we can place some graphical controls such as labels, text boxes, buttons etc.

Steps for creating a form:

    1) Open vs 2010 or 2012

    2) File - New - Project

    3) Visual C# - Windows Forms Application.

    4) Project Name:  WinApp1

    5) Location = D:\

    6) Ok

Properties of Form:

   These are used change visual appearance of the form

1.      Text: used to change title of the form.

            Ex: Text = Welcome

2.      BackColor: used to specify background color of the form.

              Ex: BackColor = HotPink

3.      Size: used to specify width and height of the form.

              Ex: Size

                     Width = 500 (pixels)

                     Height = 200 (pixels)

4.      BackgroundImage:

it is used to applya background image for the form.

              Ex: BackgroundImage = sample.jpg

5.      BackgroundImageLayout:

it is used to specify tile / stretch of the background image.

            Ex: BackgroundImageLayout = Tile

6.      Cursor: it is used to specify mouse pointer while working in the form.

            Ex: Cursor = Hand

7.      Icon: it is used to specify icon file path.

            Ex: Icon = sample.ico

8.      ShowIcon: it is used to show / hide the icon of the form.

            Ex: ShowIcon = false

9.      ShowInTaskbar:  it is used to show / hide the form title in the windows taskbar.

            Ex:  ShowInTaskbar = false

10.  MinimizeBox:  it is used to show / hide the 'minimize box' of the form.

            Ex: MinimizeBox = false

11.  MaximizeBox:  it is used to show / hide the 'maximize box' of the form.

            Ex:  MaximizeBox = false

Note: if you specify 'MinimizeBox = false' and also 'MaximizeBox = false' at-a-time, both will be hidden.

12.  HelpButton:  it is used to show / hide the 'help button' (?) on the form.

            rule: MinimizeBox = false and MaximizeBox = false

13.  Opacity:  it is used to make the form transparent.

            Ex:  Opacity = 0% to 100%

14.  ControlBox:  it is used to show / hide the control box (minimize box + maximize box + close box) for the form.

            Ex:  ControlBox = false

15.  AutoScroll: it is used to show / hide the scroll bars on the form. this is useful when there some controls on the foirm.

            Ex: AutoScroll = true

16.  FormBorderStyle: it is used to specify whether the form is re-sizable at run time, or not.

            Options:  None / FixedSingle / Fixed3D / Sizable / FixedToolWindow / SizableToolWindow

17.  WindowState: it is used to identify / change current window status of the form, whether it is minimized / maximized.

            Options:  Normal / Minimized / Maximized

Event Driven Programming

·         In GUI applications, code execution flow is different from 'console apps'.

·         So GUI apps code execution is called as 'Event Driven Programming'.

·         Event: is an action that is performed by user at run time.

·         Ex:  When a door bell is pressed, sound is played.

                                   Here 'Press' is the event.

·         An event will its associated function, in which we can write any code.

Form events:

    These are the events (actions), done by the user, based on the form.

1.      Load:  it executes when the form runs (form loads into memory).

2.      Click:  it executes when the user clicks anywhere on the form.

3.      DoubleClick:  it executes when the user double clicks the form.

4.      Move:  it executes when the user moves the form at run time.

5.      Resize:  it executes when the resizes the form at run time.

6.      KeyPress:  it exeutes on pressing any key on the keyboard.

7.      Scroll:  it executes on scrolling the form at run time.

8.      FormClosing:  it executes on closing the form.

Ex:-

Develop a c# win app, to demonstrate the form events.

Steps:

·         Create a new c# win app.

            Project Name = FormEventsDemo

·         It shows 'Form1' automatically.

·         Go to properties window.

            (Right click on the form and say 'Properties')

·         Properties of Form1:

            Name = Form1

            BackColor = SkyBlue

·         Click on 'Events' icon in the properties window.

·         Double click on 'Load' event:

        private void MyForm_Load(object sender, EventArgs e)

        {

            MessageBox.Show("Welcome");

        }

·         Double click on 'Click' event:

        private void MyForm_Click(object sender, EventArgs e)

        {

            MessageBox.Show("You clicked the form at " + DateTime.Now.ToString());

        }

·         Double click on 'FormClosing' event:

        private void MyForm_FormClosing(object sender, FormClosingEventArgs e)

        {

            MessageBox.Show("Good bye");

        }

Changing form properties dynamically at run time:

  Ex: this.Text = "hello";

 These are used to change properties of the form, based on the user's requirement, through code.

·         Changing 'Text' property:

            Syntax:  this.Text = "some string here";

            Ex app:   Show good morning / good afternoon / Good evening message in the form's title bar, based on system time.

Note: When we double click on the form at design time, it generates code for 'Load' event.  Bcoz, 'Load' is the default event of the form.

·         Changing 'BackColor' property

            Syn:  this.BackColor = Color.yourcolorname;

            Ex App:  Develop a win app, which changes to darkgreen color when you double click it.

·         Changing 'BackgroundImage' property at run time:

            Syn:   this.BackgroundImage = Image.FromFile("file path here");

            Ex App:   show a background image, when the user press any key.

Working with WinForms Controls:-

·         A control is a GUI component, which can be displayed on a windows form.

·         Ex: Label, Button, TextBox etc.

·         C# recognizes each as a 'class'.

·         All the control classes are present under a namespace called 'System.Windows.Forms'.

                System.Windows.Forms

                       - Label

                       - Button

                       - TextBox

·         When you drag and drop a control from the Toolbox into the form, system automatically creates an object for the corresponding class.

Label

·         It is used to show a fixed message on the screen.

·         It is useful for showing:

            a) Titles

            b) Prompting text

            c) Description

 Properties of Label

·         Name: Used to specify programmatic name of the label.

o   Ex: Name = Label1

·         Text: Used to specify actual text of the label.

o   Ex: Text = Hello

·         BackColor: Used to specify background color of the label.

o   Ex: BackColor:  Green

·         ForeColor: Used to specify foreground color (text color) of the label.

o   Ex: ForeColor = Yellow

·         Font: Used to specify font settings of label such as font name, bold, italic, underline etc.

o   Ex: Arial, 30

·         Location: Used to specify position of the label on the foirm. It specifies X and Y co-ordinates.

o   Ex: Location

-          X = 300

-          Y = 200

·         AutoSize: Used to enable / disable automatic sizing for the label.

o   Ex: AutoSize = false

Events of Label

·         Click: Executes when you click on the label.

·         DoubleClick: Executes when you double click on the label.

·         MouseEnter: executes when you place mouse pointer over the label.

·         MouseLeave: executes when you move the mouse pointer outside the label.

Ex:-

Develop a c# win forms app, to show system date & time, when you click it.

Steps:

·         Create a new c# win form app.

o   Project Name = LabelDemo

·         Place 3 labels from tool box into the form.

·         Properties of Label1:

Ø  Font = Berlin Sans FB Demi, 30

Ø  Text = Welcome

Ø  ForeColor = DarkRed

·         Properties of Label2:

Ø  Font = Candara, 20

Ø  BackColor = DarkGreen

Ø  ForeColor = Yellow

·         Properties of Label3:

Ø  Font = Trebuchet MS, 14

Ø  AutoSize = false

Ø  Text = Click label2 to get system date and time

·         The form looks as shown below.

Code:

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Linq;

using System.Text;

using System.Windows.Forms;

namespace LabelDemo

{

    public partial class Form1 : Form

    {

        public Form1()

        {

            InitializeComponent();

        }

        private void label2_Click(object sender, EventArgs e)

        {

            label2.Text = DateTime.Now.ToString();

        }

    }

}

 Button:-

·         It is used to display a clickable command button on the for the user, and also execute some code when the user clicks it.

·         Ex: OK, Cancel etc.

Properties of Button:

·         Name, Text, BackColor, ForeColor, Font, Location, Size

·         Image: used to specify an icon image in button.

·         ImageAlign: specifies position of the image in the button.

·         TextAlign: specifies position on the text in the button.

Events of Button:

·         Click, MouseEnter, MouseLeave

Ex:-

Develop a c# win app, which contains Save & Exit buttons.

Steps:

·         Create a new c# win app.

o   Project Name = ButtonDemo

·         It shows Form1 automatically.

·         Place two buttons.

·         Properties of Button1:

§  Text = Save

§  Image = save.png

§  ImageAlign = MiddleLeft

§  TextAlign = MiddleRight

·         Properties of Button2:

§  Text = Exit

§  BackColor = DarkRed

§  ForeColor = Cyan

·         The form looks like this:

Code:-

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Linq;

using System.Text;

using System.Windows.Forms;

namespace ButtonDemo

{

    public partial class Form1 : Form

    {

        public Form1()

        {

            InitializeComponent();

        }

        //Code:

        private void button1_Click(object sender, EventArgs e)

        {

            MessageBox.Show("Saved!");

        }

        private void button2_MouseEnter(object sender, EventArgs e)

        {

            button2.BackColor = Color.Cyan;

            button2.ForeColor = Color.DarkRed;

        }

        private void button2_MouseLeave(object sender, EventArgs e)

        {

            button2.BackColor = Color.DarkRed;

            button2.ForeColor = Color.Cyan;

        }

        private void button2_Click(object sender, EventArgs e)

        {

            this.Close(); //closes the current working form

        }

    }

}

PictureBox:-

·         It is used to show an image on the form at desired place.

Properties of PictureBox:

·         Name, Image, Size, Location

·         SizeMode = Center / Stretch etc.

 Events of PictureBox:

·         Click, DoubleClick, MouseEnter, MouseLeave

Ex:-

Develop a win app, which shows an image, based on the selection.

  Steps:

·         Create a new c# win forms app.

o   Name = PictureBoxDemo

·         Drag & drop 7 buttons, 1 PictureBox on the form.

·         Properties of Button1:

o   Text = Small

·         Properties of Button2:

o   Text = Medium

·         Properties of Button3:

o   Text = Large

·         Properties of Button4:

o   Text = image 1

·         Properties of Button5:

o   Text = image 2

·         Properties of Button6:

o   Text = image 3

·         Properties of Button7:

o   Text = image 4

·         Properties of PictureBox1:

o   SizeMode = Zoom

o   Image = img1.jpg

·         Properties of Form1:

o   Text = Image Viewer

o   WindowState = Maximized

·         The form looks like this:

Code:-

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Linq;

using System.Text;

using System.Windows.Forms;

namespace PictureBoxDemo

{

    public partial class Form1 : Form

    {

        public Form1()

        {

            InitializeComponent();

        }

        //Code:

        private void button1_Click(object sender, EventArgs e)

        {

            pictureBox1.Size = new Size(100, 100);

        }

        private void button2_Click(object sender, EventArgs e)

        {

            pictureBox1.Size = new Size(200, 200);

        }

        private void button3_Click(object sender, EventArgs e)

        {

            pictureBox1.Size = new Size(300, 300);

        }

        private void button4_Click(object sender, EventArgs e)

        {

            pictureBox1.Image = Image.FromFile(@"E:\Harsha\Images\WallPapers\img1.jpg");

        }

        private void button5_Click(object sender, EventArgs e)

        {

            pictureBox1.Image = Image.FromFile(@"E:\Harsha\Images\WallPapers\img2.jpg");

        }

        private void button6_Click(object sender, EventArgs e)

        {

            pictureBox1.Image = Image.FromFile(@"E:\Harsha\Images\WallPapers\img3.jpg");

        }

        private void button7_Click(object sender, EventArgs e)

        {

            pictureBox1.Image = Image.FromFile(@"E:\Harsha\Images\WallPapers\img4.jpg");

        }

    }

}

TextBox:-

·         It is used to accept a string value from keyboard.

·         Types of text boxes:

            a) Single line text box (default)

            b) Multi line Text box

            c) Password text box

Properties of TextBox:

·         Name, Text, BackColor, ForeColor, Size, Location, Cursor

·         MaxLength: Used to specify maximum no. of chars that can be typed in the text box.

o   Ex: MaxLength = 30

·         PasswordChar: used to specify char of password.

o   Ex: PasswordChar = *

·         Multiline: true / false

o   It is used to make the text as multi line text box.

o   Ex:  MultiLine = true

·         ScrollBars = None / Horizontal / Vertical / Both

o   It is used to show scroll bars with in the multi line text box.

·         ReadOnly = true / false

o   It is used to make the text box, read-only.

o   Ex:  ReadOnly = true

·         Enabled = true / false

o   It is used to enable / disable the text box. when you disable the text box, its events will not be executed.

o   Ex: Enabled = false

·         Visible = true / false

o   It is used to show / hide the text box.

o   Ex: Visible = false

·         TabIndex:  It is used to specify tab order of the text boxes. you must provide an incremental for the tab index.

Events of TextBox:

·         Click, DoubleClick, MouseEnter, MouseLeave

·         TextChanged:  it executes on changing text value at run time. that means it executes on typing / erasing the text at run time.

·         KeyPress: it executes on pressing any key on the board, while working in the text box. using we can also block required chars not be typed in the text box.

Ex:-

Develop a simple c# win form app, which shows 'hi' message to user.

 Steps:

·         Create a new c# win app.

o   Project Name = TextBoxDemo1

·         Design the form as shown below.

Code:-

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Linq;

using System.Text;

using System.Windows.Forms;

namespace TextBoxDemo1

{

    public partial class Form1 : Form

    {

        public Form1()

        {

            InitializeComponent();

        }

        //Code

        private void button1_Click(object sender, EventArgs e)

        {

            MessageBox.Show("Hi, " + textBox1.Text + " " + textBox2.Text);

        }

        private void button2_Click(object sender, EventArgs e)

        {

            this.Close();

        }

    }

}

Ex:-

Develop a registration form using c# win forms.

  Steps:

·         Design a form as shown below.

·         Properties of TextBox1:

-          Name = txtStudentName

-          MaxLength = 30

·         Properties of TextBox2:

-          Name = txtAge

-          MaxLength = 2

·         Properties of TextBox3:

-          Name = txtPassword

-          MaxLength = 30

-          PasswordChar = *

·         Properties of TextBox4:

-          Name = txtRetypePassword

-          MaxLength = 30

-          PasswordChar = *

·         Properties of TextBox5:

-          Name = txtAddress

-          Multiline = true

-          Scrollbars = Vertical

·         Properties of TextBox6:

-          Name = txtQualification

·         Properties of TextBox7:

-          Name = txtCourseName

-          Text = .NET

-          ReadOnly = true

·         Properties of TextBox8:

-          Text = PEERS

-          Enabled = false

·         Design the form as shown below.

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Linq;

using System.Text;

using System.Windows.Forms;

namespace TextBoxDemo2

{

    public partial class Form1 : Form

    {

        public Form1()

        {

            InitializeComponent();

        }

        private void button1_Click(object sender, EventArgs e)

        {

            //declare the variables

            string StudentName;

            int Age;

            string Password, RetypePassword, Address, Qualification, CourseName, InstituteName;

            //read values from controls

            StudentName = txtStudentName.Text;

            Age = Convert.ToInt32(txtAge.Text);

            Password = txtPassword.Text;

            RetypePassword = txtRetypePassword.Text;

            Address = txtAddress.Text;

            Qualification = txtQualification.Text;

            CourseName = txtCourseName.Text;

            InstituteName = txtInstituteName.Text;

            //show message

            string msg = "";

            msg += "Your registration accepted!";

            msg += "\nStudent Name: " + StudentName;

            msg += "\nAge: " + Age;

            msg += "\nPassword: " + Password;

            msg += "\nRe-type Password: " + RetypePassword;

            msg += "\nAddress: " + Address;

            msg += "\nQualification: " + Qualification;

            msg += "\nCourse Name: " + CourseName;

            msg += "\nInstitute Name: " + InstituteName;

            MessageBox.Show(msg);

        }

    }

}

Working with "Auto Complete" feature in Text Box:

·         It shows the list of matching items, while typing the text in the TextBox.

·         It is of two types:

            a) Auto-List from hard disk file system

            b) Auto-List from a user defined collection

a) Auto-List from hard disk File system:

·         It shows list of file names & folder names automatically.

·         Properties of TextBox:

Ø  AutoCompleteMode = Suggest

Ø  AutoCompleteSource = FileSystem

b) Auto-List from a user defined collection:

·         It shows list of items when you type atleast 1 char in the text box.

·         Properties of TextBox:

Ø  AutoCompleteMode = Suggest

Ø  AutoCompleteSource = CustomSource

Ø  AutoCompleteCustomSource = item 1

                                                                item 2

                                                                 .....

Ex:-

Demo on 'AutoComplete':

·         Create a new c# win app, and place 3 labels and 3 text boxes.

·         Properties of TextBox1:

-          AutoCompleteMode = Suggest

-          AutoCompleteSource = FileSystem

·         Properties of TextBox2:

-          AutoCompleteMode = Suggest

-          AutoCompleteSource = FileSystemDirectories

·         Properties of TextBox3:

-          AutoCompleteMode = Suggest

-          AutoCompleteSource = CustomSource

-          AutoCompleteCustomSource = Uttar Pradesh

               Maharashtra

               .....

Working with 'TextChanged' event of TextBox:

·         This event executes, when the user types / erases any text in the textbox, at run time.

Ex:-

Develop a c# win app, to show net price automatically, based on the actual product price, discount = 10% on product price

Steps:

·         Create a new c# win app.

·         Project Name = TextChangedEventDemo

·         Design form1 as shown below.

Code:

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Linq;

using System.Text;

using System.Windows.Forms;

namespace TextChangedEventDemo

{

    public partial class Form1 : Form

    {

        public Form1()

        {

            InitializeComponent();

        }

        //code:

        private void textBox1_TextChanged(object sender, EventArgs e)

        {

            //get current value of textbox1

            string str = textBox1.Text;

            if (str == "")

            {

                label4.Text = "Unknown";

                label5.Text = "Unknown";

            }

            else

            {

                double Price = Convert.ToDouble(textBox1.Text);

                double Discount = Price * 10 / 100;

                double NetPrice = Price - Discount;

                //show output in labels

                label4.Text = Convert.ToString(Discount);

                label5.Text = Convert.ToString(NetPrice);

            }

        }

    }

}

Working with 'KeyPress' event of text box:

·         This event executes when the user press any key on the keyboard, while workinbg in the text box.

·         This event may also be used to prevent typing un-expected chars in a textbox.

Steps:

·         Create a new c# win app, which accepts alphabets only in TextBox1 & 2;   numbers only in TextBox3.

Code:

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Linq;

using System.Text;

using System.Windows.Forms;

namespace KeyPressEventDemo

{

    public partial class Form1 : Form

    {

        public Form1()

        {

            InitializeComponent();

        }

        //Code

        private bool CheckAlphabet(char ch)

        {

            char[] AllowedChars = new char[] { 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', ' ', '\b' };

            if (Array.IndexOf(AllowedChars, ch) >= 0)

                return (false); //accept it

            else

                return (true); //reject it

        }

        private bool CheckNumber(char ch)

        {

            if (ch == '1' || ch == '2' || ch == '3' || ch == '4' || ch == '5' || ch == '6' || ch == '7' || ch == '8' || ch == '9' || ch == '0')

                return false; //accept it

            else

                return true; //reject it

        }

        private void txtFirstName_KeyPress(object sender, KeyPressEventArgs e)

        {

            e.Handled = this.CheckAlphabet(e.KeyChar);

        }

        private void txtLastName_KeyPress(object sender, KeyPressEventArgs e)

        {

            e.Handled = this.CheckAlphabet(e.KeyChar);

        }

        private void txtAge_KeyPress(object sender, KeyPressEventArgs e)

        {

            e.Handled = this.CheckNumber(e.KeyChar);

        }

    }

}

Container Controls:-

·         These are used to contain various other controls inside.

·         C# supports two types of containers

            1) Form (Outer container)

            2) Sub container

·         Sub containers are used to divide the form as no. of units.

·         Sub Containers (Container Controls) in c#:

            1) Panel

            2) GroupBox

            3) TabControl

            4) FlowLayoutPanel

Panel:-

·         It is a sub container, in which you can place any controls.

·         It allows its inner controls to be located based X and Y co ordinates.

Properties of Panel:

·         BackColor, ForeColor, Font, BackgroundImage, Size, Location, Cursor etc.

Events of Panel:

·         MouseMove, MouseEnter, MouseLeave etc.

Ex:-

Demo on mouse move?

Code:

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Linq;

using System.Text;

using System.Windows.Forms;

namespace PanelDemo1

{

    public partial class Form1 : Form

    {

        public Form1()

        {

            InitializeComponent();

        }

        //code

        private void panel1_MouseMove(object sender, MouseEventArgs e)

        {

            label1.Text = e.X + ", " + e.Y;

        }

        //note: 'EventArgs e' is a small variable, that is available in every event handler, which provides additional info about current action.

    }

}

GroupBox:

·         It is same as Panel, but can show a title also.

·         Properties of GroupBox:

·         Text, BackColor, ForeColor, Font, BackgroundImage, Size, Location, Cursor etc.

·         Events of GroupBox:

·         MouseMove, MouseEnter, MouseLeave etc.

TabControl:

·         It is used to show any one tab to the user.

·         TabControl is a collection of 'tab pages'.

Steps for development of TabControl:

·         Drag & drop TabControl into the form.

·         Note: by default, it creates two tab pages.

·         Select 'TabControl1' and goto 'TabPages' property

In this property, we can add / remove the pages.

·         Place controls directly in the tab pages.

Ex:-

Develop a c# win app, which shows 'user profile'.

·         Design the form as shown below:

FlowLayoutPanel:

·         It is used to 'automatically arrange' the controls in an relative order.

Ex:-

Develop a 'PhotoGallery' app, using 'FlowLayoutPanel'.

Steps:

·         Create a new c# win app.

·         Drag & drop 'FlowLayoutPanel' from Toolbox into the form.

·         Drag & drop 9 picture boxes into 'flowlayoutpanel'.

·         Set 'Image' property of all picture boxes.

·         Set 'SizeMode = Stretch' for all picture boxes.

·         Properties of 'FlowLayoutPanel1':

            BackColor = { any color }

            AutoScroll = true

Dynamic Creation of Controls:- (or)

Creating Controls at run time:-

·         It is used to generate controls dyanamically at run time.

·         Controls can be created in two ways:

            a) Static Control Creation

            b) Dynamic Control Creation

a) Static Control Creation

·         Drag & drop the controls from Toolbox.

·         Easy to create

·         This is good if the developer knows, how many controls he wants.

b) Dynamic Control Creation

·         Create control objects thru code (programmatically).

·         A bit difficult

·         This is good if the developer dont know, how many controls he wants.

Steps for dynamic controls creation:

·         Create an object for the control class.

Ø  Label L1 = new Label();

·         Add necessary properties to the object:

Ø  L1.Text = "some text";

Ø  L1.Font = new Font("font name", size);

Ø  L1.Location = new Point(x, y);

Ø  L1.Size = new Size(width, height);

Ø  L1.BackColor = Color.colorname;

Ø  L1.ForeColor = Color.colorname;

Ø  etc.

·         Handle the events:

Ø  L1.Click = new System.EventHandler(L1_Click);

·         Add controls to the container:

Ø  this.Controls.Add(L1);

                                (or)

Ø  flowLayoutPanel1.Controls.Add(L1);

Ex:-

Develop an app, which produces 'n' text boxes at run time.

Steps:

·         Create a new c# win app.

Ø  Project Name: DynamicControlsCreationDemo

·         Drag & drop 1 label, 4 buttons, 1 flowlayoutpanel, 1 more button.

·         Properties of label1:

Ø  Text = How many friends you have

·         Properties of button1:

Ø  Text = 5

·         Properties of button2:

Ø  Text = 10

·         Properties of button3:

Ø  Text = 20

·         Properties of button4:

Ø  Text = 30

·         Properties of FlowLayoutPanel1:

Ø  BackColor = {any color}

Ø  AutoScroll = true

·         Properties of button5:

Ø  Text = OK

Code:

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Linq;

using System.Text;

using System.Windows.Forms;

namespace DynamicControlsCreationDemo

{

    public partial class Form1 : Form

    {

        public Form1()

        {

            InitializeComponent();

        }

        //Code:

        //user-defined method

        private void GenerateTextBoxes(int n)

        {

            flowLayoutPanel1.Controls.Clear();

            for (int i = 1; i <= n; i++)

            {

                //step 1: create an object the control class

                TextBox txt = new TextBox();

                //step 2: set necessary prop

                txt.Name = "TextBox" + i;

                txt.BackColor = Color.Aqua;

                //step 3: add text box to the container

                flowLayoutPanel1.Controls.Add(txt);

            }

        }

        private void button1_Click(object sender, EventArgs e)

        {

            this.GenerateTextBoxes(5);

        }

        private void button2_Click(object sender, EventArgs e)

        {

            this.GenerateTextBoxes(10);

        }

        private void button3_Click(object sender, EventArgs e)

        {

            this.GenerateTextBoxes(20);

        }

        private void button4_Click(object sender, EventArgs e)

        {

            this.GenerateTextBoxes(30);

        }

        private void button5_Click(object sender, EventArgs e)

        {

            for (int i = 0; i < flowLayoutPanel1.Controls.Count; i++)

            {

                TextBox txt = (TextBox)flowLayoutPanel1.Controls[i];

                string s = txt.Text;

                MessageBox.Show(s);

            }

        }

    }

}

Working with 'Menus' in win forms:

·         Menu:  it is a collection of options.

·         Two types of menus:

Ø  MenuStrip

Ø  ContextMenuStrip

MenuStrip:-

·         Used to create menu bars.

·         Ex:   File   Edit   View

ContextMenuStrip:

·         Used to create 'right click menus'.

Steps for working with 'MenuStrip':

·         Drag & drop 'MenuStrip' control from Toolbox into the form.

Ø  Toolbox > Menus & Toolbars > MenuStrip

·         Design menu items in menu strip, by clicking on 'Type here' message.

·         Handle 'Click' events for all menu items (menu options).

·         Run the app, and click on the menu item.

Ex:-

Develop a c# win app, with following menu.

BackgroundColor	BackgroundImage	Window	Exit
Light Yellow	Sunset	Normal
Pink	Water lilies	Minimize
Chocolate	None	Maximize
Blue

               

                             

Code:                                 

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Linq;

using System.Text;

using System.Windows.Forms;

namespace MenuStripDemo2

{

    public partial class Form1 : Form

    {

        public Form1()

        {

            InitializeComponent();

        }

        //Code

        private void lightYellowToolStripMenuItem_Click(object sender, EventArgs e)

        {

            this.BackColor = Color.LightYellow;

        }

        private void pinkToolStripMenuItem_Click(object sender, EventArgs e)

        {

            this.BackColor = Color.Pink;

        }

        private void chocolateToolStripMenuItem_Click(object sender, EventArgs e)

        {

            this.BackColor = Color.Chocolate;

        }

        private void blueToolStripMenuItem_Click(object sender, EventArgs e)

        {

            this.BackColor = Color.Blue;

        }

        private void sunsetToolStripMenuItem_Click(object sender, EventArgs e)

        {

            this.BackgroundImage = Image.FromFile(@"C:\Documents and Settings\All Users\Documents\My Pictures\Sample Pictures\Sunset.jpg");

            sunsetToolStripMenuItem.Checked = true;

            waterLiliesToolStripMenuItem.Checked = false;

            noneToolStripMenuItem.Checked = false;

        }

        private void waterLiliesToolStripMenuItem_Click(object sender, EventArgs e)

        {

            this.BackgroundImage = Image.FromFile(@"C:\Documents and Settings\All Users\Documents\My Pictures\Sample Pictures\Water lilies.jpg");

            waterLiliesToolStripMenuItem.Checked = true;

            sunsetToolStripMenuItem.Checked = false;

            noneToolStripMenuItem.Checked = false;

        }

        private void noneToolStripMenuItem_Click(object sender, EventArgs e)

        {

            this.BackgroundImage = null;

            noneToolStripMenuItem.Checked = true;

            sunsetToolStripMenuItem.Checked = false;

            waterLiliesToolStripMenuItem.Checked = false;

        }

        private void normalToolStripMenuItem_Click(object sender, EventArgs e)

        {

            this.WindowState = FormWindowState.Normal;

        }

        private void minimizeToolStripMenuItem_Click(object sender, EventArgs e)

        {

            this.WindowState = FormWindowState.Minimized;

        }

        private void maximizeToolStripMenuItem_Click(object sender, EventArgs e)

        {

            this.WindowState = FormWindowState.Maximized;

        }

        private void exitToolStripMenuItem_Click(object sender, EventArgs e)

        {

            this.Close();

        }

        private void Form1_FormClosing(object sender, FormClosingEventArgs e)

        {

            if (MessageBox.Show(

                "Are you sure to close?",

                "Peers",

                MessageBoxButtons.YesNo) == System.Windows.Forms.DialogResult.Yes)

            {

                //code for yes

                //system will automatically closes the form

            }

            else

            {

                //code for no

                e.Cancel = true; //stops closing the form

            }

        }

    }

}

ContextMenuStrip:

·         It is used to create 'right click menus'

Steps for working with 'Context menu Strip':

·         Drag & drop 'ContextMenuStrip' control from toolbox.

·         Create menu items in 'ContextMenuStrip'

·         Set the property of required control (or) form

Ø  ContextMenuStrip = { name of your context menu strip }

·         Handle click events of each menu item.

·         Run the app, right on the required control (or) form & click on the menu item.

ToolStrip:

·         It is used to create tool bars.

·         A tool bar is a collection of 'tool bar buttons'.

Steps for working with 'ToolStrip':

·         Drag & drop 'ToolStrip' control from toolbox.

Ø  Toolbox > Menus&Toolbars > ToolStrip

·         Go to 'Items' property of 'ToolStrip' and add required buttons.

·         Double click on each toolbar button and handle the 'Click' event.

ImageList:

·         It is a collection of few images.

·         It is used to apply images to 'menu items' (or) tool bar buttons.

Ex:-

Demo on contextmenu, imagelist, toolstrip

·         Properties of TextBox1:

Ø  ContextMenuStrip = ContextMenuStrip1

Code:

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Linq;

using System.Text;

using System.Windows.Forms;

namespace ContextMenuStripDemo

{

    public partial class Form1 : Form

    {

        public Form1()

        {

            InitializeComponent();

            //any code

        }

        //code:

        private void cutToolStripMenuItem_Click(object sender, EventArgs e)

        {

            textBox1.Cut();

        }

        private void copyToolStripMenuItem_Click(object sender, EventArgs e)

        {

            textBox1.Copy();

        }

        private void pasteToolStripMenuItem_Click(object sender, EventArgs e)

        {

            textBox1.Paste();

        }

        private void Form1_Load(object sender, EventArgs e)

        {

            //applies source of the images to context menu strip

            contextMenuStrip1.ImageList = imageList1;

            //apply image index to the menu items

            cutToolStripMenuItem.ImageIndex = 0;

            copyToolStripMenuItem.ImageIndex = 1;

            pasteToolStripMenuItem.ImageIndex = 2;

            //apply source of the images to toolstrip1

            toolStrip1.ImageList = imageList1;

            //apply image index to the tool bar buttons

            toolStripButton1.ImageIndex = 0;

            toolStripButton2.ImageIndex = 1;

            toolStripButton3.ImageIndex = 2;

        }

        private void toolStripButton1_Click(object sender, EventArgs e)

        {

            textBox1.Cut();

        }

        private void toolStripButton2_Click(object sender, EventArgs e)

        {

            textBox1.Copy();

        }

        private void toolStripButton3_Click(object sender, EventArgs e)

        {

            textBox1.Paste();

        }

    }

}

Programming Model of a form:

·         C# recognizes each form as a class.

·         Generally a class contains 3 types of members:

·         Data members:

Ø  All the controls that are placed within the form.

·         Properties:

Ø  Text, Backcolor, WindowState etc.

·         Methods:

Ø  Event handlers

Ø  User-defined methods

Rules a form class:

·         A form class must be a partial class.

            public  partial  class Form1 : Form

            {

            }

·         Observation:  for every form, visual studio generates 2 files automatically.

            Ex:  Form1.cs

                   Form1.Designer.cs

·         Form1.cs:  contains user-defined code of the form, like event handlers & user-defined methods.

·         Form1.Designer.cs:  contains system-generated code (designer code)

·         Every form must be a child class of 'System.Windows.Forms.Form' class

Ø  It provides designer winow + form properties + form events to the child class.

·         Every form should contain a constructor, with InitializeComponent() method.

Ø  It internally calls the system defined code.

Code execution sequence of the form:

·         System allocates some memory for the form object.

·         Constructor

·         Form1_Load()

·         Other event handlers, based on the action done by user,

Ø  ex: button1_Click

·         Form1_FormClosing

Working with 'Popup windows' in Win forms:

·         These are used to open another form when you click on a button in the first form.

Steps:

·         Add form to the project:

Ø  Solution Explorer > Right click on the project name > Add -> New Item -> Windows Form -> Name = Form2.cs -> Add.

·         Create an object for 'Form2' class:

Ø  Form2  f = new Form2();

·         Show it:

Ø  f.ShowDialog();

·         Pass any data to the form (optional):

Ø  f.Tag = value;

Ex:-

Develop a c# win form app, which shows 'hello' message to the user, in popup window.

Steps:

·         Create a new c# win app

Ø  Project Name = PopupWindowDemo

·         Add 'Form2' to the project.

·         Design form1 as shown below

       

·         Design form2 as shown below

Code for form1:

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Linq;

using System.Text;

using System.Windows.Forms;

namespace PopupWindowsDemo

{

    public partial class Form1 : Form

    {

        public Form1()

        {

            InitializeComponent();

        }

        //Code in 'Form1':

        private void button1_Click(object sender, EventArgs e)

        {

            //create an object for Form2

            Form2 f2 = new Form2();

            //add data to f2

            //f2.Tag = textBox1.Text;

            Class1 c1 = new Class1();

            c1.a = 10;

            c1.b = 20;

            f2.Tag = c1;

            //show f2

            f2.ShowDialog();

        }

    }

}

Code for form2:

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Linq;

using System.Text;

using System.Windows.Forms;

namespace PopupWindowsDemo

{

    public partial class Form2 : Form

    {

        public Form2()

        {

            InitializeComponent();

        }

        //code in 'Form2':

        private void Form2_Load(object sender, EventArgs e)

        {

            //label1.Text = "Welcome, " + Convert.ToString(this.Tag);

            //this.Text = "Welcome, " + Convert.ToString(this.Tag);

            Class1 c1 = (Class1)this.Tag;

            MessageBox.Show(c1.a.ToString());

            MessageBox.Show(c1.b.ToString());

        }

    }

}

'ErrorProvider' control in WinForms:

·         It is used to validate the input fields, whether they are correctly entered or not.

Ex:-

Demo on ‘Errorprovider’ control

·         Design form1 as shown below

Code:

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Linq;

using System.Text;

using System.Windows.Forms;

namespace ErrorProviderDemo

{

    public partial class Form1 : Form

    {

        public Form1()

        {

            InitializeComponent();

        }

        //double click on 'Leave' event of TextBox1

        private void textBox1_Leave(object sender, EventArgs e)

        {

            //get email from text box

            string Email = textBox1.Text;

            //check

            if (Email.IndexOf(" ") == -1 &&

                (Email.EndsWith(".com") || Email.EndsWith(".co.in")) &&

                Email.IndexOf("@") > 0)

                errorProvider1.SetError(textBox1, ""); //no error msg

            else

                errorProvider1.SetError(textBox1, "Invalid e-mail"); //show message

        }

    }

}