programming environment and writing programs

8/7/2019 Programming Environment and Writing Programs

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Programming Environment and WritingPrograms

Starting a New VB Project

1. To start a new Visual Studio window click on Start All

Programs Microsoft Visual Studio 2003 .NET

Microsoft Visual Studio 2003 .NET.

2. Following window will appear on the screen.

3. In the Start Page window, click the New Project button or

click File New Project… or click Ctrl +N.

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4. In the Project types click on Visual Basic Projects.

5. In the Templates side choose Windows Application (or other

whichever required).

6. Type the name of the new project.

7. Chose project location in Location. Click on browse to

navigate to your folder.

8. Now click Open.

9. New Project dialog box appear again.

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10.Click OK button.

11.The Form1 appears on the screen.

12. This is the Design mode of the program.

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13.To view the code window, double click on Form1 or click on

the Solution Explorer and click on the View Code icon in

the Solution Explorer.

14.To close the project click on File Close Project

NOTE:

• When you are editing code in the code window always

remember to stop the application first.

• A project or program is run by pressing the F5

button or pressing Start button and is stopped

by pressing Stop Debugging button .

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Code




Chang ing Form Properties from the properties Window

1. Click on Form1 and then click the

Properties window located at the right

side of the Form1.2. If it is not visible then press F4 or

click on View menu and select Properties

Window.

3. The Text field that contains the name for

Form1 appears highlighted in the

Properties window.

4. If the Text field does not appear, scroll

through the Properties window until you

reach the Text attribute under the

Attributes heading.

5. Double-click the Text

6. Write MyFirstForm in place of Form1.

7. Press Enter.

8. The Text appearing at the title bar of

the form.

9. In the similar way we can change other

form properties.

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Adding Some Common Controls to the Form

1. Switch to the Design View of the form and click on Toolbox

on left the main window.

2. If Toolbox is not visible then in the

menu bar click on View Toolbox or

press Ctrl+Alt+X to show it.

3. Click on the Windows Forms tab in the

Toolbox.

4. A list of common controls will appear

in the list.

5. Add two TextBox and a Button on the

form.

6. We can do this by dragging and dropping

on the main form or double clicking onthe control.

7. Now arrange the control on the form and

arrange them as shown.

8. Set the text property of the button to

Add and Name as cmdAdd.

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9. Set to text property of the two textboxes as nothing/no

text.

10.Set the name property of the two TextBox as txtNum1 and

txtNum2.

11.Your from should look like this now.

12.Double click on the Add button.

13.This will take us to the Code window of the click event of

the Add button.

Dim a, b As Doublea = Val(txtNum1.Text)b = Val(txtNum2.Text)MsgBox("Sum of numbers is " & a + b, , "Addition")

14.First we have declared two variables a and b of data type

Double.

15.In the second and third lines we have assigned them the

values which will be typed in the textboxes.

16.Line four shows a message box which will show the result of

the sum of the two numbers a and b.

17.Now press F5 to run the program.

18.Type the numbers as 45 and 35 and press Add button.

19.A message box will show a message that “The sum of numbers

is 80”.

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Implicit Conversion

1. Start Visual Studio.

2. Create a new Windows Application VB Project.

3. Provide a name of the project as Casting.4. Place two controls on the Form1, first a Label control and

second a Command Button.

5. Name the button as btnIC.

6. Give the text property as “Implicit Conversion”.

7. Your form should look like this as shown below.

8. Double click the command button and type the following code

in the procedure body.

Dim shortVal As Short = 5Dim SingleVal As Single = 10.5Dim doubleResult As Double

doubleResult = SingleVal * shortValLabel1.Text = "Implicit Conversion->Double:" & SingleVal _

& "*" & shortVal & " = " & doubleResult

9. In the first line we have declared and initialized an

integer type variable as shortVal.

10.In the second line we have declared and initialized a

floating point variable singleVal, and in the third line

doubleResult is declared as double.

11.Next we multiply the first two variables and assign the

result to doubleResult variable in the fourth line.

12.The result is stored as double, because doubleResult is a

double variable.

13. The next line prints the result in the Label1.

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14.To exactly find the data type of the doubleResult, add this

line of the code at the end.

MsgBox(doubleResult.GetType.ToString)

15. Run this application, and press the command button, we get

this result.

16. The message box shows the type of the data whichdoubleResult has.

Explicit Conversion

1. Add a new command button on the form.

2. Name it as btnEC.

3. Give it the text property as “Explicit Conversion”.

4. Now Form1 should look like this.

5. Double click the button and type the following code in the

procedure body.

Dim shortResult As ShortDim SingleVal As Single = 10.5shortResult = CShort(SingleVal)Label1.Text = "Explicit, -> short: " & SingleVal & " -> " &

shortResultMsgBox(shortResult.GetType.ToString)

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6. Now we have changed a floating point variable into an

integer type variable.

7. The next line shows its type in a message box.

Explicit Conversions Using the Convert Commands

1. Place a new control of command button on the same form.

2. Give the text property of the button as “Explicit

Conversions Using the Convert Commands”

3. Give the name property as btnExCnv .

4. Form1 should look like this now.

5. Double click on the button and type the following code in

the procedure body.

Dim doubleVal As Double = 99.999Dim stringResult As StringDim boolVal As Boolean = True

stringResult = Convert.ToString(boolVal) &Convert.ToString(doubleval)Label1.Text = "Explicit, -> string: " & boolVal & " and "

doubleval & " -> " & stringResultMsgBox(stringResult.GetType.ToString)

6. We have doubleval as 99.999, boolVal as True.

7. stringResult is a string variable which has been assigned

the converted values of doubleVal and boolVal as string and

both have been joined.

8. The rest of the code does the same work as we have

mentioned before.

9. Run the application

10.Press the btnExCnv button.

11. We will get the result as shown in figures below.

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Mixed Conversions Using the Convert Commands

1. Similarly place a new command button control on the form.

2. Give the text property of the button as “ Mixed Conversions

Using the Convert Commands”

3. Give the name property as btnMxdCnv .

4. Form1 should look like this now.

5. Double click the new button and type the following code in

its procedure body.

Dim integerVal As Integer = 67Dim longResult As LongDim stringVal As String = "17"longResult = integerVal + Convert.ToInt64(stringVal)Label1.Text = "Mixed, -> long: " & integerVal &

stringVal & " -> " & longResultMsgBox(longResult.GetType.ToString)

6. Here we have converted the stringVal variable into Long using the convert

method and added the result to the integerVal and saved into the

longResult variable of type Long.

7. To test the result run the application and press the button.

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Calculating the Area of a Rectangle

1. Create a new Windows Application and name it as RectA .

2. Place one command button, two textboxes and four labels on

Form1.3. Set the Form1 Text as “ Area of a Rectangle” from Properties

Window.

4. Similarly set lable1 Text as Length and label2 Text as

Breadth., and label3 text as “Enter Data”

5. Set label4 Text as “Click Button to Calculate Area”, and

from Font set Bold as True.

6. Set Text of textbox1 and textbox2 as empty.

7. Set the Name of button as “cmdAreaR ”, and Text as

“Calculate”.

8. Arrange your controls on the form as such they look like

this:

9. Double click the Calculate button.

10.Type the following code in the cmdRectArea method body.

If TextBox1.Text = "" Or TextBox2.Text = "" ThenMsgBox("Please enter complete data!",

MsgBoxStyle.Information, "Incomplete Data")Else

Label4.Text = "Area of the rectangle is " &CDbl(TextBox1.Text) * CDbl(TextBox2.Text)End If

11.The if condition checks that both values of length and

breadth ager supplied by the user.

12. Else contains the calculation of the area with a string

joined with it.

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13.Press F5 to Start the application.

14.Enter the values for Length and Breadth as 25 and 1000.

15. Click the Calculate button.

16. We will get the following result as shown below:

17. Close the application.

Convert Temperature in oF to oC

1. Create a new Windows Application and name it as F2C.

2. Design the Form1 as depicted below.

3. If the temperature in degree Fahrenheit is OF and

temperature in degree centigrade is OC, then their

conversion formulae are given as:

OC = (OF – 32) * 5/9

O

F = 9/5 *

O

C +32

4. Go to the code window, and from the controls list select

Textbox1.

5. In the events list of the Textbox1 select TextChanged event.

6. Type the following code in the procedure body.

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Try Dim a As Double

a = Math.Round((Convert.ToDouble(TextBox1.Text) -32 ) * 5 / 9, 2)

Label2.Text = "Temperature in degree Centigrade = " +

a.ToString()Catch ex As ExceptionTextBox1.Text = 0

End Try

1. Press F5 and enter temperature in the textbox as 220.

2. We shall get the temperature converted into degree

Fahrenheit as shown below.

Convert Temperature in oC to oF

1. Now create a new project and convert temperature from

degree centigrade to degree Fahrenheit yourself.

Finding the Square of a Number using ListBox

1. Create a new Windows Application as SquareNum .

2. Create the interface of the application as depicted below:

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3. Double click the command button “Find Square”.


Trysquare()

Catch ex As ExceptionTextBox1.Text = 0End Try

5. Where square() is a procedure which finds the square of a

number. Its coding is:

Public Sub square() Dim sqr As Double

sqr = Math.Pow(CDbl(TextBox1.Text), 2)ListBox1.Items.Add("Square of " & TextBox1.Text &" is " & sqr)

End Sub

6. Now press F5.

7. Type some number in the textbox and press the command

button.

8. We shall get the squares of the numbers as desired.

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Checking Number

1. Create a new Windows Application as NumCheck.


3. Set the text property of the button as “Click Me!”.

4. Set the name property of the textbox as txtNo and text

property as 0.

5. Double click the command button and enter the following

code in the procedure body.

If (CInt(txtNo.Text) > 0 And CInt(txtNo.Text) < 11) ThenMsgBox("You have clicked " & txtNo.Text,

MsgBoxStyle.OKOnly, "Number")Else

MsgBox("You did not enter number from 1 to 10")End If

6. We have used an if statement to check numbers from 1 to 10or entered or not.

7. Run this application.

8. Type some number and click the button.

9. Do not enter any other character other than numbers from

0-9 otherwise error will occur.

10. Errors may be controlled by using different other coding

techniques.

A Simple Calculator

1. Create a new Windows Application as Calculator.


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3. Set the properties of different controls as appropriate.

4. We have set name properties of radio buttons as rbAdd ,

rbSubt, rbMul,and rbDiv for Add , Subtract, Multiply, and

Divide respectively.5. Set the name property of the label at the bottom as lblRes,

and name as Result:

6. Go to the code window and from the controls’ list, select

rbAdd and select click event from the events.


TrylblRes.Text = ""lblRes.Text = "Sum = " & CDbl(txtOp1.Text) + Dbl(txtOp2.Text)

Catch ex As ExceptionMsgBox("Enter correct data!")

End Try

8. Run the application.

9. Type the operand’s values in the textboxes as 10 and 20.

10. Click on Add radio button, we will get the result printed

at the bottom as shown in figure.

11. You may code for other click events of the radio buttons

which is left as an exercise for the participants.

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Creating a list of Numbers---Use of For with IF…Else

1. Create a new Windows Application as SquareNum .2. Create the interface of the application as depicted below:

3. Set the name property of the first textbox box as

txtStart, and text property as 0.

4. Set the name property of the second textbox box as txtEnd,

and text property as 0.

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5. Set the text property of the labels as shown above.

6. Set the Name property of the button as cmdNosList and text

property as “Generate List of Numbers”.

7. Double click the command button and type this code in the

procedure body:

TryLabel3.Text = "List of numbers from " & txtStart.Text & " to " &

txtEnd.Text & " is:" Dim i As Integer

ListBox1.Items.Clear() If CInt(txtStart.Text) > CInt(txtEnd.Text) Then

MsgBox("Start Value must be less than the End Value",MsgBoxStyle.Information, "Enter correct values")

Else For i = CInt(txtStart.Text) To CInt(txtEnd.Text) Step 1

ListBox1.Items.Add("Count " & i)

Next End IfCatch ex As Exception

MsgBox("Enter complete data!", MsgBoxStyle.OKOnly, "Incomplete Data")End Try

8. Code ensures that start value is always less than the endvalue by an if condition.

9. We have also used a try … catch block to encounter anyother error which may halt the program execution.

10.Run application by pressing F5.11.Enter two numbers in the textboxes and press the command

button.12. Desired list of numbers will be obtained in the listbox.

Summing ten consecutive numbers---Using While statement

1. Create a new Windows Application as SquareNum .


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3. Double click the form and type the following code.4. The program generates the list of number counts and also

cumulative sums of the numbers.

Dim start As DoubleDim total As Double = 0Dim count As Integer = 0While count < 10

total += countListBox1.Items.Add("Count = " & count & " , total = " &

total)count += 1

End While

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