Wednesday, February 25, 2009

Making Different Applications

Making Different Applications
Creating an application in Visual Basic is simple. You have already learnt a lot about creating a VISUAL BASIC application. Now it will take just a minute to create your first VISUAL BASIC application.
First of all let us make a Simple 'Hello' application, As we do in other programming language:
Hello Visual Basic Application:

The first step in building a Visual Basic application is to create the forms that will be the basis for your application's interface. Then you draw the objects that make up the interface on your forms. For this first application, you will use two controls from the Toolbox.
1. Click tool Box for the control you choose to draw - In this case, the text box. Move the pointer onto your form. The pointer becomes a cross hair.
2. Place the cross hair where you want the the control.
3. Drag the cross hair until the control is the size you want.
4. Release the mouse button.
Form will look like the figure:
For the "Hello, VB!" example, you will need to change three property settings. Use the default settings for all other properties:
Object Property Setting
Form Caption Hello VB
Command Button Caption OK
Textbox Text (Empty)
After property setting form will look like:
Writing Code:
1. For this example, choose the command button, Command1.
2. In the Procedure list box, select the name of an event for the selected object:
Here, the Click procedure is already selected, because it's the default procedure for a command button.
Type the following code between the Sub and End Sub statements:
Text1.Text = "Hello, VB!"
The event procedure will look like this:
Private Sub Command1_Click ()
Text1.Text = "Hello, VB!"
End Sub
Running the Application
To run the application, choose Start from the Run menu, or click the Start button on the toolbar, or press F5. Click command button you have created on the form and you will see "Hello,VB!" displayed in text box.
An application using Mathematical Operations
For Animated Presentation Click Here
Now you will create an application which performs two operations:
1. ADD

2. MULTIPLY
Designing the interface
1. Select a New project from file menu,then select standard EXE.
2. Place controls in the form to create the user interface according to the figure:
3. Now for above example, you will need to change different property settings. Change the properties according to the figure:
Use the default settings for all other properties.
Property Table:
Object Property Setting
Form Caption Mathematical Calculations
Command Button1 Caption ADD
Command Button2 Caption MULTIPLY
Command Button3 Caption EXIT
Textbox1 Text (Empty)
Textbox2 Text (Empty)
Textbox3 Text (Empty)
Label1 Caption 1st Number
Label2 Caption 2nd Number
Label3 Caption Result
After setting the properties for different controls the form will look like figure:
Coding:
1. Double click on the command button ADD.
Private Sub Command1_click( )
Dim No1 As Integer
Dim No2 As Integer
No1=Text1.Text
No2=Text2.Text
Text3.Text=No1+No2
End Sub
Dim' statement in VISUAL BASIC is used to declare variables.
The 1st two lines of code declare two variables named No1 and No2 , as integer.
Then further lines of code are used to store the values entered by user in the two text boxes into the variables just declared
The last line of code adds up the two values and displays them in textbox3.
2. For multiplication of two numbers, write following code by the Clicking on Multiply button.
Private Sub Command1_click( )
Dim No1 As Integer
Dim No2 As Integer
No1=Text1.Text
No2=Text2.Text
Text3.Text=No1*No2
End Sub
3. For exiting ,type the following code to the Click event of 'Command3'.
Private Sub Command3_click( )
End
End Sub
Now the Code Window will look like the figure:
Running the Application:
1. Press F5 or Select Run from menu.
2. Now the project will run and the form will appear. Click in the text box1 and enter 10.
3. Click in the text box2 and enter 5.
4. Click on the button ADD,the result will be displayed in the result textbox.
5. Click on the button MULTIPLY, the result will be displayed in the result textbox.
Following figure is showing addition of two numbers:
6. Click on the button EXIT to close the application.

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