Working with Forms 

Well, let's now start working with Forms. When you open a new form you can have a look at the default properties of the form by selecting View->Properties Window or by pressing F4 on the keyboard. The properties window opens with default properties set to form by the software.

Briefly on Properties (Categorized):

Appearance

Appearance section of the properties window allow us to make changes to the appearance of the form. With the help of appearance properties we can have a background color, background image for the entire form, set the border style for the form from a predefined list, change the cursor, set the font for the text on the form and so on.

Behavior

Notable Behavior property is the enabled property which lets us enable/disable the form by setting the property to True/False.

Layout

Layout properties are all about the structure of the form. With these properties we can set the location of the form, maximum size of the form, minimum size of the form, exact size of the form with the size property when designing. Note the property start position, this property lets you specify the location of the form where it should appear when you run the application which you can select from a predefined list.

Window Style

The notable property under this is the ControlBox property which by default it is set to True. Setting the property to False makes the minimize, maximize and cancel buttons on the top right side of the form invisible.

Form Event

The default event of a form is the load event which looks like this in code:

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs)_ Handles MyBase.Load End Sub

You can write code in the load event of the form just like you write for all other controls.

An Example:

You can run the Form by selecting Debug->Start from the main menu or by pressing F5 on the keyboard. When you run a blank form with no controls on it, nothing is displayed. It looks like the image below.

Now, add a TextBox and a Button to the form from the toolbox. The toolbox can be selected from
View->ToolBox on the main menu or by holding Ctrl+Alt+X on the keyboard. Once adding the TextBox and Button is done, run the form. The output window displays a TextBox and a Button. When you click the Button nothing happens. We need to write an event for the Button stating something should happen when you click it. To do that get back to design view and double-click on the  Button. Doing that opens an event handler for the Button where you specify what should happen when you click the button. That looks like this in code.

Public Class Form1 Inherits System.Windows.Forms.Form #Region " Windows Form Designer generated code " Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs)_ Handles MyBase.Load End Sub Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As _ System.EventArgs) Handles Button1.Click End Sub End Class

Place the code TextBox1.Text="Welcome to Forms" in the Click event of the Button and run the application. When you click the Button the output "Welcome to Forms" is displayed in the TextBox.

Alternatively, you can also use the MsgBox or MessageBox functions to display text when you click on the Button. To do that place a Button on the form and double-click on that to open it's event. Write this line of code, MsgBox("Welcome to Forms") or MessageBox.Show("Welcome to Forms").

It looks like this in code.

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As _ System.EventArgs) Handles Button1.Click MsgBox("Welcome to Forms") End Sub or Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As _ System.EventArgs) Handles Button1.Click MessageBox.Show("Welcome to Forms") End Sub

When you run the form and click the Button, a small message box displays, "Welcome to Forms". The image below displays that.

Next>> Adding a New Form, Working with Multiple Forms, Visual Inheritance