lesson 26 Drawing Rectangles

26.1 Creating Rectangles

There are two methods to draw a rectangle on the default form in Visual Basic 2013:

Method 1

Draw a rectangle directly using the DrawRectangle method by specifying its upper-left corner’s coordinate and its width and height. You also need to create a Graphics and a Pen object to handle the actual drawing.The syntax is:

myGrapphics.DrawRectangle(myPen, X, Y, width, height)

*Where myGraphics is the variable name of the Graphics object and myPen is the variable name of the Pen object created by you. X, Y is the coordinate of the upper left corner of the rectangle while width and height are self-explanatory, i.e, the width and height of the rectangle.

The  code

Dim myPen As Pen
 myPen = New Pen(Drawing.Color.Blue, 5)
Dim myGraphics As Graphics = Me.CreateGraphics
 myGraphics.DrawRectangle(myPen, 0, 0, 100, 50)

Method 2

Create a rectangle object first and then draw this triangle using the DrawRectangle method. The syntax is :

myGraphics.DrawRectangle(myPen,myRectangle)

where myRectangle is the rectangle object created by you, the user. The code to create a rectangle object is as shown below:

Dim myRectangle As New Rectangle
 myRect.X = 10
 myRect.Y = 10
 myRect.Width = 100
 myRect.Height = 50

You can also create a rectangle object using a one-line code as follows:

Dim myRectangle As New Rectangle(X,Y,width, height)

and the code to draw the above rectangle is

myGraphics.DrawRectangle(myPen, myRectangle)

26.2 Customizing the Line Style of the Pen Object

The shape we draw so far is drawn with a solid line.  However, we can customize the line style of the Pen object so that we can draw a dotted line, a line consisting of dashes and more. For example, the syntax to draw the dotted line is shown below:

myPen.DashStyle=Drawing.Drawing2D.DashStyle.Dot

Where the last argument Dot specifies a particular line DashStyle value, a line that makes up of dots here. In addition, other DashStyles values are Dash, DashDot, DashDotDot and Solid.The following code draws a rectangle with the blue dotted line.

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim myPen As Pen
 myPen = New Pen(Drawing.Color.Blue, 5)
Dim myGraphics As Graphics = Me.CreateGraphics
 myPen.DashStyle = Drawing.Drawing2D.DashStyle.Dot
 myGraphics.DrawRectangle(myPen, 10, 10, 100, 50)
End Sub

The output image is as  shown in Figure 26.1

If you change the DashStyle value to DashDotDot, you can draw rectangles with different border, as shown in Figure 26.2.

The possible values of the line DashStyle of the Pen are listed in the table below: