Visual Basic 2010 Lesson 22 – The DrawRectangle Method

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22.1 Creating a Rectangle with DrawRectangle Method

There are two methods to draw a rectangle on the screen in VB2010:

Method 1

Use the DrawRectangle method by specifying its upper-left corner’s coordinate and it 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)



*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.

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 rectangle using the DrawRectangle method. The syntax is as shown below:

myGraphics.DrawRectangle(myPen,myRectangle)

where myRectangle is the rectangle object created by you, the user.

The code is:

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)

The sample code is shown below:

22.2 Customizing Line Style of the Pen Object

The shape we draw so far are drawn with a solid line, we can actually customize the line style of the Pen object so that we have dotted line, a line consisting of dashes and more. For example, the syntax to draw a 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. The following code draws a rectangle with the red 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.Red, 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 shown below:

Visual Basic 2010



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

Visual Basic 2010




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