Simple Colored Brushes

Imports System.Drawing
Imports System.Windows.Forms

Module Exercise

    Public Class Starter
        Inherits Form

        Dim components As System.ComponentModel.Container

        Public Sub New()
            InitializeComponent()
        End Sub

        Public Sub InitializeComponent()

        End Sub

        Private Sub FormPaint(ByVal sender As Object, _
                              ByVal e As PaintEventArgs) _
                              Handles MyBase.Paint

            Dim pt As Point() = { _
 		New Point(10, 22), _
 		New Point(188, 246), _
                          	New Point(280, 192), _
 		New Point(250, 48)}

            e.Graphics.FillClosedCurve(Brushes.BlanchedAlmond, pt)
            e.Graphics.DrawClosedCurve(Pens.Blue, pt)

        End Sub
    End Class

    Function Main() As Integer

        Dim frmStart As Starter = New Starter

        Application.Run(frmStart)

        Return 0
    End Function

End Module

This would produce:

The simplest type of brush is referred to as solid. This type of brush is simply equipped with a color and it is used to fill a shape with it. To get a solid brush, you use the SolidBrush class defined in the System.Drawing namespace. It has only one constructor declared with the following syntax:

Public Sub New(color As Color)

The color passed as argument must be a valid definition of a Color. Here is an example:

Private Sub FormPaint(ByVal sender As Object, _
                              ByVal e As PaintEventArgs) _
                              Handles MyBase.Paint

            Dim brushBlue As SolidBrush = New SolidBrush(Color.Blue)

            e.Graphics.FillRectangle(brushBlue, 20, 20, 200, 160)

End Sub

This would produce:

If you plan to use different colors to fill different shapes, you don't have to create a new brush for each shape. At any time, before re-using the same brush previously defined, you can simply change its Color. For this reason, the SolidBrush class is equipped with the Color property. Here is an example of using it:

Private Sub FormPaint(ByVal sender As Object, _
                              ByVal e As PaintEventArgs) _
                              Handles MyBase.Paint

            Dim colorizer As SolidBrush = New SolidBrush(Color.Lime)
            e.Graphics.FillRectangle(colorizer, 10, 10, 120, 120)

            colorizer.Color = Color.Salmon
            e.Graphics.FillRectangle(colorizer, 140, 10, 120, 120)

            colorizer.Color = Color.Aqua
            e.Graphics.FillRectangle(colorizer, 10, 140, 120, 120)

            colorizer.Color = Color.Navy
            e.Graphics.FillRectangle(colorizer, 140, 140, 120, 120)

End Sub

This would produce:

Like most objects used in graphics programming, a brush consumes the computer resources. Therefore, after using it, you can free the resources it was using by calling the Dispose() method. Here is an example:

Private Sub FormPaint(ByVal sender As Object, _
                              ByVal e As PaintEventArgs) _
                              Handles MyBase.Paint

            Dim colorizer As SolidBrush = New SolidBrush(Color.Lime)
            e.Graphics.FillRectangle(colorizer, 10, 10, 120, 120)

            colorizer.Color = Color.Salmon
            e.Graphics.FillRectangle(colorizer, 140, 10, 120, 120)

            colorizer.Color = Color.Aqua
            e.Graphics.FillRectangle(colorizer, 10, 140, 120, 120)

            colorizer.Color = Color.Navy
            e.Graphics.FillRectangle(colorizer, 140, 140, 120, 120)

            colorizer.Dispose()
End Sub