Introduction

This is an example of drawing a pie chart in GDI+.

Windows Controls:

• Label
• Button
• Text Box
• Picture Box

1. Start a new Windows Forms Application named SchoolEnrolment2
2. Design the form as follows:
    

   Control Name Text Label   Enrolment / Program Label   Graduates Label   Undergraduates Label   Certificates TextBox txtGraduates 0 TextBox txtUndergraduates 0 TextBox txtCertificates 0 Button btnCreateChart Create Chart PictureBox pbxChart   Label   Legend Label lblGraduates Graduates Label lblUndergraduates Undergraduates Label lblCertificates Certificates Button btnClose Close

3. To design a bitmap, on the main menu, click Project -> Add New Item...
4. In the Templates list, click Bitmap File
5. Change the Name to graduates and click Add
6. To change the file location of the bitmap, on the main menu, click File -> Save graduates.bmp As...
7. Locate and display the SchoolEnrolment2\SchoolEnrolment2\bin\debug folder
8. Click Save
9. In the Solution Explorer, double-click graduates.bmp to make sure it is displayed
10. In the Properties Window, click Width and type 16
11. Click Height and type 16
12. Design the bitmap as follows:
     
    
13. In the Solution Explorer, right-click the Debug folder -> Add -> New Item...
14. In the Templates list, make sure Bitmap File is selected.
    Set the Name to undergraduates and click Add
15. In the Properties window, click Width and type 16
16. Click Height and type 16
17. Design the bitmap as follows:
     
    
18. In the Solution Explorer, right-click the Debug folder -> Add -> New Item...
19. In the Templates list, make sure Bitmap File is selected.
    Set the Name to certificates and click Add
20. In the Properties window, click Width and type 16
21. Click Height and type 16
22. Design the bitmap as follows:
     
    
23. Display the form
24. Right-click the form and click View Code
25. Declare three variables as follows:
    

    Public Class Form1
        Dim Graduates As Single
        Dim Undergraduates As Single
        Dim Certificates As Single
    End Class

26. In the Class Name combo box, select (Form1 Events)
27. In the Method Name combo box, select Paint and implement the event as follows:
    

    Private Sub Form1Paint(ByVal sender As Object, 
                            ByVal e As System.Windows.Forms.PaintEventArgs) 
                            Handles Me.Paint
    
            Dim bmpGraduates As Bitmap = New Bitmap("graduates.bmp")
            Dim BrushGraduates As TextureBrush = 
    		New TextureBrush(bmpGraduates)
            Dim bmpUndergraduates As Bitmap = New Bitmap("undergraduates.bmp")
            Dim brushUndergraduates As TextureBrush = 
    		New TextureBrush(bmpUndergraduates)
            Dim bmpCertificates As Bitmap = New Bitmap("certificates.bmp")
            Dim brushCertificates As TextureBrush = 
    		New TextureBrush(bmpCertificates)
    
            pbxChart.CreateGraphics().FillPie(BrushGraduates, 
                                      0.0F, 0.0F, 
                              260.0F, 200.0F, 0.0F, Graduates)
    
            pbxChart.CreateGraphics().FillPie(brushUndergraduates, 
                                      0.0F, 0.0F, 260.0F, 
                        200.0F, Graduates, Undergraduates)
    
            pbxChart.CreateGraphics().FillPie(brushCertificates, 
                                      0.0F, 0.0F, 260.0F, 
                          200.0F, Graduates + Undergraduates, 
                              Certificates)
    
            e.Graphics.FillRectangle(BrushGraduates, 
                                  New Rectangle(lblGraduates.Left, 
                                lblGraduates.Top + 18, 
                        btnClose.Width, 20))
    
            e.Graphics.DrawRectangle(New Pen(Color.Black), 
                                  New Rectangle(lblGraduates.Left - 1, 
                                lblGraduates.Top + 18, 
                        btnClose.Width, 20))
    
            e.Graphics.FillRectangle(brushUndergraduates, 
                                  New Rectangle(btnClose.Left, 
                                lblUndergraduates.Top + 18, 
                        btnClose.Width, 20))
    
            e.Graphics.DrawRectangle(New Pen(Color.Black), 
                                  New Rectangle(btnClose.Left - 1, 
                                lblUndergraduates.Top + 18, 
                        btnClose.Width + 1, 20))
    
            e.Graphics.FillRectangle(brushCertificates, 
                                  New Rectangle(btnClose.Left, 
                                lblCertificates.Top + 18, 
                        btnClose.Width, 20))
    
            e.Graphics.DrawRectangle(New Pen(Color.Black), 
                                  New Rectangle(btnClose.Left - 1, 
                                lblCertificates.Top + 18, 
                        btnClose.Width + 1, 20))
    
    
            pbxChart.CreateGraphics().DrawPie(New Pen(Color.Blue), 
                                      0.0F, 0.0F, 260.0F, 
                              200.0F, 0.0F, Graduates)
            pbxChart.CreateGraphics().DrawPie(New Pen(Color.Red), 
                                      0.0F, 0.0F, 260.0F, 
                        200.0F, Graduates, Undergraduates)
            pbxChart.CreateGraphics().DrawPie(New Pen(Color.Green), 
                                      0.0F, 0.0F, 260.0F, 
                          200.0F, Graduates + Undergraduates, 
                              Certificates)
    
            pbxChart.CreateGraphics().DrawEllipse(New Pen(Color.Red, 2), 
                                      New Rectangle(0.0F, 0.0F, 260.0F, 200))
    End Sub

28. In the Class Name combo box, select pbxChart
29. In the Method Name combo box, select Paint and implement the event as follows:
    

    Private Sub pbxChartPaint(ByVal sender As Object, 
                             ByVal e As System.Windows.Forms.PaintEventArgs) 
                               Handles pbxChart.Paint
            Invalidate()
        End Sub

30. In the Class Name combo box, select btnCreateChart
31. In the Method Name combo box, select Click and implement the event as follows:
    

    Private Sub btnCreateChartClick(ByVal sender As Object, 
                                         ByVal e As System.EventArgs) 
                                         Handles btnCreateChart.Click
            Dim grad As Single
            Dim under As Single
            Dim cert As Single
            Dim total As Single
            Dim percentGraduates As Single
            Dim percentUndergraduates As Single
            Dim percentCertificates As Single
    
            Try
                grad = CSng(txtGraduates.Text)
            Catch
                MsgBox("Invalid Value")
            End Try
    
            Try
                under = CSng(txtUndergraduates.Text)
            Catch
                MsgBox("Invalid Value")
            End Try
    
            Try
                cert = CSng(txtCertificates.Text)
            Catch
                MsgBox("Invalid Value")
            End Try
    
            total = grad + under + cert
            percentGraduates = (grad / total) * 100
            percentUndergraduates = (under / total) * 100
            percentCertificates = (cert / total) * 100
    
            Graduates = (360 * percentGraduates) / 100
            Undergraduates = (360 * percentUndergraduates) / 100
            Certificates = (360 * percentCertificates) / 100
    
            pbxChart.Invalidate()
    End Sub

32. Execute the application and test the form
     
     
33. After using it, close the form

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