Just to finish it off, the names of the countries are written below each bar.

  This is very similar to what we did in Part 2, with the addition of a code line that adjusts the font size according to the width available.

   Private Sub WriteTheNames()
        '  X position for start of country name(s).  It is placed
        '  under the left edge of the bar, plus 5 pixels for better look
        Dim TextStartX As Integer = LeftMargin + BarGap + 5

        '  Create a Brush to draw the text
        Dim TextBrsh As Brush = New SolidBrush(Color.Black)
        '  Create a Font object instance for text display
        '  dynamically adjusted font size would be useful:
        Dim fntSize As Integer = CInt(BarWidth / 7)
        Dim TextFont As New Font("Verdana", fntSize, FontStyle.Bold)
        '   Write them:
        For Each gd As GraphData In SalesData
            g.DrawString(gd.Country, TextFont, TextBrsh, TextStartX, CInt(PBBarChart.Height - (BaseMargin - 4)))
            TextStartX += CInt(BarWidth + BarGap)
        Next
    End Sub

Again, you will need to add a call to this procedure in the Draw Button’s click event.  The complete code for that event would therefore look like this:

  Private Sub btnDraw_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnDraw.Click
        '  The various actions are now split into separate procedures to make
        '  the project more modular

        '  1.  Get the data
        GetData()
        '  2.  Get a Graphics object
        g = GetGraphics()
        '  3.   Draw the Vertical Axis
        DrawVerticalAxis(g)
        '  4.  Draw bars
        Draw3DBars()
        '  5.  Write the titles
        WriteTheNames()
        ' All Done!   Assign the bitmap with the vertical axis drawn to the picturebox
        pbBarChart.Image = bmap
  g.Dispose()
    End Sub