VB.Net Tutorial/2D Graphics/Ruler

Ruler

<source lang="vbnet">Imports System.Drawing Imports System.Drawing.Drawing2D Imports System.Windows.Forms public class MatrixMarginsDemo

  public Shared Sub Main
       Application.Run(New MatrixMarginsForm)
  End Sub

End class

Public Class MatrixMarginsForm

   Inherits System.Windows.Forms.Form

1. Region " Windows Form Designer generated code "

   Public Sub New()
       MyBase.New()
       "This call is required by the Windows Form Designer.
       InitializeComponent()
       "Add any initialization after the InitializeComponent() call
   End Sub
   "Form overrides dispose to clean up the component list.
   Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
       If disposing Then
           If Not (components Is Nothing) Then
               components.Dispose()
           End If
       End If
       MyBase.Dispose(disposing)
   End Sub
   "Required by the Windows Form Designer
   Private components As System.ruponentModel.IContainer
   "NOTE: The following procedure is required by the Windows Form Designer
   "It can be modified using the Windows Form Designer.  
   "Do not modify it using the code editor.
   Friend WithEvents statusBar1 As System.Windows.Forms.StatusBar
   <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
       Me.statusBar1 = New System.Windows.Forms.StatusBar()
       Me.SuspendLayout()
       "
       "statusBar1
       "
       Me.statusBar1.Location = New System.Drawing.Point(0, 244)
       Me.statusBar1.Name = "statusBar1"
       Me.statusBar1.Size = New System.Drawing.Size(292, 22)
       Me.statusBar1.TabIndex = 1
       Me.statusBar1.Text = "statusBar1"
       "
       "MatrixMarginsForm
       "
       Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
       Me.ClientSize = New System.Drawing.Size(292, 266)
       Me.Controls.AddRange(New System.Windows.Forms.Control() {Me.statusBar1})
       Me.Name = "MatrixMarginsForm"
       Me.Text = "MatrixMarginsForm"
       Me.ResumeLayout(False)
   End Sub

1. End Region

   Private Function InchesToPixels(ByVal inches As Single) As Single
       Dim g As Graphics = Me.CreateGraphics()
       Return inches * g.DpiY
   End Function
   Function InchesToPixels(ByVal rect As RectangleF) As RectangleF
       Return New RectangleF(InchesToPixels(rect.X), InchesToPixels(rect.Y), InchesToPixels(rect.Width), InchesToPixels(rect.Height))
   End Function
   Function PixelsToInches(ByVal pixels As Single) As Single
       Dim g As Graphics = Me.CreateGraphics
       Return pixels / g.DpiY
   End Function
   Sub PaintInInches(ByVal g As Graphics)
       Dim matrix As Matrix = New Matrix()
       matrix.Scale(g.DpiX, g.DpiY)
       g.Transform = matrix
       Dim rulerFont As Font = New Font("MS Sans Serif", 8.25F / g.DpiY)
       Dim blackPen As Pen = New Pen(Color.Black, 0)
       Dim rulerFontHeight As Single = rulerFont.GetHeight(g)
       Dim rulerRect As RectangleF = New RectangleF(0, 0, 6.5F, rulerFontHeight * 1.5F)
       g.DrawRectangle(blackPen, rulerRect.X, rulerRect.Y, rulerRect.Width, rulerRect.Height)
       Dim i As Single
       For i = 1 To 6
           Dim rect As RectangleF = New RectangleF(i - rulerFontHeight, 0, rulerFontHeight * 2, rulerFontHeight)
           Dim format As StringFormat = New StringFormat()
           format.Alignment = StringAlignment.Center
           g.DrawString(i.ToString(), rulerFont, Brushes.Black, rect, format)
       Next
       For i = 0.5 To 6.5 Step 1
           g.DrawLine(blackPen, i, 0, i, rulerFontHeight / 2)
       Next
   End Sub
   Sub Margins_Paint(ByVal sender As Object, ByVal e As PaintEventArgs) Handles MyBase.Paint
       PaintInInches(e.Graphics)
       ShowClientSize()
   End Sub
   Sub ShowClientSize()
       Dim g As Graphics = Me.CreateGraphics
       Dim matrix As Matrix = New Matrix()
       matrix.Scale(g.DpiX, g.DpiY)
       g.Transform = matrix
       Dim bottomRight As PointF() = New PointF() {New PointF(Me.ClientSize.Width, Me.ClientSize.Height)}
       g.TransformPoints(CoordinateSpace.World, CoordinateSpace.Device, bottomRight)
       statusBar1.Text = String.Format("ClientSize= {0} pixels, {1} inches", Me.ClientSize, bottomRight(0))
   End Sub
   Sub MarginsForm_Resize(ByVal sender As Object, ByVal e As EventArgs) Handles MyBase.Resize
       Me.Invalidate()
   End Sub

End Class</source>