VB.Net Tutorial/2D Graphics/Ruler

Ruler

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
#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
#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