Dynamically set page size when printing from VB.NET

irlrobins

Hey all,

I'm trying to get this working but so far without luck. I'm developing an ap in VB.net that part of which takes an image file (.jpg), annotates it with some text and prints the output. Depending on the size of the image, it should print to either A4 or A3. Everything works apart from the page sizing. A print job that I expect to print on A3 prints on A4 and isn't scaled to fit so only a portion of the image is printed.

Anyone got any ideas?

Code follows:

Main code:

Private WithEvents PD As PrintDocument
     PD = New PrintDocument
                    PD.PrinterSettings.PrinterName = "Printer name"
                    Dim bm As New Bitmap(path to original image file)
                    bm2 = New Bitmap(bm.Width, bm.Height) 'create new bitmap for edited image
                    bm2.SetResolution(bm.HorizontalResolution, bm.VerticalResolution)
                    Dim pageSize As String = DeterminePageSize(bm2.Width, bm2.Height)
                    Dim pageOrientation As String = DetermineOrientation(bm2.Width, bm2.Height, pageSize)
                    If pageOrientation = "Landscape" Then
                        PD.DefaultPageSettings.Landscape = True
                    Else
                        PD.DefaultPageSettings.Landscape = False
                    End If
                    If pageSize = "A3" Then
                        PD.DefaultPageSettings.PaperSize = New System.Drawing.Printing.PaperSize("A3", 1169, 1654)
                    Else
                        PD.DefaultPageSettings.PaperSize = New System.Drawing.Printing.PaperSize("A4", 830, 1170)
                    End If

                    Using gr As Graphics = Graphics.FromImage(bm2)
                        gr.DrawImage(bm, 0, 0, bm.Width, bm.Height) 'copy image from original
      'more code here that adds some text to the new bitmap etc
                        
                    End Using
                    PD.DefaultPageSettings.Margins = New Printing.Margins(40, 40, 40, 40)
                    PD.OriginAtMargins = True
                    PD.Print() ' print the image
                    'clear up
                    'bm2.Save("new filename", System.Drawing.Imaging.ImageFormat.Jpeg)  --used for debugging only
                    bm.Dispose()
                    bm2.Dispose()
                    PD.Dispose()

Functions to determine orientation and size based on original image size:

Private Function DeterminePageSize(ByVal x As Integer, ByVal y As Integer) As String
        If (x <= 210 And y <= 297) Or (x <= 297 And y <= 210) Then
            Return "A4"
        Else
            Return "A3"
        End If
    End Function
 
 Private Function DetermineOrientation(ByVal x As Integer, ByVal y As Integer, ByVal PageSize As String) As String
        If PageSize = "A4" Then
            If (x > 210 And x > y) Then
                Return "Landscape"
            Else
                Return "Portrait"
            End If
        Else
            If (x > 297 And x > y) Then
                Return "Landscape"
            Else
                Return "Portrait"
            End If
        End If
    End Function

This sub should scale image to fit in the printable area of the page

Private Sub FitPictureToMargins(ByVal gr As Graphics, ByVal picture_bounds As RectangleF, ByVal margin_bounds As RectangleF)
        ' Remove any existing transformation.
        gr.ResetTransform()
        ' Translate to center picture_bounds at the origin.
        gr.TranslateTransform( _
            -(picture_bounds.Left + picture_bounds.Width / 2), _
            -(picture_bounds.Top + picture_bounds.Height / 2))
        ' Scale to make picture_bounds fit margin_bounds.
        ' Compare the aspect ratios.
        Dim margin_aspect As Single = margin_bounds.Height / margin_bounds.Width
        Dim picture_aspect As Single = picture_bounds.Height / picture_bounds.Width
        Dim scale As Single
        If picture_aspect > margin_aspect Then
            ' picture_bounds is relatively tall and thin.
            ' Make it as tall as possible.
            scale = margin_bounds.Height / picture_bounds.Height
        Else
            ' picture_bounds is relatively short and wide.
            ' Make it as wide as possible.
            scale = margin_bounds.Width / picture_bounds.Width
        End If
        ' Scale.
        gr.ScaleTransform(scale, scale, MatrixOrder.Append)
        ' Translate to move the origin to the center of margin_bounds.
        gr.TranslateTransform( _
            margin_bounds.Left + margin_bounds.Width / 2, _
            margin_bounds.Top + margin_bounds.Height / 2, _
            MatrixOrder.Append)
    End Sub

irlrobins

Turns out my code was working fine and the printer was the issue. It wasn't correctly configured to handle A3 so kept trying to revert to printing on A4. Tested on a correctly configured printer and all is well.