Printing with VB'Net

1
Printing with VB.Net

• R. Johnson ITE285

2
Windows Graphics

• When your program writes or draws to the screen
  you do not have to worry about the video card or
  monitor specifics.
• This is called device independent graphics.
• Graphics are drawn to a virtual display which
  Windows maps to the actual one using the video
  card driver for your hardware.
• Printing is handled in a similar way. You
  describe a virtual page which is then mapped to
  the actual capabilities (colors, dpi) of the
  printer with its driver.

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Printing Basics

• A PrintDocument serves as the virtual page.
• Its PrintPage event handler is where you write
  the code to draw on the page.
• The Graphics objects methods are used to draw
• .DrawString() for text
• .DrawLine() .DrawImage()
• .DrawRectangle() .DrawEllipse()
  et cetera

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Drawing Details

• DrawString() requires a Font object
• A Font has a name, size and style.
• Drawing colors, fill lines are set with Brushes
• Drawing position is in X-Y coordinates, Y is
  positive down the page.
• Default units are in points (72pts 1inch)

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Printing in Columns

• Easy method
• Pick a fixed pitch (monospaced) font such as
  Courier New. All chars take the same space.
• Pad the output string with the space character,
  easiest with String.Format()
• Alternate method
• Print column items with separate DrawString()
  calls for the same x coordinate.

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String.Format()good for listboxes and printing
columns

• First param is a format string.
• Following params are a list of vars to be
  formatted into the fields.
• Returns a string padded with spaces.
• 0,101,202,15 has field, widthwidth is
  of characters.
• Default is right alignment within field.
• To get left alignment, negative width, ex.
  2,-10

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Printer Dialog Object

• This object connects to the printer driver.
• The PrinterDialog must be associated with the
  PrintDocument object.

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Printer Settings

• The document itself can have virtual settings
  orientation, page size, etc.
• These can be temporarily changed with the Printer
  Dialog

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Printing the Document

• Document is printed with the PrintDocuments
  .Print() method
• Simply drawing past the page bounds causes output
  to span to another page during printing.
• Managing multiple pages for repeating headers,
  etc. is more complex.

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Print Preview

• The PrintPreview Dialog is a virtual printer.
• Printed output can be viewed on the display. You
  can then print on the printer.