The PrintDocument Component

The .NET Framework makes use of the System.Drawing.PrintDocument component (which is based on the PrintDocument class) for printing output, rather than the PrintForm method of the Printers collection used by earlier Microsoft technologies. Managing the PrintDocument component is very similar to the manipulation of other System.Drawing subclass items covered in Chapter 1, "Introducing Windows Forms." Each PrintDocument component creates an event for each page to be printed, and your code is responsible for supplying the text or graphics to be printed on each. The PrintDocument class handles the details of sending this output to your printer, and it automatically adjusts for the printer's capabilities.

After creating a new instance of the PrintDocument class, you will set its properties and then call its Print method, which fires the PrintDocument.PrintPage event. By using methods of the Graphics class, such as the Font and Brush objects, you can paint text and graphics on each page before printing. The order of operations is as follows :

Instantiate a copy of the PrintDocument component in the Windows Form.
Write code within the component's PrintPage event handler that will dictate what is to be printed. At the end of this event, set the HasMorePages property to indicate whether there are more pages to print.
Call the Print method of the PrintDocument object to generate output to the printer.
The BeginPrint method fires once, before the first page of the job prints.
The QueryPageSettings event fires immediately before each PrintPage event, allowing for the manipulation of the value of PrintPageEventArgs.PageSettings before the page is printed.
The PrintPage event fires once for each page to be printed.
The EndPrint event fires once, after the last page of the job has printed.

Printing Text

You can create a sample form that's able to print multiple pages, calculated by the number of lines and the height of the selected font, by performing the following steps:

Open Visual Studio .NET and create a new Visual Basic .NET Windows application with a form.
Place a TextBox control named txtText , a Label control, a NumericUpDown control named nudCopies , a FontDialog control, three Button controls named btnSetFont , btnPageSetup , and btnPrint , and a PrintDocument component on your form (see Figure 11.1).

Figure 11.1. Sample form displaying the controls needed for this example.
Add this code to the top of the form's code module:
```
 Imports System.Drawing.Printing 
```

Add code to handle the events:

 ' Create a default font to print with Dim mfnt As Font = New Font("Arial", 10, FontStyle.Regular, _  GraphicsUnit.Point) ' Number of lines printed so far Dim mintLines As Integer = 0 Private Sub btnPrint_Click(ByVal sender As System.Object, _  ByVal e As System.EventArgs) Handles btnPrint.Click     PrintDocument1.Print() End Sub Private Sub PrintDocument1_PrintPage(ByVal sender As Object, _  ByVal e As System.Drawing.Printing.PrintPageEventArgs) _  Handles PrintDocument1.PrintPage     ' Determine the height of the font     Dim intFontHeight As Integer = mfnt.GetHeight(e.Graphics)     ' Vertical position for the next line of text     Dim intCurrentY As Integer = 0     Dim fPageDone As Boolean = False     Do Until fPageDone         ' Check to see whether there's more space on the page         If intCurrentY <= e.MarginBounds.Height Then             ' Increment the line number             mintLines += 1             If mintLines < nudCopies.Value Then                 ' Print the text, using the selected font                 e.Graphics.DrawString(txtText.Text, mfnt, _                  Brushes.Black, 0, intCurrentY)                 ' And increment the vertical location on the page                 intCurrentY += intFontHeight             Else                 ' We've printed all the copies we need to print. In                 ' this case, set the flags to indicate that this page                 ' is done, but there are no more pages                 fPageDone = True                 e.HasMorePages = False             End If         Else             ' We want to print another line, but there's no space             fPageDone = True             e.HasMorePages = True         End If     Loop End Sub Private Sub btnSetFont_Click(ByVal sender As System.Object, _  ByVal e As System.EventArgs) Handles btnSetFont.Click     ' Start with the current font     FontDialog1.Font = mfnt     ' If the user clicks OK, set a new font     If FontDialog1.ShowDialog = DialogResult.OK Then         mfnt = FontDialog1.Font     End If End Sub Private Sub btnPageSetup_Click(ByVal sender As System.Object, _      ByVal e As System.EventArgs) Handles btnPageSetup.Click     ' Create a PageSettings object and send it to the dialog     Dim pgsCustom As PageSettings = New PageSettings()     PageSetupDialog1.PageSettings = pgsCustom     If PageSetupDialog1.ShowDialog = DialogResult.OK Then      PrintDocument1.DefaultPageSettings = PageSetupDialog1.PageSettings     End If End Sub

Set the form as the startup object and then run the application. After entering some text and manipulating the controls, you can print the result by clicking the Print button. The results will be automatically formatted to fit on separate pages if required by the font and the number of copies of the text specified for printing.

The System.Drawing.Printing.PrintPageEventArgs class is used to provide properties of the printed page, such as the margins and page size, that define the printable area. Table 11.1 presents many of the more common properties of the PrintPageEventArgs class.

Table 11.1. Properties of the PrintPageEventArgs Class

Property	Meaning
Cancel	Gets or sets a value indicating whether the print job should be cancelled
Graphics	A Graphics object representing the page to be printed
HasMorePages	A Boolean value indicating whether there are more pages left
MarginBounds	A rectangle representing the printable area of the page
PageBounds	A rectangle representing the entire page
PageSettings	An object that gets or sets page settings such as orientation

You should be familiar with some of the more common properties of the PageSettings and PrinterSettings classes, as presented in Tables 11.2 and 11.3.

Table 11.2. Properties of the PageSettings Class

Property	Meaning
Bounds	The size of the page based on orientation
Color	Gets or sets a value indicating whether to print in color
Landscape	True if the page is in landscape ( sideways ) orientation
Margins	Gets or sets the margins
PaperSize	Gets or sets the paper size
PaperSource	Gets or sets the paper source
PrinterResolution	Gets or sets the resolution
PrinterSettings	Returns the current PrinterSettings object

Table 11.3. Properties of the PrinterSettings Class

Property	Meaning
CanDuplex	True if the printer supports duplex (two-sided) printing.
Collate	True if the printer output is collated.
Copies	Gets or sets the number of copies to print.
DefaultPageSettings	Returns a PageSettings object for this printer.
Duplex	Gets or sets the duplex setting.
FromPage	Gets or sets the first page number.
InstalledPrinters	Gets the names of all printers on the system.
IsDefaultPrinter	Indicates whether this is the default printer.
IsPlotter	Indicates whether this is a plotter.
IsValid	Indicates whether the PrinterName property designates a valid printer.
LandscapeAngle	The number of degrees of rotation between portrait and landscape output.
MaximumCopies	The maximum number of copies you can print at once.
MaximumPage	The maximum number of pages allowed in the Print dialog box selection.
MinimumPage	The minimum number of pages allowed in a Print dialog box selection.
PaperSizes	Paper sizes supported by this printer.
PaperSources	Paper sources supported by this printer.
PrinterName	Gets or sets the name of the printer to use. Changing this property will change the target printer.
PrinterResolutions	Resolutions supported by this printer.
PrintRange	Page numbers specified for printing.
PrintToFile	True if the output will be sent to a file.
SupportsColor	True if this printer supports color.
ToPage	Gets or sets the last page number to print.

Printing Graphics

It is also possible to print graphic images using the PrintDocument class, as demonstrated in the following example:

Open Visual Studio .NET and create a new Visual Basic .NET Windows application with a form.
Place a Button control named btnPrintGraphics and a PrintDocument component on your form.

Add this code to the top of the form's code module:

 Imports System.Drawing Imports System.Drawing.Printing Imports System.Drawing.Drawing2D

Add code to handle events:

 Private Sub btnPrintGraphics_Click(ByVal sender As System.Object, _  ByVal e As System.EventArgs) Handles btnPrintGraphics.Click     PrintDocument1.Print() End Sub Private Sub PrintDocument1_PrintPage(ByVal sender As Object, _  ByVal e As System.Drawing.Printing.PrintPageEventArgs) _  Handles PrintDocument1.PrintPage     Dim grfx As Graphics = e.Graphics     ' Set the Smoothing mode to SmoothingMode.AntiAlias     grfx.SmoothingMode = SmoothingMode.AntiAlias     ' Create Pen objects     Dim penYellow As Pen = New Pen(Color.Blue, 20)     Dim penRed As Pen = New Pen(Color.Red, 10)     ' Call Draw methods     grfx.DrawLine(Pens.Black, 20, 130, 250, 130)     grfx.DrawEllipse(penYellow, 20, 10, 100, 100)     grfx.DrawRectangle(penRed, 150, 10, 100, 100)     ' No more pages to print     e.HasMorePages = False End Sub

Set the form as the startup object and then run the application. When you click the button, the form will print a rectangle, ellipse, and a line on the output page.

The PrintDocument Component