C# 5.0 Programmer's Reference

382 ❘ CHAPTER 16 Printing
When the WpfPrintShapes example program executes, it displays a Print button. When you click the
button, the following code executes.
private void printButton_Click(object sender, RoutedEventArgs e)
{
PrintDialog pd = new PrintDialog();
if (pd.ShowDialog() == true)
{
// Print.
pd.PrintDocument(
new ShapesPaginator(
new Size(pd.PrintableAreaWidth, pd.PrintableAreaHeight)),
"Shapes");
}
}
This code creates a PrintDialog object and calls its ShowDialog method to display it. If the user
selects a printer and clicks Print, the ShowDialog method returns true. In that case, the program calls
the dialog’s PrintDocument method, passing it a new ShapesPaginator object and a description of
the document being printed.
When the program creates the ShapesPaginator object, it passes the constructor a Size structure
representing the page’s printable area.
The ShapesPaginator object does all the interesting work of generating the document’s printed
pages. The following code shows the ShapesPaginator class, except for the GetPage method, which
is described shortly.
public class ShapesPaginator : DocumentPaginator
{
// The area in which to print.
private Size MyPageSize;
// Save the page size.
public ShapesPaginator(Size pageSize)
{
MyPageSize = pageSize;
}
// Create and return the requested page.
public override DocumentPage GetPage(int pageNumber)
{
...
}
// If pagination is in progress and PageCount is not final, return false.
// If pagination is complete and PageCount is final, return true.
// In this example, there is no pagination to do.
public override bool IsPageCountValid
{
get { return true; }
}
// The number of pages paginated so far.
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