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Printing in WPF

Printing FlowDocument in WPF

This article demonstrates how to create a FlowDocument dynamically and print it in WPF.

Introduction

Printing in WPF has changed drastically in WPF. If are experienced with writing printing applications using GDI or GDI+, you will have to start thinking differently. Now, you have to think of a FlowDocument. If you want to print in WPF, what you actually need to do is, create a FlowDocument object, add your contents that you would like to print to this FlowDocument and send this FlowDocument object to the printer.

Before you write your printing code, you must make sure you import these two namespaces in your project.

  1. using System.Printing;  
  2.   
  3. using System.Windows.Documents; 

The System.Windows.Documents namespace is already added to your project when you create a new WPF project. The System.Printing namespace is required for the printing functionality.

Printing Process

OK, here are the steps required to print a FlowDocument in WPF.

1. Create a PrintDialog

The following code creates a PrintDialog in WPF code.

  1. // Create a PrintDialog  
  2.   
  3. PrintDialog printDlg = new PrintDialog(); 

2. Create a FlowDocument

The FlowDocument object is used to create a FlowDocument. It has items such as a paragraph, run, line, image and so on. The following code snippet creates a FlowDocument and adds a line of text to the document.

  1. // Create a FlowDocument dynamically.  
  2.   
  3. FlowDocument doc = new FlowDocument(new Paragraph(new Run("Some text goes here")));  
  4.   
  5. doc.Name = "FlowDoc";

3. Create an IDocumentPaginatorSource

The third step is to create an IDocumentPaginatorSource object from a FlowDocument that is pretty simple as listed here. You directly convert a FlowDocument to an IDocumentPaginatorSource.

  1. // Create IDocumentPaginatorSource from FlowDocument  
  2.   
  3. IDocumentPaginatorSource idpSource = doc;  

4. Call PrintDialog.PrintDocument method

The last step is to call PrintDialog.PrintDocument method to call the print dialog that will allow you to select a printer and send document to the printer to print it. The PrintDocument method of PrintDialog takes a DocumentPaginator object that you can get from IDocumentPaginatorSource.DocumentPaginator property as listed in the following code:

  1. // Call PrintDocument method to send document to printer  
  2.   
  3. printDlg.PrintDocument(idpSource.DocumentPaginator, "Hello WPF Printing."); 

The Application

Ok now you know what is required to print FlowDocuments in WPF, let's create a working application. Create a WPF Application and add a Button control to the Window.  

After that, change the Name attribute of the button to PrintSimpleTextButton and double click on it to write a button click event handler. My XAML code of MainWindow looks like Listing 1.

  1. <Window x:Class="PrintingTextSample.MainWindow"     xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"  
  2.         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"  
  3.         Title="MainWindow" Height="350" Width="525">  
  4.     <Grid>  
  5.         <Button Content="Print Simple Text" Height="37" HorizontalAlignment="Left" Margin="22,21,0,0"  
  6.                 Name="PrintSimpleTextButton" VerticalAlignment="Top" Width="134"  
  7.                 Click="PrintSimpleTextButton_Click" />  
  8.     </Grid>  
  9. </Window>

Listing 1

Now I am going to create a FlowDocument in WPF. The CreateFlowDocument method in Listing 2 creates and returns a FlowDocument object. The Paragraph, Section, Underline objects represent a paragraph, section, and underline of a document. You can add as many contents to your FlowDocument here. I am writing a tutorial on working with FlowDocuments in WPF. Stay tuned for it.

  1. /// <summary>  
  2. /// This method creates a dynamic FlowDocument. You can add anything to this  
  3. /// FlowDocument that you would like to send to the printer  
  4. /// </summary>  
  5. /// <returns></returns>  
  6. private FlowDocument CreateFlowDocument()  
  7. {  
  8.     // Create a FlowDocument  
  9.     FlowDocument doc = new FlowDocument();  
  10.     // Create a Section  
  11.     Section sec = new Section();  
  12.     // Create first Paragraph  
  13.     Paragraph p1 = new Paragraph();  
  14.     // Create and add a new Bold, Italic and Underline  
  15.     Bold bld = new Bold();  
  16.     bld.Inlines.Add(new Run("First Paragraph"));  
  17.     Italic italicBld = new Italic();  
  18.     italicBld.Inlines.Add(bld);  
  19.     Underline underlineItalicBld = new Underline();  
  20.     underlineItalicBld.Inlines.Add(italicBld);  
  21.     // Add Bold, Italic, Underline to Paragraph  
  22.     p1.Inlines.Add(underlineItalicBld);  
  23.     // Add Paragraph to Section  
  24.     sec.Blocks.Add(p1);  
  25.     // Add Section to FlowDocument  
  26.     doc.Blocks.Add(sec);  
  27.     return doc;  
  28. } 

Listing 2

Now, we are going to write code on the button click event handler that will create a FlowDocument and print it.

As you can see from the code listed in Listing 3, we follow the steps discussed in the previous section. I first create a PrintDialog, then create a FlowDocument, convert it to an IDocumentPaginatorSource and in the end, call PrintDialog.PrintDocument method.

  1. private void PrintSimpleTextButton_Click(object sender, RoutedEventArgs e)  
  2. {  
  3.     // Create a PrintDialog  
  4.     PrintDialog printDlg = new PrintDialog();  
  5.     // Create a FlowDocument dynamically.  
  6.     FlowDocument doc = CreateFlowDocument();  
  7.     doc.Name = "FlowDoc";  
  8.     // Create IDocumentPaginatorSource from FlowDocument  
  9.     IDocumentPaginatorSource idpSource = doc;  
  10.     // Call PrintDocument method to send document to printer  
  11.     printDlg.PrintDocument(idpSource.DocumentPaginator, "Hello WPF Printing.");  
  12. }

 Listing 3

Print a Control, User Control or a Window in WPF

In WPF, a Visual is an object that is parent class of all user interfaces including UIElement, Containers, Controls, UserControls, and even Viewport3DVisual. If you notice all control or user controls classes, they are inherited from a UIElement class.

The PrintVisual print a Visual object. That means, by using the PrintVisual method, we can print any control, container, Window or user control.

The following code snippet in creates a PrintDialog object and calls its PrintVisual method by passing a UserControl to print the UserControl. Using this method, we can print any controls in WPF including a Window, page, or a ListBox.

  1. PrintDialog printDlg = new PrintDialog();  
  2. UserControl1 uc = new UserControl1();  
  3. printDlg.PrintVisual(uc, "User Control Printing."); 

What if you want to print a Grid control or any other control?

As said above, printing any control in WPF is same process. Just pass the Grid or other control in the PrintVisual method of PrintDialog.

  1. PrintDialog printDlg = new PrintDialog();  
  2. printDlg.PrintVisual(grid1, "Grid Printing."); 

How about printing the entire Window?

For entire window, you can either pass the window object or this keyword. This time, you pass "this" that is the object of current Window where you are writing this code.

  1. PrintDialog printDlg = new PrintDialog();  
  2. printDlg.PrintVisual(this, "Window Printing.");  

Summary

In this article, I demonstrated how to create a FlowDocument object dynamically and send it to a printer to print it by using a PrintDialog control available in WPF.

Further Readings

Here are some more WPF and Windows Forms Printing related articles.


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