Print Helper

Article
09/23/2021

The PrintHelper is a class used to simplify document printing. It allows you to render a framework element per page.

To use it, you only have to instantiate a PrintHelper object and call AddFrameworkElementToPrint method to add the XAML controls you want to print. Please note that controls cannot be linked to a visual tree. This means that their parent property has to be null. If you want to use a control from your current XAML page, you can disconnect it before sending it to print (by removing it from its container) or you can create just create a new one from scratch.

Please check the sample app code to see how to disconnect/reconnect a control that you want to print: https://github.com/windows-toolkit/WindowsCommunityToolkit/blob/rel/7.1.0/Microsoft.Toolkit.Uwp.SampleApp/SamplePages/PrintHelper/PrintHelperPage.xaml.cs

Several events are available to control the printing process:

OnPrintFailed will be triggered if the user cancels the print or if something goes wrong
OnPrintSucceeded will be triggered after a successful print
OnPreviewPagesCreated will be triggered after print preview pages are generated. This allows you to control the look and feel of your page before they are sent to the spooler.

In addition, you can customize the printing dialog using the PrintHelperOptions class. To use it, create an instance of the class, add the options you'd like to display on the printing dialog and set the default options. Then, you can use it as a parameter in the PrintHelper class constructor to set them as the default for the instance, or send them as parameters to ShowPrintUIAsync to use them for a single print job.

You can call ShowPrintUIAsync with a second parameter to determine that the list of controls to print should directly be taken from the content of the container passed to the PrintHelper constructor. In this mode you are responsible for the sizing and the layout.

Important

Printing in Dark Theme will likely print white text, which won't be visible. To fix this, ensure the text is a visible color before printing, then restore the original color.

Try it in the sample app

Syntax

var printHelper = new PrintHelper(container);

printHelper.AddFrameworkElementToPrint(frameworkElement);

await printHelper.ShowPrintUIAsync("Title");

Dim printHelper = New PrintHelper(container)

printHelper.AddFrameworkElementToPrint(frameworkElement)

Await printHelper.ShowPrintUIAsync("Title")

Properties

Property	Type	Description
ApplicationContentMarginLeft	double	Gets or sets the percent of app's margin width
ApplicationContentMarginTop	double	Gets or sets the percent of app's margin height

Methods

Methods	Return Type	Description
AddFrameworkElementToPrint(FrameworkElement)	void	Add an element to the list of printable elements
ClearListOfPrintableFrameworkElements()	void	Empties the list of printable elements
Dispose()	void	Release associated resources
RemoveFrameworkElementToPrint(FrameworkElement)	void	Remove an element from the list of printable elements
ShowPrintUIAsync(String, Boolean)	Task	Start the print task

Events

Events	Description
OnPreviewPagesCreated	Event which is called after print preview pages are generated
OnPrintCanceled	Event raised when print is cancelled by the user
OnPrintFailed	Event raised when print failed
OnPrintSucceeded	Event raised when print was successful

Example

// Create a new PrintHelper instance
// "container" is a XAML panel that will be used to host printable control.
// It needs to be in your visual tree but can be hidden with Opacity = 0
var printHelper = new PrintHelper(container);

// Add controls that you want to print
printHelper.AddFrameworkElementToPrint(await PrepareWebViewForPrintingAsync());

// Connect to relevant events
printHelper.OnPrintFailed += PrintHelper_OnPrintFailed;
printHelper.OnPrintSucceeded += PrintHelper_OnPrintSucceeded;

// Start printing process
await printHelper.ShowPrintUIAsync("Windows Community Toolkit Sample App");

// Event handlers

private async void PrintHelper_OnPrintSucceeded()
{
  printHelper.Dispose();
  var dialog = new MessageDialog("Printing done.");
  await dialog.ShowAsync();
}

private async void PrintHelper_OnPrintFailed()
{
  printHelper.Dispose();
  var dialog = new MessageDialog("Printing failed.");
  await dialog.ShowAsync();
}

' Create a new PrintHelper instance
' "container" is a XAML panel that will be used to host printable control. 
' It needs to be in your visual tree but can be hidden with Opacity = 0
Dim printHelper = New PrintHelper(container)
  
' Add controls that you want to print
printHelper.AddFrameworkElementToPrint(Await PrepareWebViewForPrintingAsync())

' Connect to relevant events
printHelper.OnPrintFailed += PrintHelper_OnPrintFailed
printHelper.OnPrintSucceeded += PrintHelper_OnPrintSucceeded

' Start printing process
Await printHelper.ShowPrintUIAsync("Windows Community Toolkit Sample App")

' Event handlers

Private Async Sub PrintHelper_OnPrintSucceeded()
    printHelper.Dispose()
    Dim dialog = New MessageDialog("Printing done.")
    Await dialog.ShowAsync()
End Sub

Private Async Sub PrintHelper_OnPrintFailed()
    printHelper.Dispose()
    Dim dialog = New MessageDialog("Printing failed.")
    Await dialog.ShowAsync()
End Sub

Direct print example:

// Create a new PrintHelper instance
// "container" is a XAML panel that will be used to get the list of printable controls.
var printHelper = new PrintHelper(container);

// Start printing process
await printHelper.ShowPrintUIAsync("Windows Community Toolkit Sample App", true);

' Create a new PrintHelper instance
' "container" is a XAML panel that will be used to get the list of printable controls. 
Dim printHelper = New PrintHelper(container)

' Start printing process
Await printHelper.ShowPrintUIAsync("Windows Community Toolkit Sample App", True)

Using custom default settings:

// Create a new PrintHelperOptions instance
var defaultPrintHelperOptions = new PrintHelperOptions();

//Add options that you want to be displayed on the print dialog
defaultPrintHelperOptions.AddDisplayOption(StandardPrintTaskOptions.Orientation);

//Set preselected settings
defaultPrintHelperOptions.Orientation = PrintOrientation.Landscape;

// Create a new PrintHelper instance
// "container" is a XAML panel that will be used to get the list of printable controls.
var printHelper = new PrintHelper(container, defaultPrintHelperOptions);

' Create a new PrintHelperOptions instance
Dim defaultPrintHelperOptions = New PrintHelperOptions()

' Add options that you want to be displayed on the print dialog
defaultPrintHelperOptions.AddDisplayOption(StandardPrintTaskOptions.Orientation)

' Set preselected settings
defaultPrintHelperOptions.Orientation = PrintOrientation.Landscape

' Create a new PrintHelper instance
' "container" is a XAML panel that will be used to get the list of printable controls.
Dim printHelper = New PrintHelper(container, defaultPrintHelperOptions)

Using custom settings for one print job:

// Create a new PrintHelper instance
// "container" is a XAML panel that will be used to get the list of printable controls.
// "defaultPrintHelperOptions" is a PrintHelperOptions instance that will be used to get the default options for printing.
var printHelper = new PrintHelper(container, defaultPrintHelperOptions);

// Create a new PrintHelperOptions instance
var printHelperOptions = new PrintHelperOptions();

//Add options that you want to be displayed on the print dialog
printHelperOptions.AddDisplayOption(StandardPrintTaskOptions.Orientation);

//Set preselected settings
printHelperOptions.Orientation = PrintOrientation.Landscape;

// Start printing process
await _printHelper.ShowPrintUIAsync("Windows Community Toolkit Sample App", printHelperOptions);

' Create a new PrintHelper instance
' "container" is a XAML panel that will be used to get the list of printable controls.
' "defaultPrintHelperOptions" is a PrintHelperOptions instance that will be used to get the default options for printing.
Dim printHelper = New PrintHelper(container, defaultPrintHelperOptions)

' Create a new PrintHelperOptions instance
Dim printHelperOptions = New PrintHelperOptions()

' Add options that you want to be displayed on the print dialog
printHelperOptions.AddDisplayOption(StandardPrintTaskOptions.Orientation)

' Set preselected settings
printHelperOptions.Orientation = PrintOrientation.Landscape

' Start printing process
Await _printHelper.ShowPrintUIAsync("Windows Community Toolkit Sample App", printHelperOptions)

Print a list with each item on a separate page with static header and page number:

// Create a new PrintHelper instance
// "container" is a XAML panel that will be used to get the list of printable controls.
var printHelper = new PrintHelper(container);

var pageNumber = 0;

foreach (var item in PrintSampleItems)
{
    var grid = new Grid();
    grid.RowDefinitions.Add(new RowDefinition() { Height = GridLength.Auto });
    grid.RowDefinitions.Add(new RowDefinition() { Height = new GridLength(1, GridUnitType.Star) });
    grid.RowDefinitions.Add(new RowDefinition() { Height = GridLength.Auto });

    // Static header
    var header = new TextBlock { Text = "Windows Community Toolkit Sample App - Print Helper - Custom Print", Margin = new Thickness(0, 0, 0, 20) };
    Grid.SetRow(header, 0);
    grid.Children.Add(header);

    // Main content with layout from data template
    var cont = new ContentControl();
    cont.ContentTemplate = Resources["CustomPrintTemplate"] as DataTemplate;
    cont.DataContext = item;
    Grid.SetRow(cont, 1);
    grid.Children.Add(cont);

    // Footer with page number
    pageNumber++;
    var footer = new TextBlock { Text = string.Format("page {0}", pageNumber), Margin = new Thickness(0, 20, 0, 0) };
    Grid.SetRow(footer, 2);
    grid.Children.Add(footer);

    printHelper.AddFrameworkElementToPrint(grid);
}

// Start printing process
await printHelper.ShowPrintUIAsync("Windows Community Toolkit Sample App", printHelperOptions);

  Dim printHelper = New PrintHelper(container)
  Dim pageNumber = 0
  For Each item In PrintSampleItems
      Dim grid = New Grid()
      grid.RowDefinitions.Add(New RowDefinition() With {.Height = GridLength.Auto})
      grid.RowDefinitions.Add(New RowDefinition() With {.Height = New GridLength(1, GridUnitType.Star)})
      grid.RowDefinitions.Add(New RowDefinition() With {.Height = GridLength.Auto})
      Dim header = New TextBlock With {.Text = "Windows Community Toolkit Sample App - Print Helper - Custom Print", .Margin = New Thickness(0, 0, 0, 20)}
      Grid.SetRow(header, 0)
      grid.Children.Add(header)
      Dim cont = New ContentControl()
      cont.ContentTemplate = TryCast(Resources("CustomPrintTemplate"), DataTemplate)
      cont.DataContext = item
      Grid.SetRow(cont, 1)
      grid.Children.Add(cont)
      pageNumber += 1
      Dim footer = New TextBlock With {.Text = String.Format("page {0}", pageNumber), .Margin = New Thickness(0, 20, 0, 0)}
      Grid.SetRow(footer, 2)
      grid.Children.Add(footer)
      printHelper.AddFrameworkElementToPrint(grid)
  Next

  Await printHelper.ShowPrintUIAsync("Windows Community Toolkit Sample App", printHelperOptions)

Sample Project

PrintHelper Sample Page Source. You can see this in action in the Windows Community Toolkit Sample App.

Requirements

Device family	Universal, 10.0.16299.0 or higher
Namespace	Microsoft.Toolkit.Uwp
NuGet package	Microsoft.Toolkit.Uwp

API

Print Helper source code