How to Print with a Dialog in C#

How Does the Print Dialog Work in C#?

The Printer.ShowPrintDialog() method opens the operating system's native print dialog. The user sees the full set of print options — printer selection, number of copies, page range, orientation, and paper size — and clicks Print to send the job, or Cancel to dismiss the dialog without printing.

Under the hood, the native .NET approach requires creating a System.Windows.Forms.PrintDialog instance, wiring it to a PrintDocument, handling the PrintPage event to draw content onto the print graphics surface, checking the DialogResult, and then calling PrintDocument.Print(). That setup typically runs 15–25 lines of code. It also does not include built-in PDF or image rendering — printing a PDF through the native dialog means first parsing the PDF into drawable pages, which requires yet another library.

IronPrint handles the entire pipeline in one call:

:path=/static-assets/print/content-code-examples/how-to/print-with-dialog/show-print-dialog-open-and-print.cs

using IronPrint;

// Open the dialog, let the user configure settings, and print
Printer.ShowPrintDialog("quarterly-report.pdf");

Imports IronPrint

' Open the dialog, let the user configure settings, and print
Printer.ShowPrintDialog("quarterly-report.pdf")

The method accepts a file path as a string or raw file data as a byte[]. IronPrint detects the document format, renders it through the appropriate engine, and presents the dialog. When the user confirms, the document prints with their chosen settings. The print document tutorial walks through the full printing lifecycle in more detail.

How Do I Pre-Configure Dialog Settings?

We can set default values before the dialog opens by creating a PrintSettings object and passing it as the second parameter. The dialog will open with these values pre-selected, and the user can accept them as-is or override any setting.

:path=/static-assets/print/content-code-examples/how-to/print-with-dialog/preconfigure-dialog-settings.cs

using IronPrint;

// Pre-configure defaults for the dialog
var settings = new PrintSettings
{
    PrinterName = "HP LaserJet Pro",
    PaperSize = PaperSize.A4,
    PaperOrientation = PaperOrientation.Portrait,
    Dpi = 300,
    NumberOfCopies = 2,
    Grayscale = false
};

// Open dialog with pre-filled settings
Printer.ShowPrintDialog("invoice.pdf", settings);

Imports IronPrint

' Pre-configure defaults for the dialog
Dim settings As New PrintSettings With {
    .PrinterName = "HP LaserJet Pro",
    .PaperSize = PaperSize.A4,
    .PaperOrientation = PaperOrientation.Portrait,
    .Dpi = 300,
    .NumberOfCopies = 2,
    .Grayscale = False
}

' Open dialog with pre-filled settings
Printer.ShowPrintDialog("invoice.pdf", settings)

This is useful when the application knows the likely printer or paper format in advance. For example, a point-of-sale system that always prints receipts on a specific thermal printer can default PrinterName to that device. The user still has the option to change it in the dialog.

To discover which printers are available on the system, we call Printer.GetPrinterNames(), which returns a List<string> of all installed printers. Similarly, Printer.GetPrinterTrays() returns available paper trays for a given printer.

The full list of configurable properties includes PrinterName, PaperSize, PaperOrientation, Dpi, NumberOfCopies, Grayscale, PaperMargins, Flatten (for PDF form fields), and Tray. The print settings how-to covers each property with code examples. Any property not set in PrintSettings defaults to the selected printer's standard configuration.

How Do I Show the Dialog Asynchronously?

The Printer.ShowPrintDialogAsync() method returns a Task, making it compatible with async/await. This prevents the dialog from blocking the UI thread — essential for WPF, MAUI, and any application where a frozen interface creates a poor user experience.

:path=/static-assets/print/content-code-examples/how-to/print-with-dialog/show-print-dialog-async.cs

using IronPrint;

// Non-blocking dialog — the UI remains responsive
await Printer.ShowPrintDialogAsync("report.pdf");

Imports IronPrint

' Non-blocking dialog — the UI remains responsive
Await Printer.ShowPrintDialogAsync("report.pdf")

ShowPrintDialogAsync() accepts the same parameters as the synchronous version: a file path or byte array, plus an optional PrintSettings object. The async pattern follows the same Task-based Asynchronous Pattern used throughout modern .NET development.

IronPrint works across WinForms, WPF, MAUI, and console applications. The dialog appearance adapts to the host platform and OS version, so the user always sees the native print window they expect.

When Should I Use a Dialog vs. Silent Printing?

The choice depends on whether the user needs control over the print job.

Use the dialog when users need to verify or change settings before printing — report exports, invoice prints, or any scenario where the wrong printer causes a wasted page. Use silent printing when the application controls the entire job and no human decision is needed. The print document tutorial demonstrates both approaches side by side.

What File Formats Does the Print Dialog Support?

Printer.ShowPrintDialog() supports the same formats as silent printing: PDF, PNG, TIFF, JPEG, GIF, HTML, and BMP. We pass the file path regardless of format, and IronPrint handles rendering and print spooler communication. File data as a byte[] is also accepted, which is useful when the document is generated in memory or retrieved from a database.

:path=/static-assets/print/content-code-examples/how-to/print-with-dialog/print-dialog-image-and-byte-array.cs

using IronPrint;

// Print an image with the dialog
Printer.ShowPrintDialog("product-photo.png");

// Print from a byte array
byte[] reportData = File.ReadAllBytes("monthly-report.pdf");
Printer.ShowPrintDialog(reportData);

Imports IronPrint

' Print an image with the dialog
Printer.ShowPrintDialog("product-photo.png")

' Print from a byte array
Dim reportData As Byte() = File.ReadAllBytes("monthly-report.pdf")
Printer.ShowPrintDialog(reportData)

The code examples page shows additional format-specific scenarios. For PDF-specific workflows — generating a PDF and printing it immediately — IronPDF pairs naturally with IronPrint. The IronPrint vs. IronPDF comparison explains when to use each.

Next Steps

Printing with a dialog comes down to two methods: Printer.ShowPrintDialog() for synchronous calls and Printer.ShowPrintDialogAsync() for non-blocking execution. Pre-configure defaults with PrintSettings and let the user adjust from there. Both methods support all of IronPrint's document formats and work across WinForms, WPF, MAUI, and console projects.

Explore the IronPrint tutorials for full walkthroughs, the Printer class API reference for every available method, or the print settings how-to for advanced configuration. The changelog tracks recent improvements and new features.

Start a free 30-day trial to test dialog printing in a live project — no credit card required. When ready to ship, view licensing options starting at $749.