How to programmatically print to PDF file without prompting for filename in C# using the Microsoft Print To PDF printer that comes with Windows 10

Microsoft Windows 10 comes with a Microsoft Print To PDF printer which can print something to a PDF file. It prompts for the filename to download.

How can I programmatically control this from C# to not prompt for the PDF filename but save to a specific filename in some folder that I provide?

This is for batch processing of printing a lot of documents or other types of files to a PDF programmatically.

To print a PrintDocument object using the Microsoft Print to PDF printer without prompting for a filename, here is the pure code way to do this:

// generate a file name as the current date/time in unix timestamp format
string file = (DateTime.UtcNow.Subtract(new DateTime(1970, 1, 1))).TotalSeconds.ToString();

// the directory to store the output.
string directory = Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments);

// initialize PrintDocument object
PrintDocument doc = new PrintDocument() {
	PrinterSettings = new PrinterSettings() {
		// set the printer to 'Microsoft Print to PDF'
		PrinterName = "Microsoft Print to PDF",
		
		// tell the object this document will print to file
		PrintToFile = true,
		
		// set the filename to whatever you like (full path)
		PrintFileName = Path.Combine(directory, file + ".pdf"),
	}
};

doc.Print();

You can also use this method for other Save as File type printers such as Microsoft XPS Printer

You can print to the Windows 10 PDF printer, by using the PrintOut method and specifying the fourth output file name parameter, as in the following example:

/// <summary>
/// Convert a file to PDF using office _Document object
/// </summary>
/// <param name="InputFile">Full path and filename with extension of the file you want to convert from</param>
/// <returns></returns>
public void PrintFile(string InputFile)
{
	// convert input filename to new pdf name
    object OutputFileName = Path.Combine(
	    Path.GetDirectoryName(InputFile),
	    Path.GetFileNameWithoutExtension(InputFile)+".pdf"
    );


	// Set an object so there is less typing for values not needed
	object missing = System.Reflection.Missing.Value;

	// `doc` is of type `_Document`
	doc.PrintOut(
		ref missing,	// Background
		ref missing,	// Append
		ref missing,	// Range
		OutputFileName,	// OutputFileName
		ref missing,	// From
		ref missing,	// To
		ref missing,	// Item
		ref missing,	// Copies
		ref missing,	// Pages
		ref missing,	// PageType
		ref missing,	// PrintToFile
		ref missing,	// Collate
		ref missing,	// ActivePrinterMacGX
		ref missing,	// ManualDuplexPrint
		ref missing,	// PrintZoomColumn
		ref missing,	// PrintZoomRow
		ref missing,	// PrintZoomPaperWidth
		ref missing,	// PrintZoomPaperHeight
	);
}

The OutputFile is a full path string of the input document you would like to convert, and the doc is a regular document object. For more info about the doc please see the following MSDN links for _Document.PrintOut()

• Office 2003
• Office 2013 and later

The PrintOut in the example results a silent print, when you print through the specified inputFile to the OutputFileName, which will be placed in the same folder as the original document, but it will be in PDF format with the .pdf extension.