How can I send docx and pdf file to printer?

Question

I have the following code which prints text file from C# to printer its based on the this article it prints plain text perfect but when I try to print .docx and .pdf file it prints but convert the content to some-kind of encoded characters. How can I fix this to print pdf and doc file?

private void btnPrint_Click(object sender, EventArgs e)
{
    // Select the desired printer. ps.Duplex = Duplex.Simplex; // This works
    pdocFile.PrinterSettings.PrinterName = cboPrinter.Text;
    pdocFile.PrinterSettings.Duplex =  Duplex.Horizontal;
    // Print the checked files.
    foreach (string filename in clbFiles.CheckedItems)
    {
        Console.WriteLine("Printing: " + filename);

        // Get the file's name without the path.
        FileInfo file_into = new FileInfo(filename);
        string short_name = file_into.Name;

        // Set the PrintDocument's name for use by the printer queue.
        pdocFile.DocumentName = short_name;

        // Read the file's contents.
        try
        {
            FileContents = File.ReadAllText(filename).Trim();
        }
        catch (Exception ex)
        {
            MessageBox.Show("Error reading file " + filename +
                    ".\n" + ex.Message);
            return;
        }

        // Print.
        pdocFile.Print();
    }

    MessageBox.Show("Spooled " + clbFiles.CheckedItems.Count +
            " files for printing.");
    }

//

private string FileContents;

// Print a page of the text file.
private void pdocTextFile_PrintPage(object sender, PrintPageEventArgs e)
{
    // Make a font for printing.
    using (Font font = new Font("Courier New", 10))
    {
        // Make a StringFormat to align text normally.
        using (StringFormat string_format = new StringFormat())
        {
            // See how much of the remaining text will fit.
            SizeF layout_area = new SizeF(e.MarginBounds.Width, e.MarginBounds.Height);
            int chars_fitted, lines_filled;
            e.Graphics.MeasureString(FileContents, font,
            layout_area, string_format,
            out chars_fitted, out lines_filled);

            // Print as much as will fit.
            e.Graphics.DrawString(
            FileContents.Substring(0, chars_fitted),
            font, Brushes.Black, e.MarginBounds,
            string_format);

            // Remove the printed text from the string.
            FileContents = FileContents.Substring(chars_fitted).Trim();
        }
    }

    // See if we are done.
    e.HasMorePages = FileContents.Length > 0;
}

see Image link below

Answer 1

Your example above is taking a binary file format and trying to print it using a method that uses plain text, which will not work. You have a few options on how you could approach this.

1. Some printers allow you to submit various file types directly to them over a protocol like FTP. And example of this can be seen here. This method works great in enterprise environments which have business printers but is limited to the file types supported by each printer, and each printer's unique requirements.
2. For some formats, you can use third-party libraries like iText in your C# code to handle the actual printing. This option gives you a ton of control over the formatting, with the overhead of having to maintain additional code for every file type you wish to support.
3. You can also use the example code posted here to utilize already installed applications. In this example, it takes advantage of the Print verb made available by Adobe Acrobat, Word, etc. You'll need to make sure the applications have their defaults and surface the correct verb (which typically correlates with the context menu when right-clicking on a file name). This method is probably the most straight-forward option to handle files as-is.