//获取打印机列表
StringCollection strList = PrinterSettings.InstalledPrinters;

 PrintDocument pd = new PrintDocument();
pd.PrinterSettings.PrinterName = "Canon TS3100 series (副本 1)";

Font printFont = null;
StreamReader streamToPrint = null;
private void Button_Click_1(object sender, RoutedEventArgs e)
{
    try
    {
        streamToPrint = new StreamReader
            ("G:\\桌面\\新建文本文档.txt");
        try
        {
            printFont = new Font("Arial", 10);
            PrintDocument pd = new PrintDocument();
            pd.PrinterSettings.PrinterName = "Canon TS3100 series (副本 1)";
            pd.PrintPage += new PrintPageEventHandler
                (this.pd_PrintPage);
            pd.Print();
        }
        finally
        {
            streamToPrint.Close();
        }
    }
    catch (Exception ex)
    {
        MessageBox.Show(ex.Message);
    }
}
// The PrintPage event is raised for each page to be printed.
private void pd_PrintPage(object sender, PrintPageEventArgs ev)
{
    float linesPerPage = 0;
    float yPos = 0;
    int count = 0;
    float leftMargin = ev.MarginBounds.Left;
    float topMargin = ev.MarginBounds.Top;
    string line = null;

    // Calculate the number of lines per page.
    linesPerPage = ev.MarginBounds.Height /
        printFont.GetHeight(ev.Graphics);

    // Print each line of the file.
    while (count < linesPerPage &&
        ((line = streamToPrint.ReadLine()) != null))
    {
        yPos = topMargin + (count *
            printFont.GetHeight(ev.Graphics));
        ev.Graphics.DrawString(line, printFont, System.Drawing.Brushes.Black,
            leftMargin, yPos, new StringFormat());
        count++;
    }

    // If more lines exist, print another page.
    if (line != null)
        ev.HasMorePages = true;
    else
        ev.HasMorePages = false;
}