using System.Drawing.Printing;        //这是必备

for (int i = 0; i < PrinterSettings.InstalledPrinters.Count; i++)       //获取当前打印机
{
                comboBox1.Items.Add(PrinterSettings.InstalledPrinters[i])
}
            comboBox1.SelectedIndex = 0;

PrintDocument fPrintDocument = new PrintDocument();　　　　//获取默认打印机的方法

comboBox1.Text = fPrintDocument.PrinterSettings.PrinterName;