PrintDialog printDialog = new PrintDialog();

printDialog.Document = printDocument1;

try

{

    printDialog.Document.DefaultPageSettings.Landscape = false;//纵向打印

    printDocument1.Print();

}

catch

{

    printDocument1.PrintController.OnEndPrint(printDocument1, new System.Drawing.Printing.PrintEventArgs());//停止打印

}



private void printDocument1_PrintPage(object sender, System.Drawing.Printing.PrintPageEventArgs e)

{

	//打印内容

    e.Graphics.DrawImage(pictureBox3.Image, 0, 0, pictureBox3.Image.Width, pictureBox3.Image.Height);

}

首先引用：
System.Printing
System.windows.forms;
System.drawing;

 /// <summary>
        /// 打印对象
        /// </summary>
        private System.Windows.Controls.PrintDialog printDialog;
        /// <summary>
        /// 打印机对象
        /// </summary>
        private PrintQueue printer;

构造函数或者其它方法中：
           // 打印机    
            printDialog = new System.Windows.Controls.PrintDialog();
            // 选择打印机
            printer = new LocalPrintServer().GetPrintQueue("你的打印机名称“);

调用方法中：
            if (printDialog != null)
                {
                    if (printer != null)
                    {
                        // 设置当前打印机
                        printDialog.PrintQueue = printer;
                        var txtblock = new TextBlock();
                        txtblock.Text = "hello";
                        printDialog.PrintVisual(txtblock, "测试");
                    }
                    else
                    {
                        MessageBox.Show("请先安装小票打印机");
                    }
                }

谢谢上面的回复，目前只是想调用打印机打印空白A4纸，有没有简洁的方法。