//【2】在工具里面找打印printDocument1工具，在事件里 PrintPage表示（对于要打印的每一页发生一次）
private void printDocument1_PrintPage(object sender, System.Drawing.Printing.PrintPageEventArgs e)
{
//【2.1】创建USBPrint
//【2.2】调用USBPrint里面的Print方法
//【2.3】productList, txtSerialNum.Text.Trim(), toollblName.Text.Trim()都是要打印的内容
USBPrint.Print(e, productList, txtSerialNum.Text.Trim(), toollblName.Text.Trim());
}
private void printDocument_PrintPage(object sender, System.Drawing.Printing.PrintPageEventArgs e)
{
USBPrint.Print(e, productList, txtSerialNum.Text.Trim(), toollblName.Text.Trim());
}
private void printDocument1_PrintPage(object sender, System.Drawing.Printing.PrintPageEventArgs e)
{
USBPrint.Print(e, productList, txtSerialNum.Text.Trim(), toolStripStatusLabel5.Text.Trim());
}