设置默认的打印机及打印纸，在打印机中设置纸张类型。这样就可以精确的设置打印纸的尺寸，这在针式打印机中连续走纸的情况下可以准确地设置打纸张的尺寸。 -Set the default printer and printing paper, paper type in the printer settings. This allows accurate printing paper size settings, which come and go in the dot matrix printer

Change Desire Printer as Default Printer in runtime and Restore old printer to restore as default