VB应用程序中打印条形码的两种方法(国外英语资料).docVIP

VB应用程序中打印条形码的两种方法(国外英语资料) Two methods of printing barcodes in VB applications Release time: 2009-5-14 0:43:12 Double click the auto scroll screen [print this page] [close this page] As a kind of machine recognizable graphics, bar code can identify a product or commodity quickly and accurately. It plays an important role in many database applications, such as supermarket checkout, station ticket sales and so on. When an item with the bar code is the correct interpretation of barcode scanners, will be the only identifier string of the article, through searching the database we can know some of its other properties and the corresponding treatment. Although it can find many free and not free barcode printing controls in Internet, but in addition to the use of these controls is not convenient, and one of the biggest drawbacks: they cant print and our program is the presence of a printed page, for example in a process, we first to system Printer the output of some of the content, and then call the control bar code printing method, finally print two pages! If we want to process a ticket now, not only to print the bar code, but also to have terminal and fare information, then the control becomes unavailable. For programmers, perhaps still want to understand the principle of bar code printing, this paper proposes two printing methods One, directly use the printer that has the function of bar code printing There are many printers can directly print bar code, but in VB, we are familiar with the LPRINT statement in the DOS era has been unable to use, the printing operation has been completely taken over Spool Windows system, the output is page as a unit, print out all was converted to Windows driver to send print graphics. To make the printer to print the barcode must be sent directly to ESC sequences corresponding to it, so we have to think of ways to avoid the Windows Spool system, that is to say again in the program cannot use the Printer object and the Printers set process