WINCE环境下，扫描头使用类，只需在程序开始时开启扫描头即可，在SYMBOL MC3000环境下测试成功，需要使用到SYMBOL的API库,PDA端程序-WINCE environment, scanning the first use of classes, just the beginning of the program can open the scan head, in SYMBOL MC3000 environment test is successful, need to use