_____________________________________________________________ 功能:同时按键抢答,先按的有效,其他按键锁死,复位后进行下一轮抢答 时间:2010—7—19 _____________________________________________________________ #include<reg52.h> sbit key1=P3^0; sbit key2=P3^1; sbit key3=P3^2; sbit key4=P3^3; main() { bit Flag; while(!Flag) { if(!key1) { P1=0xFE; Flag=1; } else if(!key2) { P1=0xFD; Flag=1; } else if(!key3) { P1=0xFB; Flag=1; } else if(!key4) { P1=0xF7; Flag=1; } } while(Flag); }