你试试这样效果可以吗?
for(int i=0; i<limit; i++)
{
double B,a1,a2;
a1 = Close- iBands(NULL,0,BandPeriod,Deviation,0,PRICE_CLOSE,MODE_LOWER,i) ;
a2 = iBands(NULL,0,BandPeriod,Deviation,0,PRICE_CLOSE,MODE_UPPER,i) - iBands(NULL,0,BandPeriod,Deviation,0,PRICE_CLOSE,MODE_LOWER,i);
B = a1/a2;
ExtMapBuffer1= B ;
if(ExtMapBuffer1[i+1] > 0 && ExtMapBuffer1 < 0 && i==0)Alert("小于0提示:",Symbol()," 时段:",Period(),"分钟,值:",B);
if(ExtMapBuffer1[i+1] < 1.0 && ExtMapBuffer1 > 1.0 && i==0)Alert("大于1提示:",Symbol()," 时段:",Period(),"分钟,值:",B);
}