经典的ADX交叉（+，- DI线），作者用于M15，也可考虑用于其它周期

若用作信号，一般需要叠加其它指标

double b4plusdi,b4minusdi,nowplusdi,nowminusdi;
int start()
  {
   b4plusdi=iADX(NULL,0,14,PRICE_CLOSE,MODE_PLUSDI,1);
   nowplusdi=iADX(NULL,0,14,PRICE_CLOSE,MODE_PLUSDI,0);
   
   b4minusdi=iADX(NULL,0,14,PRICE_CLOSE,MODE_MINUSDI,1);
   nowminusdi=iADX(NULL,0,14,PRICE_CLOSE,MODE_MINUSDI,0);
    
   if(b4plusdi>b4minusdi &&
         nowplusdi<nowminusdi)
      {
      Alert(Symbol()," ",Period()," ADX SELLING");
      }   
      if(b4plusdi<b4minusdi &&
         nowplusdi>nowminusdi)
       {
         Alert(Symbol()," ",Period()," ADX BUYING");
        }
      }
   return(0);
  // }