copy tick 函数经常无法取到tick;function “copy tick”sometimes cannot get tick

overgrown  

CopyTicks(NULL,tickay,COPY_TICKS_TRADE,1,50);

这个函数经常无法取到tick,请问用法上有什么要注意的吗?成因可能是什么?

this function sometimes cannot get ticks, are there anything wrong with my usage? What might be the cause?

Blur Darkness  

应该要先定义symbol,我一般选择COPY_TICKS_INFO,数据信息更多。如

CopyTicks("XAUUSD",tick_array,COPY_TICKS_INFO,0,ticks);

原因: