:trying to do something in a way that will not be successful找错了目标；走错了方向；白费力气
If you are looking for money, you're barking up the wrong tree. [=you are asking the wrong person]如果你是为了要钱，那你找错人了。
She claims that researchers are barking up the wrong tree by focusing on conventional forms of treatment for the disease.她声称，研究人员将注意力集中在这种病的常规疗法上是犯了方向性错误。