CRASH问题:java.lang.NullPointerException

java.lang.NullPointerException: Attempt to invoke virtual method ‘void android.widget.ImageView.setImageResource(int)’ on a null object reference 今天在家练习ListView的时候,遇到一个java.lang.NullPointerException的空指针异常,log如下: 2020-05-10 15:40:29.249 20436-20436/? E/k.myapplicatio: Unknown bits set in runtime_flag