实例化SersonMessage时报错

Question

//        mSensorManager = (SensorManager) context.getSystemService(Context.SENSOR_SERVICE);-------------->                                                               java.lang.RuntimeException: Unable to start activity ComponentInfo{com.Cal.bdmap/com.Cal.bdmap.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.Object android.content.Context.getSystemService(java.lang.String)' on a null object reference

Answer 1

context没有赋值吧