小编ary*_*raf的帖子

这是该应用程序的第二个活动。我已经在第一个活动中请求访问位置的权限。这是错误：

java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.livelocationfinder/com.example.livelocationfinder.MapsActivity}: java.lang.NullPointerException: Listener must not be null\n        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3123)\n        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3266)\n        at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:78)\n        at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:108)\n        at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:68)\n        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1957)\n        at android.os.Handler.dispatchMessage(Handler.java:106)\n        at android.os.Looper.loop(Looper.java:214)\n        at android.app.ActivityThread.main(ActivityThread.java:7099)\n        at java.lang.reflect.Method.invoke(Native Method)\n        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:494)\n        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:965)\n     Caused by: java.lang.NullPointerException: Listener must not be null\n        at com.google.android.gms.common.internal.Preconditions.checkNotNull(Unknown Source:11)\n        at com.google.android.gms.common.api.internal.ListenerHolders.createListenerHolder(Unknown Source:13)\n        at com.google.android.gms.location.FusedLocationProviderClient.requestLocationUpdates(Unknown Source:14)\n        at com.example.livelocationfinder.MapsActivity.onCreate(MapsActivity.java:54)\n        at android.app.Activity.performCreate(Activity.java:7327)\n        at android.app.Activity.performCreate(Activity.java:7318)\n        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1275)\n        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3103)\n        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3266)\xc2\xa0\n        at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:78)\xc2\xa0\n        at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:108)\xc2\xa0\n        at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:68)\xc2\xa0\n        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1957)\xc2\xa0\n        at android.os.Handler.dispatchMessage(Handler.java:106)\xc2\xa0\n        at android.os.Looper.loop(Looper.java:214)\xc2\xa0\n …