java.lang.RuntimeException:无法启动活动android.widget.Button.setOnClickListener(android.view.View$OnClickListener)‘java.lang.NullPointerException(Looper.java:135) at android.app.ActivityThread.main(ActivityThread.java:5254) at java.lang.reflect.Method.invoke(原生方法)在java.lang.refl
: Attempt to invokevirtualmethod 'void java.util.concurrent.atomic.AtomicReference.set(java.lang.ObjectLooper.java:156) at java.lang.reflect.Method.invoke)
a
: Attempt to invokevirtualmethod 'void android.support.design.widget.FloatingActionButton.setOnClickListener148) at java.lang.reflect.Method.invoke726)
to activity {com.example.ryans_000.facebooklogin/com.example.ryans_000.facebooklogin.MainActivity}: java.lang.NullPointerException: Attempt to invokevirtualmethod 'java.lang.String java.lang.Throwable.toString()' on a null object34:45.306