Android studio运行时闪退，请问怎么解决？

Question

java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.admin.study/com.example.admin.study.NoteActivity}: java.lang.ClassCastException: android.support.design.widget.FloatingActionButton cannot be cast to android.widget.Button
                      at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:4060)
                      at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:4247)
                      at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:91)
                      at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:149)
                      at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:103)
                      at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2613)
                      at android.os.Handler.dispatchMessage(Handler.java:110)
                      at android.os.Looper.loop(Looper.java:219)
                      at android.app.ActivityThread.main(ActivityThread.java:8668)
                      at java.lang.reflect.Method.invoke(Native Method)
                      at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:513)
                      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1109)
                   Caused by: java.lang.ClassCastException: android.support.design.widget.FloatingActionButton cannot be cast to android.widget.Button
                      at com.example.admin.study.NoteActivity.init(NoteActivity.java:45)
                      at com.example.admin.study.NoteActivity.onCreate(NoteActivity.java:39)
                      at android.app.Activity.performCreate(Activity.java:8214)
                      at android.app.Activity.performCreate(Activity.java:8202)
                      at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1320)
                      at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:4033)
                      at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:4247) 
                      at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:91) 
                      at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:149) 
                      at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:103) 
                      at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2613) 
                      at android.os.Handler.dispatchMessage(Handler.java:110) 
                      at android.os.Looper.loop(Looper.java:219) 
                      at android.app.ActivityThread.main(ActivityThread.java:8668) 
                      at java.lang.reflect.Method.invoke(Native Method) 
                      at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:513) 
                      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1109)

Answer 1

报错信息很清楚了：

FloatingActionButton类不能转换为Button