((AppCompatActivity) getActivity()).setSupportActionBar(toolbar)报错

Process: com.nsisoft.charmcampus.charmcampus, PID: 2835

java.lang.RuntimeException: Unable to start activity ComponentInfo{com.nsisoft.charmcampus.charmcampus/com.nsisoft.charmcampus.charmcampus.MainActivity}: java.lang.ClassCastException: com.nsisoft.charmcampus.charmcampus.MainActivity cannot be cast to android.support.v7.app.AppCompatActivity

at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2646)

at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2707)

at android.app.ActivityThread.-wrap12(ActivityThread.java)

at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1460)

at android.os.Handler.dispatchMessage(Handler.java:102)

at android.os.Looper.loop(Looper.java:154)

at android.app.ActivityThread.main(ActivityThread.java:6077)

at java.lang.reflect.Method.invoke(Native Method)

at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:865)

at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755)

Caused by: java.lang.ClassCastException: com.nsisoft.charmcampus.charmcampus.MainActivity cannot be cast to android.support.v7.app.AppCompatActivity

at com.nsisoft.charmcampus.charmcampus.Auditorium.onCreateView(Auditorium.java:73)

at android.support.v4.app.Fragment.performCreateView(Fragment.java:2080)

at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1108)

at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1290)

at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:801)

at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1677)

at android.support.v4.app.FragmentController.execPendingActions(FragmentController.java:388)

at android.support.v4.app.FragmentActivity.onStart(FragmentActivity.java:604)

at android.app.Instrumentation.callActivityOnStart(Instrumentation.java:1248)

at android.app.Activity.performStart(Activity.java:6681)

at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2609)