萌新用android studio写了个程序但运行时一直显示“××停止运行”，求大佬们帮忙看看

qq_45025517 2019-05-06 10:51:39

2019-05-06 22:46:09.205 5105-5105/? I/e.my_metal_slu: Not late-enabling -Xcheck:jni (already on) 2019-05-06 22:46:09.308 5105-5105/? W/e.my_metal_slu: Unexpected CPU variant for X86 using defaults: x86 2019-05-06 22:46:09.882 5105-5105/com.example.my_metal_slug W/e.my_metal_slu: JIT profile information will not be recorded: profile file does not exits. 2019-05-06 22:46:09.886 5105-5105/com.example.my_metal_slug I/chatty: uid=10085(com.example.my_metal_slug) identical 10 lines 2019-05-06 22:46:09.886 5105-5105/com.example.my_metal_slug W/e.my_metal_slu: JIT profile information will not be recorded: profile file does not exits. 2019-05-06 22:46:09.920 5105-5105/com.example.my_metal_slug I/InstantRun: starting instant run server: is main process 2019-05-06 22:46:10.071 5105-5105/com.example.my_metal_slug D/AndroidRuntime: Shutting down VM 2019-05-06 22:46:10.073 5105-5105/com.example.my_metal_slug E/AndroidRuntime: FATAL EXCEPTION: main Process: com.example.my_metal_slug, PID: 5105 java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.my_metal_slug/com.example.my_metal_slug.MainActivity}: java.lang.ClassCastException: android.support.constraint.ConstraintLayout cannot be cast to android.widget.FrameLayout at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2913) at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3048) at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:78) at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:108) at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:68) at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1808) at android.os.Handler.dispatchMessage(Handler.java:106) at android.os.Looper.loop(Looper.java:193) at android.app.ActivityThread.main(ActivityThread.java:6669) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858) Caused by: java.lang.ClassCastException: android.support.constraint.ConstraintLayout cannot be cast to android.widget.FrameLayout at com.example.my_metal_slug.MainActivity.onCreate(MainActivity.java:50) at android.app.Activity.performCreate(Activity.java:7136) at android.app.Activity.performCreate(Activity.java:7127) at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1271) at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2893) at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3048) at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:78) at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:108) at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:68) at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1808) at android.os.Handler.dispatchMessage(Handler.java:106) at android.os.Looper.loop(Looper.java:193) at android.app.ActivityThread.main(ActivityThread.java:6669) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)

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