Android xml布局文件中，

   android:foreground="?attr/selectableItemBackground"

	compileSdkVersion = 27minSdkVersion = 21targetSdkVersion = 27

2020-01-19 15:37:20.504 29770-29770/com.example.qixin E/AndroidRuntime: FATAL EXCEPTION: mainProcess: com.example.qixin, PID: 29770java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.qixin/com.example.qixin.app.fun.bbs.activity.VideoViewActivity}: android.view.InflateException: Binary XML file line #16 in com.example.qixin:layout/activity_video_view: Binary XML file line #16 in com.example.qixin:layout/activity_video_view: Error inflating class <unknown>at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3447)at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3594)at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:83)at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2146)at android.os.Handler.dispatchMessage(Handler.java:107)at android.os.Looper.loop(Looper.java:237)at android.app.ActivityThread.main(ActivityThread.java:7762)at java.lang.reflect.Method.invoke(Native Method)at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1047)Caused by: android.view.InflateException: Binary XML file line #16 in com.example.qixin:layout/activity_video_view: Binary XML file line #16 in com.example.qixin:layout/activity_video_view: Error inflating class <unknown>Caused by: android.view.InflateException: Binary XML file line #16 in com.example.qixin:layout/activity_video_view: Error inflating class <unknown>Caused by: java.lang.reflect.InvocationTargetExceptionat java.lang.reflect.Constructor.newInstance0(Native Method)at java.lang.reflect.Constructor.newInstance(Constructor.java:343)at android.view.LayoutInflater.createView(LayoutInflater.java:854)at android.view.LayoutInflater.createView(LayoutInflater.java:776)at com.android.internal.policy.PhoneLayoutInflater.onCreateView(PhoneLayoutInflater.java:58)at android.view.LayoutInflater.onCreateView(LayoutInflater.java:930)at android.view.LayoutInflater.onCreateView(LayoutInflater.java:950)at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:1004)at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:961)at android.view.LayoutInflater.rInflate(LayoutInflater.java:1123)at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:1084)at android.view.LayoutInflater.inflate(LayoutInflater.java:682)at android.view.LayoutInflater.inflate(LayoutInflater.java:534)at android.view.LayoutInflater.inflate(LayoutInflater.java:481)at com.android.internal.policy.PhoneWindow.setContentView(PhoneWindow.java:511)at android.app.Activity.setContentView(Activity.java:3408)at com.lepu.app.fun.bbs.activity.VideoViewActivity.onCreate(VideoViewActivity.java:31)at android.app.Activity.performCreate(Activity.java:7981)at android.app.Activity.performCreate(Activity.java:7970)at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1307)at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3422)at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3594)at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:83)at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2146)at android.os.Handler.dispatchMessage(Handler.java:107)at android.os.Looper.loop(Looper.java:237)at android.app.ActivityThread.main(ActivityThread.java:7762)at java.lang.reflect.Method.invoke(Native Method)at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1047)
2020-01-19 15:37:20.504 29770-29770/com.example.qixin E/AndroidRuntime: Caused by: java.lang.UnsupportedOperationException: Failed to resolve attribute at index 35: TypedValue{t=0x2/d=0x7f040147 a=-1}at android.content.res.TypedArray.getDrawableForDensity(TypedArray.java:996)at android.content.res.TypedArray.getDrawable(TypedArray.java:980)at android.view.View.<init>(View.java:6047)at android.widget.ImageView.<init>(ImageView.java:193)at android.widget.ImageView.<init>(ImageView.java:188)at android.widget.ImageView.<init>(ImageView.java:184)... 32 more

解决办法

把foreground属性去掉