Android 为什么只调用超级实现的方法重写会使我的应用程序崩溃
为了在一个简单的Android 为什么只调用超级实现的方法重写会使我的应用程序崩溃,android,android-support-library,Android,Android Support Library,为了在一个简单的Android.support.v7.app.AppCompatActivity#AppCompatActivity中理解Android的生命周期,我重写了许多“on”方法来记录它们的执行情况 我补充说: // This override will crash app! override fun onCreateView(name: String?, context: Context?, attrs: AttributeSet?): View { //log {"onCr
Android.support.v7.app.AppCompatActivity#AppCompatActivity
中理解Android的生命周期,我重写了许多“on”方法来记录它们的执行情况
我补充说:
// This override will crash app!
override fun onCreateView(name: String?, context: Context?, attrs: AttributeSet?): View {
//log {"onCreateView(3)"}
return super.onCreateView(name, context, attrs)
}
结果是应用程序现在崩溃,原因是:
06-18 06:56:54.627 1004-1004/com.hanafey.prefone E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.hanafey.prefone, PID: 1004
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.hanafey.prefone/com.hanafey.prefone.MainActivity}: android.view.InflateException: Binary XML file line #24: Error inflating class LinearLayout
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2325)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2387)
at android.app.ActivityThread.access$800(ActivityThread.java:151)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1303)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5254)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)
Caused by: android.view.InflateException: Binary XML file line #24: Error inflating class LinearLayout
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:763)
at android.view.LayoutInflater.inflate(LayoutInflater.java:482)
at android.view.LayoutInflater.inflate(LayoutInflater.java:414)
at android.view.LayoutInflater.inflate(LayoutInflater.java:365)
at com.android.internal.policy.impl.PhoneWindow.generateLayout(PhoneWindow.java:3605)
at com.android.internal.policy.impl.PhoneWindow.installDecor(PhoneWindow.java:3677)
at com.android.internal.policy.impl.PhoneWindow.getDecorView(PhoneWindow.java:1943)
at android.support.v7.app.AppCompatDelegateImplV9.createSubDecor(AppCompatDelegateImplV9.java:374)
at android.support.v7.app.AppCompatDelegateImplV9.ensureSubDecor(AppCompatDelegateImplV9.java:323)
at android.support.v7.app.AppCompatDelegateImplV9.setContentView(AppCompatDelegateImplV9.java:284)
at android.support.v7.app.AppCompatActivity.setContentView(AppCompatActivity.java:139)
at com.hanafey.prefone.MainActivity.onCreate(MainActivity.kt:165)
at android.app.Activity.performCreate(Activity.java:5990)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1106)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2278)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2387)
at android.app.ActivityThread.access$800(ActivityThread.java:151)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1303)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5254)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)
Caused by: java.lang.IllegalStateException: super.onCreateView(name, context, attrs) must not be null
at com.hanafey.prefone.MainActivity.onCreateView(MainActivity.kt:59)
at android.app.Activity.onCreateView(Activity.java:5325)
at android.support.v4.app.BaseFragmentActivityApi14.onCreateView(BaseFragmentActivityApi14.java:41)
at android.support.v4.app.FragmentActivity.onCreateView(FragmentActivity.java:68)
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:733)
at android.view.LayoutInflater.inflate(LayoutInflater.java:482)
at android.view.LayoutInflater.inflate(LayoutInflater.java:414)
at android.view.LayoutInflater.inflate(LayoutInflater.java:365)
at com.android.internal.policy.impl.PhoneWindow.generateLayout(PhoneWindow.java:3605)
at com.android.internal.policy.impl.PhoneWindow.installDecor(PhoneWindow.java:3677)
at com.android.internal.policy.impl.PhoneWindow.getDecorView(PhoneWindow.java:1943)
at android.support.v7.app.AppCompatDelegateImplV9.createSubDecor(AppCompatDelegateImplV9.java:374)
at android.support.v7.app.AppCompatDelegateImplV9.ensureSubDecor(AppCompatDelegateImplV9.java:323)
at android.support.v7.app.AppCompatDelegateImplV9.setContentView(AppCompatDelegateImplV9.java:284)
at android.support.v7.app.AppCompatActivity.setContentView(AppCompatActivity.java:139)
at com.hanafey.prefone.MainActivity.onCreate(MainActivity.kt:165)
at android.app.Activity.performCreate(Activity.java:5990)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1106)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2278)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2387)
at android.app.ActivityThread.access$800(ActivityThread.java:151)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1303)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5254)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)
(甚至删除了log语句,使其成为纯非重写)
我会本能地说,这种覆盖只是一种禁止操作——无用但无害。
我猜这一定是由于黑客的包袱中的某些反射导致的,以支持旧平台,但了解真正的问题是很好的。问题是super可以返回null,但您的返回类型不能为null。如果您将其更改为以下内容,它将起作用:
override fun onCreateView(name: String?, context: Context?, attrs: AttributeSet?): View? {
//log {"onCreateView(3)"}
return super.onCreateView(name, context, attrs)
}
谢谢你的回答!IDE不应该指出没有可空返回时间的方法是对java方法的有效重写,它甚至可以建议修复。现在也很清楚,异常确实在运行时明确指出了错误的原因。