onCreate从Java转换到Kotlin后崩溃

Question

我将我的Launcher Activity从Java转换为Kotlin，并且在onCreate（）中发生崩溃，我不明白它为什么会崩溃。

的Java：

@Override 
protected void onCreate(Bundle savedInstanceState) { 
super.onCreate(savedInstanceState); 

科特林：

override fun onCreate(savedInstanceState: Bundle?) { 
super.onCreate(savedInstanceState) 

调用堆栈：

java.lang.RuntimeException: Unable to start activity ComponentInfo{com.a.b.c/com.a.b.c.Authentication.AuthenticationActivity}: java.lang.IllegalArgumentException: Parameter specified as non-null is null: method kotlin.jvm.internal.Intrinsics.checkParameterIsNotNull, parameter savedInstanceState 
                     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2416) 
                     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476) 
                     at android.app.ActivityThread.-wrap11(ActivityThread.java) 
                     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344) 
                     at android.os.Handler.dispatchMessage(Handler.java:102) 
                     at android.os.Looper.loop(Looper.java:148) 
                     at android.app.ActivityThread.main(ActivityThread.java:5417) 
                     at java.lang.reflect.Method.invoke(Native Method) 
                     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726) 
                     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616) 
                    Caused by: java.lang.IllegalArgumentException: Parameter specified as non-null is null: method kotlin.jvm.internal.Intrinsics.checkParameterIsNotNull, parameter savedInstanceState 
                     at com.a.b.c.Activity.AppLifecycleTracker.onActivityCreated(AppLifecycleTracker.kt) 
                     at android.app.Application.dispatchActivityCreated(Application.java:195) 
                     at android.app.Activity.onCreate(Activity.java:922) 
                     at android.support.v4.app.FragmentActivity.onCreate(FragmentActivity.java:277) 
                     at android.support.v7.app.AppCompatActivity.onCreate(AppCompatActivity.java:85) 
                     at com.a.b.c.Authentication.AuthenticationActivity.onCreate(AuthenticationActivity.kt:147) 
                     at android.app.Activity.performCreate(Activity.java:6251) 
                     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1107) 
                     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2369) 
                     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476)  
                     at android.app.ActivityThread.-wrap11(ActivityThread.java)  
                     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)  
                     at android.os.Handler.dispatchMessage(Handler.java:102)  
                     at android.os.Looper.loop(Looper.java:148)  
                     at android.app.ActivityThread.main(ActivityThread.java:5417)  
                     at java.lang.reflect.Method.invoke(Native Method)  
                     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)  
                     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)  

Answer 1

貌似方法onActivityCreated在AppLifecycleTracker有一个参数savedInstanceState: Bundle，这应该是savedInstanceState: Bundle?，因为不一定有保存的状态可用在活动创建上，这意味着参数值可以是null。 Kotlin检查确认null safety。

崩溃似乎与活动本身的转换无关。