java - oncreate Application 类中的 IllegalStateException

Question

我收到错误 java.lang.RuntimeException Caused by: java.lang.IllegalStateException in super.onCreate() in android version 8.0

public final class ClockApp extends Application {
 @Override
 public void onCreate() {
     super.onCreate();
     startService(new Intent(getApplicationContext(), MyService.class));
  }
}

错误日志如下:

java.lang.RuntimeException: 
  at android.app.ActivityThread.handleBindApplication (ActivityThread.java:6065)
  at android.app.ActivityThread.-wrap1 (Unknown Source)
  at android.app.ActivityThread$H.handleMessage (ActivityThread.java:1764)
  at android.os.Handler.dispatchMessage (Handler.java:105)
  at android.os.Looper.loop (Looper.java:164)
  at android.app.ActivityThread.main (ActivityThread.java:6942)
  at java.lang.reflect.Method.invoke (Method.java)
  at com.android.internal.os.Zygote$MethodAndArgsCaller.run (Zygote.java:327) 
  at com.android.internal.os.ZygoteInit.main (ZygoteInit.java:1374)

Caused by: java.lang.IllegalStateException: 
  at android.app.ContextImpl.startServiceCommon (ContextImpl.java:1538)
  at android.app.ContextImpl.startService (ContextImpl.java:1484)
  at android.content.ContextWrapper.startService (ContextWrapper.java:663)
  at com.alarm.speakingclock.ClockApp.onCreate (ClockApp.java:14)
  at android.app.Instrumentation.callApplicationOnCreate (Instrumentation.java:1126)
  at android.app.ActivityThread.handleBindApplication (ActivityThread.java:6062)
  at android.app.ActivityThread.-wrap1 (Unknown Source)
  at android.app.ActivityThread$H.handleMessage (ActivityThread.java:1764)
  at android.os.Handler.dispatchMessage (Handler.java:105)
  at android.os.Looper.loop (Looper.java:164)
  at android.app.ActivityThread.main (ActivityThread.java:6942)
  at java.lang.reflect.Method.invoke (Method.java) 
  at com.android.internal.os.Zygote$MethodAndArgsCaller.run (Zygote.java:327)
  at com.android.internal.os.ZygoteInit.main (ZygoteInit.java:1374)

Answer 1

从 API 26 开始，当应用不在前台时，以及在 Application.onCreate() 调用期间，您无法启动服务它仍然不在前台 。

引用:https://developer.android.com/guide/components/services#StartingAService

因此有一些可能的方法来解决这个问题:

• (很好的解决方案)延迟服务启动，直到应用程序进入前台。例如 - 启动器 Activity 的 onCreate 方法。
• (好的解决方案)使用startForegroundService()
• (不确定是否有效，糟糕的解决方案)将 targetSDK 降级到 26 以下