Beginning with Android 8.0 (API level 26), the system imposes additional restrictions on manifest-declared receivers.
If your app targets Android 8.0 or higher, you cannot use the manifest to declare a receiver for most implicit broadcasts (broadcasts that don't target your app specifically). You can still use a context-registered receiver when the user is actively using your app.
Android为了防止静态注册的广播耗费资源,禁用了一些在Manifest文件中注册的广播。导致收不到消息,在logcat中能看到类似这样的日志
2019-10-08 00:02:29.523 350-365/system_process W/BroadcastQueue: Background execution not allowed: receiving Intent { act=android.intent.action.BATTERY_LOW flg=0x4000010 (has extras) } to com.hncj.android/.PowerStateReceiver
说明广播被系统拦截了.
这里是仍然可以使用静态注册的系统广播:
https://developer.android.google.cn/guide/components/broadcast-exceptions?hl=en
解决方法:
1、想要接收系统广播,似乎只有降低targetSdkVersion为25或以下,但此种方式Manifest文件会报错,需要在前面加一句:
//noinspection ExpiredTargetSdkVersion
targetSdkVersion 25
降低targetSdkVersion后,项目也会编译报错,找不到一些类,资源、样式等文件。需要删除build.gradle中的:
implementation 'androidx.appcompat:appcompat:1.1.0'
implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
同时activity类不要继承AppCompatActivity,直接继承Activity.酌情删除或修改Manifest.xml中的theme、roundIcon等样式,酌情删除一些图片,变量定义文件。
2、对于自定义的广播,想要使用静态注册,网上也提供了解决方案:
如:在sendBroadcast方法之前,调用intent的setPackage或setComponent方法,为其设置具体的接收者;
或者使用intent的addFlag方法,阻止系统拦截广播
intent.addFlags(0x01000000);
详细可参考: https://www.jianshu.com/p/5283ebc225d5?utm_source=oschina-app