Android学习第九天

动态注册监听时间变化

class MainActivity : AppCompatActivity() {
lateinit var timeChangeReceiver: TimeChangeReceiver
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
val intentFilter = IntentFilter()
intentFilter.addAction("android.intent.action.TIME_TICK")
timeChangeReceiver = TimeChangeReceiver()
registerReceiver(timeChangeReceiver, intentFilter)
}
override fun onDestroy() {
super.onDestroy()
unregisterReceiver(timeChangeReceiver)
}
inner class TimeChangeReceiver : BroadcastReceiver() {
override fun onReceive(context: Context, intent: Intent) {
Toast.makeText(context, "Time has changed", Toast.LENGTH_SHORT).show()
}
}
}

静态注册的代码示例如下:

class BootCompleteReceiver : BroadcastReceiver() {
override fun onReceive(context: Context, intent: Intent) {
Toast.makeText(context, "Boot Complete", Toast.LENGTH_LONG).show()
}
}

 另外,静态的BroadcastReceiver一定要在AndroidManifest.xml文件中注册才可以使用:

manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.broadcasttest">
<uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:roundIcon="@mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="@style/AppTheme">

<receiver
android:name=".BootCompleteReceiver"
android:enabled="true"
android:exported="true">
<intent-filter>
<action android:name="android.intent.action.BOOT_COMPLETED" />
</intent-filter>
</receiver>
</application>
</manifest>

 

原文地址:https://www.cnblogs.com/yongyuandishen/p/14867331.html