发送标准广播

新建一个MyBroadcastReceiver，并加入接收的广播的代码，不然发送了不接收我们也不知道

class BootCompleteReceiver : BroadcastReceiver() {

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

        <receiver
            android:name=".MyBroadcastReceiver"
            android:enabled="true"
            android:exported="true">
            <intent-filter>
                <action android:name="com.example.broadcasttest.MY_BROADCAST" />
            </intent-filter>
        </receiver>

接下来，就为发送广播做准备了
修改activity_main.xml中的代码

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <Button
        android:id="@+id/button"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Send Broadcast" />

</LinearLayout>

这个按钮用来作为发送广播的触发点
然后再MainActivity中加入的代码：

        val button: Button = findViewById(R.id.button);
        button.setOnClickListener {
            val intent = Intent("com.example.broadcasttest.MY_BROADCAST")
            intent.setPackage(packageName)
            sendBroadcast(intent)
        }

这样运行点击按钮就会发送广播，被所有监听com.example.broadcasttest.MY_BROADCAST的BR接收到

发送有序广播

新建AnotherBroadcastReceiver，添加Toast和与前一个Receiver一样的配置信息

Toast.makeText(context, "received in AnotherMyBroadcastReceiver", Toast.LENGTH_SHORT).show()

            <intent-filter>
                <action android:name="com.example.broadcasttest.MY_BROADCAST" />
            </intent-filter>

再在MainActivity中将发送广播的方法从sendBroadcast()改成sendOrderedBroadcast()，第二个参数是一个与权限相关的字符串，这里传入null就可以了。

sendOrderedBroadcast(intent, null)

此时运行还不能体现有序广播的同步执行策略，我们需要给BR设定优先级
在AndroidManifest.xml中给前一个BR设定优先级为100

        <receiver
            android:name=".MyBroadcastReceiver"
            android:enabled="true"
            android:exported="true">
            <intent-filter android:priority="100">
                <action android:name="com.example.broadcasttest.MY_BROADCAST" />
            </intent-filter>
        </receiver>

然后在前一个BR的逻辑中尝试阻断广播

class MyBroadcastReceiver : BroadcastReceiver() {

    override fun onReceive(context: Context, intent: Intent) {
        Toast.makeText(context, "received in MyBroadcastReceiver", Toast.LENGTH_SHORT).show()
        abortBroadcast()
    }
}