利用四个月的时间,从上层到hal层以上全部弄清楚,现在开始耳机插入事件的检测。
检测耳机的插拔事件,如果有耳机插入,弹出一个toast提示耳机已经插入,如果又耳机拔出,弹出一个toast提示耳机已经拔出。
新建一个工程命名为HeadsetConnection
新建一个类HeadsetPlugReceiver类用于接收耳机插入事件的广播。
代码如下所示
1. activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.audio.android.headsetconnection.MainActivity">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="HeadsetConnection APP"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</android.support.constraint.ConstraintLayout>
2. HeadsetPlugReceiver.java
package com.audio.android.headsetconnection;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.widget.Toast;
/**
* Created by wang on 17-6-15.
*/
public class HeadsetPlugReceiver extends BroadcastReceiver {
@Override
public void onReceive(Context context, Intent intent) {
if (intent.hasExtra("state")) {
if (intent.getIntExtra("state", 0) == 0) {
Toast.makeText(context, "headset not connected", Toast.LENGTH_LONG).show();
}
if (intent.getIntExtra("state", 0) == 1) {
Toast.makeText(context, "headset connected", Toast.LENGTH_LONG).show();
}
}
}
}
3. MainActivity.java
package com.audio.android.headsetconnection; import android.content.IntentFilter; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; public class MainActivity extends AppCompatActivity { private HeadsetPlugReceiver headsetPlugReceiver; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); registerHeadsetPlugReceiver(); } private void registerHeadsetPlugReceiver() { headsetPlugReceiver = new HeadsetPlugReceiver(); IntentFilter intentFilter = new IntentFilter(); intentFilter.addAction("android.intent.action.HEADSET_PLUG"); registerReceiver(headsetPlugReceiver, intentFilter); } @Override public void onDestroy() { unregisterReceiver(headsetPlugReceiver); super.onDestroy(); } }
手机界面:
这章中有个疑问广播是谁发送的呢?