电话状态说明

打电话和来电话时处理 媒体音量的问题。现将逻辑说明如下：

1.来电话

监听类 PhoneStateListener

第一种状态：响铃：TelephonyManager.CALL_STATE_RINGING

第二种状态：接起电话： TelephonyManager.CALL_STATE_OFFHOOK

第三种状态：挂电话：TelephonyManager.CALL_STATE_IDLE

private PhoneStateListener mPhoneStateListener = new PhoneStateListener() {
@Override
public void onCallStateChanged(int state, String incomingNumber) {
if(DBG) Log.v(TAG,"onCallStateChanged()");
AudioManager audioManager = (AudioManager) getSystemService(Context.AUDIO_SERVICE);
// 当有电话进来时
if (state == TelephonyManager.CALL_STATE_RINGING) {
mbPhoneCall = true;
curVolume = audioManager.getStreamVolume(AudioManager.STREAM_MUSIC);// 获取当前音量值
audioManager.setStreamVolume(AudioManager.STREAM_MUSIC, 0, 0);//设置当前音量值为0
} else if (state == TelephonyManager.CALL_STATE_OFFHOOK) {
// 当有电话在等时
if(!mbPhoneCall) {
mbPhoneCall = true;
curVolume = audioManager.getStreamVolume(AudioManager.STREAM_MUSIC);// 获取当前音量值
audioManager.setStreamVolume(AudioManager.STREAM_MUSIC, 0, 0);//设置当前音量值为0
}
} else if (state == TelephonyManager.CALL_STATE_IDLE) {
// 当挂断电话时
if(mbPhoneCall) {
mbPhoneCall = false;
audioManager.setStreamVolume(AudioManager.STREAM_MUSIC, curVolume, 0); //还原音量值
}
}
}

};

2 打电话

HTC的手机开发过程中，在打电话的时候，没有发送该广播，只触发了类。状态为 TelephonyManager.CALL_STATE_OFFHOOK

第一种状态：打电话 监听类会触发 state = TelephonyManager.CALL_STATE_OFFHOOK，但是广播不一定能收到，HTC的手机就不会。

第二种状态：对方接通电话，state = TelephonyManager.CALL_STATE_OFFHOOK

第三种状态：挂电话，state = TelephonyManager.CALL_STATE_IDLE

// 添加类
IntentFilter filterOutCall = new IntentFilter();
filterOutCall.addAction(Intent.ACTION_NEW_OUTGOING_CALL);
registerReceiver(mPhoneOutCallListener, filterOutCall);

广播接收 private BroadcastReceiver mPhoneOutCallListener = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
AudioManager audioManager = (AudioManager) getSystemService(Context.AUDIO_SERVICE);
curVolume = audioManager.getStreamVolume(AudioManager.STREAM_MUSIC);
mbPhoneCall = true;
}
};

将这些记录下来，总要是说明：打电话的接收广播，在一些手机中，是接收不到的，比如HTC的，所以打电话的处理逻辑必须在类中state == TelephonyManager.CALL_STATE_OFFHOOK进行处理。

权限： <uses-permission android:name="android.permission.READ_PHONE_STATE" /> 类的权限
<uses-permission android:name="android.permission.PROCESS_OUTGOING_CALLS" /> 打电话的监听权限