Android 聽筒模式的具體實現實例

2020-04-11 11:58:46

字體：大中小

來源：轉載

供稿：網友

一、利用距離感應器監聽聽筒靠近耳朵事件
準確的說距離感應器并不能監聽到你是否把手機靠近耳朵，也許是你用手擋在了距離感應器前面，但這不是我們關心的，我們關心的是當你的耳朵靠近聽筒時，我們要捕獲到這個事件

step 1，新建實現SensorEventListener接口的類并實現onSensorChanged(SensorEvent event)方法

復制代碼代碼如下:

public class MainActivity extends Activity implements SensorEventListener

step 2，得到距離感應器的實例

復制代碼代碼如下:

audioManager = (AudioManager) this
.getSystemService(Context.AUDIO_SERVICE);
mSensorManager = (SensorManager) getSystemService

(Context.SENSOR_SERVICE);
mSensor = mSensorManager.getDefaultSensor(Sensor.TYPE_PROXIMITY);

step 3，在onSensorChanged方法中判斷是否靠近聽筒

復制代碼代碼如下:

public void onSensorChanged(SensorEvent event) {
// TODO Auto-generated method stub
float range = event.values[0];

if (range == mSensor.getMaximumRange()) {
Toast.makeText(this, "正常模式", Toast.LENGTH_LONG).show();
} else {
Toast.makeText(this, "聽筒模式", Toast.LENGTH_LONG).show();
}

step 4, 向SensorManager注冊監聽距離感應器

復制代碼代碼如下:

@Override
protected void onResume() {
  mSensorManager.registerListener(this, mSensor,
    SensorManager.SENSOR_DELAY_NORMAL);
  super.onResume();
}
@Override
protected void onPause() {
  mSensorManager.unregisterListener(this);
  super.onPause();
}

二、根據距離感應器改變AudioManager播放模式
默認情況下，播放語音都是用外置喇叭或者耳機，我們需要編碼實現播放的切換。

step 1，在AndroidManifest文件中添加權限聲明

復制代碼代碼如下:

<uses-permission android:name="android.permission.MODIFY_AUDIO_SETTINGS" />

step 2，切換播放模式

復制代碼代碼如下:

public void onSensorChanged(SensorEvent event) {
// TODO Auto-generated method stub
float range = event.values[0];

  if (range == mSensor.getMaximumRange()) {
   Toast.makeText(this, "正常模式", Toast.LENGTH_LONG).show();
    audioManager.setMode(AudioManager.MODE_NORMAL);
  } else {
   Toast.makeText(this, "聽筒模式", Toast.LENGTH_LONG).show();
    audioManager.setMode(AudioManager.MODE_IN_CALL);
  }

完整代碼：

復制代碼代碼如下:

package com.markjoker.sensortest;

import java.io.FileInputStream;
import java.io.IOException;

import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
import android.media.AudioManager;
import android.media.MediaPlayer;
import android.os.Bundle;
import android.app.Activity;
import android.content.Context;
import android.util.Log;
import android.view.Menu;
import android.widget.Toast;

public class MainActivity extends Activity implements SensorEventListener {
private AudioManager audioManager;
private SensorManager mSensorManager;
private Sensor mSensor;

@Override
protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);
  init();
}

private void init() {
  audioManager = (AudioManager) this
    .getSystemService(Context.AUDIO_SERVICE);
  mSensorManager = (SensorManager) getSystemService(Context.SENSOR_SERVICE);
  mSensor = mSensorManager.getDefaultSensor(Sensor.TYPE_PROXIMITY);

  MediaPlayer mPlayer = new MediaPlayer();
  try {
   mPlayer.reset();
   mPlayer.setDataSource(new FileInputStream("/sdcard/snow.mp3").getFD());
   mPlayer.prepare();
   mPlayer.start();
  } catch (IllegalArgumentException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  } catch (SecurityException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  } catch (IllegalStateException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  } catch (IOException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  }
}