一、利用距离感应器监听听筒靠近耳朵事件

准确的说距离感应器并不能监听到你是否把手机靠近耳朵，也许是你用手挡在了距离感应器前面，但这不是我们关心的，我们关心的是当你的耳朵靠近听筒时，我们要捕获到这个事件

step 1，新建实现SensorEventListener接口的类并实现onSensorChanged(SensorEvent event)方法

复制代码 代码如下:

public class MainActivity extends Activity implements SensorEventListener

step 2，得到距离感应器的实例

复制代码 代码如下:

audioManager = (AudioManager) this

.getSystemService(Context.AUDIO_SERVICE);

mSensorManager = (SensorManager) getSystemService

(Context.SENSOR_SERVICE);

mSensor = mSensorManager.getDefaultSensor(Sensor.TYPE_PROXIMITY);

step 3，在onSensorChanged方法中判断是否靠近听筒

复制代码 代码如下:

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, "听筒模式", Toast.LENGTH_LONG).show();

}

step 4, 向SensorManager注册监听距离感应器

复制代码 代码如下:

@Override

protected void onResume() {

mSensorManager.registerListener(this, mSensor,

SensorManager.SENSOR_DELAY_NORMAL);

super.onResume();

}

@Override

protected void onPause() {

mSensorManager.unregisterListener(this);

super.onPause();

}

二、根据距离感应器改变AudioManager播放模式

默认情况下，播放语音都是用外置喇叭或者耳机，我们需要编码实现播放的切换。

step 1，在AndroidManifest文件中添加权限声明

复制代码 代码如下:

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

step 2，切换播放模式

复制代码 代码如下:

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, "听筒模式", Toast.LENGTH_LONG).show();

audioManager.setMode(AudioManager.MODE_IN_CALL);

}

完整代码：

复制代码 代码如下:

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();

}

}

@Override

protected void onResume() {

mSensorManager.registerListener(this, mSensor,

SensorManager.SENSOR_DELAY_NORMAL);

super.onResume();

}

@Override

protected void onPause() {

// TODO Auto-generated method stub

mSensorManager.unregisterListener(this);

super.onPause();

}

@Override

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, "听筒模式", Toast.LENGTH_LONG).show();

audioManager.setMode(AudioManager.MODE_IN_CALL);

}

}

@Override

public void onAccuracyChanged(Sensor sensor, int accuracy) {

// TODO Auto-generated method stub

}

}