android吹一吹功能的实现，利用麦克风去监听频率的变化。

package com.li;

import android.media.AudioFormat;
import android.media.AudioRecord;
import android.media.MediaRecorder;
import android.os.Message;

//import com.bshark.letmessage.ui.BlowActivity.MyHandler;
//import com.bshark.letmessage.util.Parameter;

import com.li.BlowActivity.MyHandler;

public class RecordThread extends Thread {
private AudioRecord ar;
private int bs = 100;
private static int SAMPLE_RATE_IN_HZ = 8000;
private Message msg;
private int number = 1;
private int tal = 1;
private MyHandler handler;
private long currenttime;
private long endtime;
private long time = 1;

//到达该值之后 触发事件
private static int BLOW_ACTIVI=3000;

public RecordThread(MyHandler myHandler) {
super();
bs = AudioRecord.getMinBufferSize(SAMPLE_RATE_IN_HZ,
AudioFormat.CHANNEL_CONFIGURATION_MONO,
AudioFormat.ENCODING_PCM_16BIT);
ar = new AudioRecord(MediaRecorder.AudioSource.MIC, SAMPLE_RATE_IN_HZ,
AudioFormat.CHANNEL_CONFIGURATION_MONO,
AudioFormat.ENCODING_PCM_16BIT, bs);
handler = myHandler;
}

@Override
public void run() {
try {
ar.startRecording();
Parameter.isblow = true;
// 用于读取的 buffer
byte[] buffer = new byte[bs];
while (Parameter.isblow) {
number++;
sleep(8);
currenttime = System.currentTimeMillis();
int r = ar.read(buffer, 0, bs) + 1;
int v = 0;
for (int i = 0; i < buffer.length; i++) {
v += (buffer[i] * buffer[i]);
}
int value = Integer.valueOf(v / (int) r);
tal = tal + value;
endtime = System.currentTimeMillis();
time = time + (endtime - currenttime);

if (time >= 500 || number > 5) {

int total = tal / number;
if (total > BLOW_ACTIVI) {
//发送消息通知到界面 触发动画

//利用传入的handler 给界面发送通知
BlowActivity.i+=1;
handler.sendEmptyMessage(0); //改变i的值后，发送一个空message到主线程

//
number = 1;
tal = 1;
time = 1;
}
}

}
ar.stop();
ar.release();
bs=100;

} catch (Exception e) {
e.printStackTrace();
}
}
}