笔记18 | 利用MediaRecorder简单实现录音

package com.example.book_mediarecorder;

import java.io.File;
import java.sql.Date;
import java.text.SimpleDateFormat;
import android.app.Activity;
import android.media.MediaRecorder;
import android.os.Bundle;
import android.os.Environment;
import android.os.Handler;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;

public class MainActivity extends Activity {

	Boolean isRecording=false;
	TextView rTimer;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		final Button button = (Button) findViewById(R.id.bRecourd);
		rTimer = (TextView) findViewById(R.id.rTimer);
		if (isRecording) {
			button.setText("正在录制中...");
		}else{
			button.setText("开始录制");
		}
		button.setOnClickListener(new OnClickListener() {

			@Override
			public void onClick(View v) {
				if (!isRecording) {
					isRecording=true;
					button.setText("正在录制中...");
					startRecord();
				}else{
					isRecording=false;
					button.setText("开始录制");
					stopRecord();
				}
			}
		});
	}

	private MediaRecorder mr=null; 
	int Count;
	//开始录制
	private void startRecord() {
		if (mr == null) {
			File dir = new File(Environment.getExternalStorageDirectory(), "sounds"); //创建音频存放的目录
			if (!dir.exists()) {
				dir.mkdirs();
			}
			File soundFile = new File(dir, getCurrentTime()+".amr"); //创建的音频名称
			if (!soundFile.exists()) {
				try {
					soundFile.createNewFile();
				} catch (Exception e) {
					e.printStackTrace();
				}
			}
			mr = new MediaRecorder();
			mr.setAudioSource(MediaRecorder.AudioSource.MIC);//拿到机器的MIC
			mr.setOutputFormat(MediaRecorder.OutputFormat.AMR_WB);//设置输出格式
			mr.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_WB);//设置编码格式
			mr.setOutputFile(soundFile.getAbsolutePath());
			try {
				mr.prepare();
				mr.start();
			} catch (Exception e) {
				e.printStackTrace();
			}
			Count = 0;
			handler = new Handler();
			runnable = new Runnable() {

				@Override
				public void run() {
					if (Count == 1800) {//限制录制时间1800s
						mr.stop();
						mr.release();
						mr = null;
					}
					Count ++;
					str = showTimeCount((long)Count)+"/30:00";
					rTimer.setText(str);
					if (handler!=null) {
						handler.postDelayed(this, 1000);
					}
				}
			};
			runnable.run();
		}
	}
	Handler handler;
	Runnable runnable ;
	String str;
	//停止录制
	private void stopRecord() {
		if (mr != null) {
			mr.stop();
			mr.release();
			mr = null;
		}
		str="";
		handler=null;
		runnable=null;
	}


	//获取当前时间，以其为名来保存录音  
	private String getCurrentTime(){  
		SimpleDateFormat format=new SimpleDateFormat("yyyyMMddHHmmss");  
		Date date=new Date(System.currentTimeMillis());  
		String str=format.format(date);  
		return str;  

	} 

	////将时间转为计时格式
	String showTimeCount(long time){
		String s = null;
		if (time <= 59) {
			s = "00:";
			return time<10 ? s+"0"+String.valueOf(time) : s+String.valueOf(time);
		}else{
			return (time%60 <10 ? s+"0"+String.valueOf(time) : s+String.valueOf(time))+ ":"+(time/60<10 ? s+"0"+String.valueOf(time) : s+String.valueOf(time));  
		}
	}


}

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