1、音频播放

为了保证当前只有一首歌曲播放，创建一个MediaPlayer的工具类，使用单例模式创建，但是为了节省资源，我们需要采用懒汉式去创建

工具类胆码

package com.example.day8_medioplayer;import android.media.MediaPlayer;import java.io.IOException;
import java.util.ArrayList;public class MedioPlayerUtils {MediaPlayer mediaPlayer;public static MedioPlayerUtils medioPlayerUtils;ArrayList<Music> list = new ArrayList();int index = 0;public static final int NEXT = 0;//下一首public static final int DAN = 1;//单曲循环public static final int RAN = 2;//随机播放int type = 0;//当前播放歌曲类型// TODO 构造私有化private MedioPlayerUtils() {//确保只有一个MediaPlayer对象mediaPlayer = new MediaPlayer();mediaPlayer.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {@Overridepublic void onCompletion(MediaPlayer mp) {switch (type) {case NEXT:next();break;case DAN:setDataSource(index);break;case RAN:int ran = (int) (Math.random() * list.size());index = ran;next();break;}}});}// TODO 获取工具类对象public static MedioPlayerUtils getInstnce() {if (medioPlayerUtils == null) {synchronized (String.class) {if (medioPlayerUtils == null) {medioPlayerUtils = new MedioPlayerUtils();}}}return medioPlayerUtils;}// TODO 设置播放模式public int setType() {switch (type) {case NEXT:type = DAN;break;case DAN:type = RAN;break;case RAN:type = NEXT;break;}return type;}// TODO 设置资源的方法public void setDataSource(int position) {try {mediaPlayer.reset();//重置mediaPlayer.setDataSource(list.get(position).getData());//设置资源mediaPlayer.prepare();//准备mediaPlayer.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {@Overridepublic void onPrepared(MediaPlayer mp) {mediaPlayer.start();}});index = position;} catch (IOException e) {e.printStackTrace();}}// TODO 开始播放public void start() {if (mediaPlayer != null) {mediaPlayer.start();}}// TODO 暂停播放public void pause() {if (mediaPlayer != null) {mediaPlayer.pause();}}// TODO 下一首public void next() {index++;if (index >= list.size() - 1) {index = 0;}setDataSource(index);}// TODO 上一首public void pre() {index--;if (index <= 0) {index = list.size() - 1;}setDataSource(index);}// TODO 判断当前是否播放public boolean isPlaying() {if (mediaPlayer != null) {boolean playing = mediaPlayer.isPlaying();return playing;}return false;}// TODO 设置资源集合public void setList(ArrayList<Music> list) {this.list = list;}// TODO 获取歌曲总时长public long getDuration() {long duration = 0;if (mediaPlayer != null) {duration = mediaPlayer.getDuration();}return duration;}// TODO 获取歌曲当前时长public long getCurrentPosition() {long currentPosition = 0;if (mediaPlayer != null) {currentPosition = mediaPlayer.getCurrentPosition();}return currentPosition;}// TODO 修改歌曲当前进度public void seekTo(int msec) {if (mediaPlayer != null) {mediaPlayer.seekTo(msec);}}// TODO 返回当前歌手public String getArtist() {if (mediaPlayer != null) {String artist = list.get(index).getArtist();return artist;}return null;}// TODO 返回当前歌曲public String getTitle() {if (mediaPlayer != null) {String title = list.get(index).getTitle();return title;}return null;}}

2、视频播放

用MediaPlayer去播放视频，需要采用方法将SurfaceView和MediaPlayer绑定在一起

 @Overridepublic void surfaceCreated(SurfaceHolder holder) {MedUtils.mediaPlayer.setDisplay(surfaceHolder);}

3、横竖屏切换

		//LANDSCAPE 山  横屏    PORTRAIT 肖像 竖if (getResources().getConfiguration().orientation == Configuration.ORIENTATION_LANDSCAPE) {//横屏setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);//竖屏} else if (getResources().getConfiguration().orientation == Configuration.ORIENTATION_PORTRAIT) {//竖屏setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);//横屏}

4、动态获取权限

	 String[] strings = new String[]{Manifest.permission.INTERNET};//判断安卓手机版本是否大于23，也就是安卓6.0以上if(Build.VERSION.SDK_INT>=Build.VERSION_CODES.M){//循环权限数组，授权for(int i=0;i<strings.length;i++){int permission = ActivityCompat.checkSelfPermission(this, strings[i]);if(permission== PackageManager.PERMISSION_DENIED){requestPermissions(strings,101);}}}