音频放播器

<SeekBar
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:id="@+id/sb_mian_bar"
    />
    <ImageButton
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:src="@android:drawable/ic_media_play"
        android:onClick="playorpause"
        />

import android.media.AudioManager;
import android.media.MediaPlayer;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.ImageButton;
import android.widget.SeekBar;

import java.io.IOException;

public class MainActivity extends AppCompatActivity {

    private ImageButton imageButton;
    private MediaPlayer mediaPlayer;
    private SeekBar sb_mian_bar;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        sb_mian_bar = (SeekBar) findViewById(R.id.sb_mian_bar);
        //给进度条设置滑动监听
        sb_mian_bar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
            @Override
            public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {

            }

            @Override
            public void onStartTrackingTouch(SeekBar seekBar) {

            }

            @Override
            public void onStopTrackingTouch(SeekBar seekBar) {
                //获取当前进度条的位置
                int currtentposition=seekBar.getProgress();
                //跳到某位置进行放播
                mediaPlayer.seekTo(currtentposition);
            }
        });
    }
    public void playorpause(View view){
        imageButton = (ImageButton) view;
        if(mediaPlayer==null){
//            mediaPlayer = MediaPlayer.create(this, R.raw.s2);
            if(Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)){
                String sdPath=Environment.getExternalStorageDirectory().getAbsolutePath();
               mediaPlayer=new MediaPlayer();
                mediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
                try {
                    mediaPlayer.setDataSource(this, Uri.parse("file://"+sdPath+"s1.mp3"));
                    mediaPlayer.prepareAsync();
                } catch (IOException e) {
                    e.printStackTrace();
                }
                mediaPlayer.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {
                    @Override
                    public void onPrepared(MediaPlayer mp) {
                        imageButton.setImageResource(android.R.drawable.ic_media_pause);
                        int time=mediaPlayer.getDuration();
                        sb_mian_bar.setMax(time);//设置进度条最大值为音乐的时间
                        new mythread().start();
                    }
                });
            }

        }else if (mediaPlayer.isPlaying()){
            mediaPlayer.pause();
            imageButton.setImageResource(android.R.drawable.ic_media_play);
        }else {
            mediaPlayer.start();
           imageButton.setImageResource(android.R.drawable.ic_media_pause);
        }
    }
    class  mythread extends Thread{
        @Override
        public void run() {
            super.run();
            while(sb_mian_bar.getProgress()<sb_mian_bar.getMax()){
                     //获取当前音乐的播放位置
                int  currentposition=mediaPlayer.getCurrentPosition();
                sb_mian_bar.setProgress(currentposition);

            }
        }
    }
}
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.g160628_android_y227_music">
    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"></uses-permission>
    <application android:allowBackup="true" android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name" android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true" android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>
</manifest>
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