2018-03-19 音乐播放器(一)

笔记如下

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2018-03-19_114320.png

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播放音乐的代码

            player = new MediaPlayer();
            //设置播放的资源
            player.setDataSource(path);

            player.prepare();//准备播放
            player.start();//开始播放

进度条跟随音乐播放滑动

        skb_progress.setMax(player.getDuration());//获取音乐文件的时长
        //实现进度条

        //获得当前的进度
        //更新UI
        //获得当前的进度
        //更新UI
        new Thread(new Runnable() {
            @Override
            public void run() {
                System.out.println(player.toString());
                while (player != null) {
                    if (!tracking) {
                        //获得当前的进度
                        int currentPosition = player.getCurrentPosition();
                        skb_progress.setProgress(currentPosition);//更新UI
                    }

                }

            }
        }).start();

音乐暂停的方法

    //暂停
    public void pause(View v){

        if (player != null && player.isPlaying()){
            System.out.println(player.isPlaying());
            player.pause();
            ((Button)v).setText("继续");
        }else if(player != null){
            player.start();
            performProgress();
            ((Button)v).setText("暂停");
        }

    }
    
    

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源码:

package com.chen.player_asynchronous;

import android.Manifest;
import android.content.pm.PackageManager;
import android.media.MediaPlayer;
import android.os.Bundle;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v7.app.AppCompatActivity;
import android.text.TextUtils;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.SeekBar;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity implements SeekBar.OnSeekBarChangeListener {

    private EditText et_path;
    private SeekBar skb_progress;
    private MediaPlayer player;
    private boolean tracking = false;



    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        et_path = (EditText) findViewById(R.id.et_path);
        skb_progress = (SeekBar) findViewById(R.id.skb_progerss);
        requestPermission();

        skb_progress.setOnSeekBarChangeListener(this);


    }

    private void requestPermission(){
        if (ContextCompat.checkSelfPermission(this,
                Manifest.permission.READ_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED){ //表示未授权时
            //进行授权
            ActivityCompat.requestPermissions(this,new String[]{Manifest.permission.READ_EXTERNAL_STORAGE},1);
        }else{
            //调用打电话的方法
            Toast.makeText(this, "权限获取了...", Toast.LENGTH_SHORT).show();
        }
    }

    //播放
    public void play(View v){
        tracking = false;
        String path = et_path.getText().toString().trim();
        if (TextUtils.isEmpty(path)){
            return;
        }

        //播放音乐
        if (player == null){

            player = new MediaPlayer();
        }
        //重置播放器
        player.reset();
        try {
            //可能会报错的异常
            player.setOnErrorListener(new MediaPlayer.OnErrorListener() {
                @Override
                public boolean onError(MediaPlayer mp, int what, int extra) {
                    System.out.println("what :" + what);
                    return false;
                }
            });
            //设置播放的资源
            player.setDataSource(path);

            player.prepare();//准备播放
            player.start();//开始播放

            //进度条的方法
            performProgress();


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

    }

    private void performProgress() {
        skb_progress.setMax(player.getDuration());//获取音乐文件的时长
        //实现进度条

        //获得当前的进度
        //更新UI
        //获得当前的进度
        //更新UI
        new Thread(new Runnable() {
            @Override
            public void run() {
                System.out.println(player.toString());
                while (player != null) {
                    if (!tracking) {
                        //获得当前的进度
                        int currentPosition = player.getCurrentPosition();
                        skb_progress.setProgress(currentPosition);//更新UI
                    }

                }

            }
        }).start();


    }

    //暂停
    public void pause(View v){

        if (player != null && player.isPlaying()){
            System.out.println(player.isPlaying());
            player.pause();
            ((Button)v).setText("继续");
        }else if(player != null){
            player.start();
            performProgress();
            ((Button)v).setText("暂停");
        }

    }


    //停止
    public void stop(View v){
        tracking = true;
        if (player != null){
            player.stop();
            player.release();//释放资源
            player = null;
        }

    }


    //seekbar的移动监听事件
    @Override
    public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {


    }

    @Override
    public void onStartTrackingTouch(SeekBar seekBar) {
        //开始拖动
        tracking = true;

    }

    @Override
    public void onStopTrackingTouch(SeekBar seekBar) {
        //结束拖动
        tracking = false;

        //播放到对应的位置
        if (player != null){
            player.seekTo(seekBar.getProgress());
        }

    }
}