android studio手机MP3音乐播放器

package com.example.a29.myfourth; import android.Manifest; import android.content.Intent; import android.content.pm.PackageManager; import android.os.Build; import android.os.Handler; import android.os.Message; import android.support.annotation.NonNull; import android.support.v4.app.ActivityCompat; import android.support.v4.content.ContextCompat; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import android.view.View; import android.widget.AdapterView; import android.widget.ImageButton; import android.widget.ListView; import android.widget.SeekBar; import android.widget.TextView; import android.widget.Toast; import com.example.a29.myfourth.entity.MP3; import com.example.a29.myfourth.entity.SendData; import com.example.a29.myfourth.service.MusicService; import com.example.a29.myfourth.utils.MP3Adapter; import com.example.a29.myfourth.utils.MP3Utils; import java.util.List; public class MainActivity extends AppCompatActivity implements View.OnClickListener, SeekBar.OnSeekBarChangeListener, AdapterView.OnItemClickListener{ private static ImageButton img_prev=null,img_play=null,img_stop=null,img_next=null; private static SeekBar sb=null; private static TextView tv_title=null,tv_time=null; private ListView lv_music=null; private MP3Adapter mp3Adapter=null; public static List<MP3> mp3List=null; private boolean flag=false; private static int max=0,progress=0,index=0; public static Handler handler=new Handler(){ @Override public void handleMessage(Message msg){ switch (msg.what){ case 100: SendData sendData=(SendData) msg.obj; //当前位置 progress = sendData.progress; max=sendData.max; index=sendData.index; sb.setMax(max); sb.setProgress(progress); String str1=MP3Utils.timeParse(progress); String str2=MP3Utils.timeParse(max); tv_time.setText(str1+"/"+str2); String mp3=mp3List.get(index).getTitle(); tv_title.setText(mp3); break; case 200: int tt=msg.arg1; if(tt==1){ img_play.setImageResource(android.R.drawable.ic_media_pause); } if(tt==-1){ img_play.setImageResource(android.R.drawable.ic_media_play); } break; case 300: max=0; progress=0; img_play.setImageResource(android.R.drawable.ic_media_play); sb.setProgress(0); tv_time.setText("00:00/00:00"); tv_title.setText(""); } } }; private Handler handler2=new Handler(){ public void handleMessage(Message msg){ switch (msg.what){ case -100: moveTaskToBack(true); break; } } }; @Override public void onClick(View v) { int id=v.getId(); switch (id){ case R.id.img_prev: index--; progress=0; sendToService("prev",index,progress,true); img_play.setImageResource(android.R.drawable.ic_media_pause); break; case R.id.img_play: sendToService("play",index,progress,true); // Work ww=new Work(); // ww.start(); break; case R.id.img_stop: Intent tt=new Intent(MainActivity.this,MusicService.class); stopService(tt); img_play.setImageResource(android.R.drawable.ic_media_play); break; case R.id.img_next: index++; progress=0; sendToService("next",index,progress,true); img_play.setImageResource(android.R.drawable.ic_media_pause); break; } } @Override public void onItemClick(AdapterView<?> parent, View view, int position, long id) { index=position; progress=0; sendToService("click",index,progress,true); } @Override public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) { this.progress=progress; } @Override public void onStartTrackingTouch(SeekBar seekBar) { sendToService("change",index,progress,false); } @Override public void onStopTrackingTouch(SeekBar seekBar) { this.progress=sb.getProgress(); sendToService("change",index,progress,true); } @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); tv_time=(TextView)findViewById(R.id.tv_time); tv_title=(TextView)findViewById(R.id.tv_title); img_play=(ImageButton)findViewById(R.id.img_play); img_stop=(ImageButton)findViewById(R.id.img_stop); img_prev=(ImageButton)findViewById(R.id.img_prev); img_next=(ImageButton)findViewById(R.id.img_next); sb=(SeekBar)findViewById(R.id.sb); sb.setOnSeekBarChangeListener(this); img_play.setOnClickListener(this); img_stop.setOnClickListener(this); img_prev.setOnClickListener(this); img_next.setOnClickListener(this); lv_music=(ListView)findViewById(R.id.lv_music); checkRight(); if(flag==true) showAllMP3(); } //------------------------------------- //对权力进行检查 public void checkRight(){ if(Build.VERSION.SDK_INT>=Build.VERSION_CODES.M){ int p1= ContextCompat.checkSelfPermission(this, Manifest.permission.READ_EXTERNAL_STORAGE); int p2= PackageManager.PERMISSION_GRANTED; if(p1 != p2) { ActivityCompat.requestPermissions(this, new String[]{ Manifest.permission.READ_EXTERNAL_STORAGE },500); }else{ flag=true; } } } //对点击的值进行判断 @Override public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults){ if(requestCode==500){ if(grantResults[0]==PackageManager.PERMISSION_GRANTED){ flag=true; }else { Toast.makeText(MainActivity.this,"Permission Deniod",Toast.LENGTH_SHORT).show(); } } super.onRequestPermissionsResult(requestCode,permissions,grantResults); } private void showAllMP3(){ mp3List = MP3Utils.getAllMP3(this); if(mp3List!=null){ mp3Adapter=new MP3Adapter(this,R.layout.myitem,mp3List); lv_music.setAdapter(mp3Adapter); } else{ lv_music.setAdapter(null); } } private void sendToService(String act,int mm,int pp,boolean bb){ if(mp3List.size()>0){ Intent tt=new Intent(MainActivity.this, MusicService.class); tt.putExtra("action",act); tt.putExtra("index",mm); tt.putExtra("progress",pp); tt.putExtra("ok",bb); //启动后台服务 startService(tt); } } // private class Work extends Thread{ // public void run(){ // try