<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".MainActivity">


    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_weight="8"
        android:background="#FF4D60"
        >
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="登录"
            android:textSize="40dp"
            android:textColor="#fff"
            android:layout_centerHorizontal="true"
            android:layout_centerVertical="true"
            />
    </RelativeLayout>
    <RelativeLayout
         android:layout_width="match_parent"
         android:layout_height="match_parent"
         android:layout_weight="1"
         >
         
        <ImageView
            android:layout_width="80dp"
            android:layout_height="80dp"
            android:layout_centerHorizontal="true"
            android:layout_marginTop="60dp"
            android:src="@mipmap/ic_launcher"
            android:id="@+id/headimg"
            />

        <EditText
            android:layout_width="match_parent"
            android:layout_height="60dp"
            android:layout_marginLeft="60dp"
            android:layout_marginRight="60dp"
            android:background="@drawable/ruan"
            android:layout_below="@+id/headimg"
            android:layout_marginTop="30dp"
            android:id="@+id/username"
            android:hint="在？输一下名字？"
            />

        <EditText
            android:layout_width="match_parent"
            android:layout_height="60dp"
            android:layout_marginLeft="60dp"
            android:layout_marginRight="60dp"
            android:layout_marginTop="30dp"
            android:background="@drawable/ruan"
            android:layout_below="@+id/username"
            android:id="@+id/passwords"
            android:hint="为什么不输入密码？？？？"
            />
        <Button
            android:layout_width="match_parent"
            android:layout_height="60dp"
            android:layout_marginLeft="60dp"
            android:layout_marginRight="60dp"
            android:layout_below="@+id/passwords"
            android:text="点击注册"
            android:layout_marginTop="30dp"
            android:background="@drawable/ruaner"
            android:textColor="#fff"
            android:id="@+id/logbtn"
            />
        <Button
            android:layout_width="match_parent"
            android:layout_height="60dp"
            android:layout_marginLeft="60dp"
            android:layout_marginRight="60dp"
            android:layout_below="@+id/logbtn"
            android:text="点击登录"
            android:layout_marginTop="30dp"
            android:background="@drawable/ruaner"
            android:textColor="#fff"
            android:id="@+id/gogobtn"
            />
    </RelativeLayout>
</LinearLayout>





public class MainActivity extends AppCompatActivity {
    
    

    private ImageView headimg;
    private EditText username;
    private EditText passwords;
    private Button logbtn;
    private Button gogobtn;

    @Override
    protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
    
    
        super.onActivityResult(requestCode, resultCode, data);

        if (requestCode == 100 || resultCode == 101){
    
    
            username.setText(data.getStringExtra("names"));
            passwords.setText(data.getStringExtra("pwds"));
        }
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
    
    
        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);
        headimg = (ImageView) findViewById(R.id.headimg);
        username = (EditText) findViewById(R.id.username);
        passwords = (EditText) findViewById(R.id.passwords);
        logbtn = (Button) findViewById(R.id.logbtn);
        gogobtn = (Button) findViewById(R.id.gogobtn);


       gogobtn.setOnClickListener(new View.OnClickListener() {
    
    
           @Override
           public void onClick(View view) {
    
    
               String s = username.getText().toString();
               String s1 = passwords.getText().toString();
               Intent intent = new Intent(MainActivity.this, Main3Activity.class);
               startActivity(intent);
           }
       });
    }
}






public class MusicAdapter extends BaseAdapter {
    
    

    private List<Music> lists;
    private Context context;

    public MusicAdapter(List<Music> list, Context context) {
    
    
        this.lists = list;
        this.context = context;
    }

    @Override
    public int getCount() {
    
    
        return lists.size();
    }

    @Override
    public Object getItem(int i) {
    
    
        return lists.get(i);
    }

    @Override
    public long getItemId(int i) {
    
    
        return i;
    }

    @Override
    public View getView(int i, View view, ViewGroup viewGroup) {
    
    

        ViewHolder holder = null;
        if (view == null){
    
    
            holder = new ViewHolder();
            view = View.inflate(context, R.layout.song_layout,null);
            holder.text_artist = view.findViewById(R.id.text_artist);
            holder.text_duration = view.findViewById(R.id.text_duration);
            holder.text_title = view.findViewById(R.id.text_title);
            view.setTag(holder);
        }else {
    
    
            holder = (ViewHolder) view.getTag();
        }
        holder.text_title.setText(lists.get(i).getTitle());
        holder.text_duration.setText(lists.get(i).getDuration());
        holder.text_artist.setText(lists.get(i).getArtist());
        return view;
    }

    private class ViewHolder{
    
    
        private TextView text_title,text_artist,text_duration;
    }
}






public class MusicUtil {
    
    

    public static List<Music> getMusic(Context context){
    
    

        List<Music> lists = new ArrayList<>();
        Uri uri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;

        ContentResolver contentResolver = context.getContentResolver();

        Cursor cursor = contentResolver.query(uri, null, null, null, null);
        if (cursor != null){
    
    
            while (cursor.moveToNext()){
    
    

                String title = cursor.getString(cursor.getColumnIndex(MediaStore.Audio.Media.TITLE));
                String artist = cursor.getString(cursor.getColumnIndex(MediaStore.Audio.Media.ARTIST));
                String duration = cursor.getString(cursor.getColumnIndex(MediaStore.Audio.Media.DURATION));
                String data = cursor.getString(cursor.getColumnIndex(MediaStore.Audio.Media.DATA));
                String size = cursor.getString(cursor.getColumnIndex(MediaStore.Audio.Media.SIZE));
                Music music = new Music(title, artist, duration, data, size);
                lists.add(music);

            }
            cursor.close();
            return lists;
        }

        return null;
    }
}






public class Main4Activity extends AppCompatActivity {
    
    

    private static final String TAG = "MainActivity";
    private List<Music> lists;
    private MusicAdapter adapter;
    private ListView listView;
    private MediaPlayer mediaPlayer;
    private SeekBar seek;
    private Timer timer = new Timer();
    private int index = 0;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
    
    
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main4);

        seek = findViewById(R.id.seek);
        listView = findViewById(R.id.listView);

        seek.setProgress(0);
        mediaPlayer = new MediaPlayer();
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M){
    
    
            requestPermissions(new String[]{
    
    Manifest.permission.WRITE_EXTERNAL_STORAGE,Manifest.permission.READ_EXTERNAL_STORAGE},1);
        }

        seek.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
    
    
            @Override
            public void onProgressChanged(SeekBar seekBar, int i, boolean b) {
    
    
                if (b == true){
    
    
                    mediaPlayer.seekTo(i);
                }
            }

            @Override
            public void onStartTrackingTouch(SeekBar seekBar) {
    
    

            }

            @Override
            public void onStopTrackingTouch(SeekBar seekBar) {
    
    

            }
        });

        lists = new MusicUtil().getMusic(this);
        Log.i(TAG, "" + lists);
        adapter = new MusicAdapter(lists, this);
        listView.setAdapter(adapter);

        listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
    
    
            @Override
            public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
    
    
                index = i;
                seek.setProgress(0);
                mediaPlayer.reset();
                try {
    
    
                    seek.setMax(Integer.parseInt(lists.get(i).getDuration()));
                    mediaPlayer.setDataSource(lists.get(i).getData());
                    mediaPlayer.prepare();
                    mediaPlayer.start();
                } catch (IOException e) {
    
    
                    e.printStackTrace();
                }
            }
        });
        timer.schedule(new TimerTask() {
    
    
            @Override
            public void run() {
    
    
                seek.setProgress(mediaPlayer.getCurrentPosition());
            }
        },0,1000);
    }

    public void click(View view) {
    
    

        switch (view.getId()){
    
    
            case R.id.button_start:
                mediaPlayer.start();
                break;

            case R.id.button_pause:
                mediaPlayer.pause();
                break;

            case R.id.button_last:
                index--;
                mediaPlayer.reset();
                try {
    
    
                    mediaPlayer.setDataSource(lists.get(index).getData());

                    mediaPlayer.prepare();
                    mediaPlayer.start();
                } catch (IOException e) {
    
    
                    e.printStackTrace();
                }
                break;

            case R.id.button_next:
                index++;
                mediaPlayer.reset();
                try {
    
    
                    mediaPlayer.setDataSource(lists.get(index).getData());
                    mediaPlayer.prepare();
                    mediaPlayer.start();
                } catch (IOException e) {
    
    
                    e.printStackTrace();
                }
                break;
        }
    }
}