问题描述
**Main Activity.java**
这是我实例化所有方法/对象的主要活动。在这里，我使用 Dexter 库从用户的外部存储中获取文件，然后我制作了一种称为查找歌曲的方法，该方法有助于查找文件的路径并相应地列出它们。然后我做了另一种称为显示歌曲的方法，这将有助于获取歌曲的整体大小，然后相应地显示整个列表及其名称。然后在自定义适配器的帮助下，我通过了名为 item 的数组中的歌曲列表。
public class MainActivity extends AppCompatActivity {
ListView listView;
String [] items;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
listView = findViewById(R.id.listViewSong);
runtimePermission();
}
public void runtimePermission(){
Dexter.withContext(this)
.withPermissions(Manifest.permission.READ_EXTERNAL_STORAGE,Manifest
.permissi
on.RECORD_AUDIO)
.withListener(new MultiplePermissionsListener() {
@RequiresApi(api = Build.VERSION_CODES.R)
@Override
public void
onPermissionsChecked(MultiplePermissionsReport
multiplePermissionsReport)
{
displaySongs();
}
@Override
public void
onPermissionRationaleShouldBeShown(List<PermissionRequest> list,
PermissionToken permissionToken) {
permissionToken.continuePermissionRequest();
}
}).check();
}
public ArrayList<File> findSong(File file){
ArrayList arrayList = new ArrayList();
Log.d(TAG, "findSong:"+ file.getPath());
File [] files = file.listFiles();
if (files!=null) {
Log.d(TAG, "findSong:"+ files.length);
for (File singleFile : files) {
if (singleFile.isDirectory() && !singleFile.isHidden()) {
arrayList.addAll(findSong(singleFile));
} else {
if (singleFile.getName().endsWith(".mp3") &&
!singleFile.getName().startsWith(".")) {
arrayList.add(singleFile);
}
}
}
}
return arrayList;
}
public void displaySongs(){
ArrayList<File> mySongs =
findSong(Environment.getExternalStorageDirectory());
String [] items = new String [mySongs.size()];
if(mySongs == null)return; // this is very important function
otherwise app will crash
for (int i=0; i<mySongs.size(); i++){
items[i] = mySongs.get(i).getName().replace(".mp3",
"");
}
Log.d(TAG, "displaySongs:"+ items.length);
(this,
android.R.layout.simple_list_item_1,items);
CustomAdapter customAdapter = new CustomAdapter(this,
Arrays.asList(items));
Log.d(TAG, "displaySongs:"+ customAdapter.getCount());
listView.setAdapter(customAdapter);
listView.setOnItemClickListener(new
AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int
position, long id) {
String currentSong = (String)
listView.getItemAtPosition(position);
startActivity(new Intent(getApplicationContext(),
PlayerActivity.class)
.putExtra("currentSong", currentSong)
.putExtra("position",position)
.putExtra("songs",mySongs));
}
});
}
class CustomAdapter extends ArrayAdapter {
public android.util.Log Log;
List<String> names;
LayoutInflater inflater;
Context context;
public CustomAdapter(Context context, List<String> names) {
super(context,R.layout.list_item ,names);
this.names=names;
this.context=context;
}
@Override
public View getView(int position, View convertView, ViewGroup
parent) {
inflater=LayoutInflater.from(getContext()); //inflater is
responsible for taking your xml files that defines your layout
// and converting them into view objects.
View
customview=inflater.inflate(R.layout.list_item,parent,false);
String data=names.get(position);
//String data1=names.get(position+1);
TextView tv=
(TextView)customview.findViewById(R.id.textsongname);
tv.setText(data);
tv.setSelected(true);
//TextView tv1=(TextView)customview.findViewById(R.id.TeamB);
//tv1.setText(data1);
return customview;
}
}
}
**PlayerActivity.java**
我尝试创建一个名为 update seek bar 的线程，在我将 set 应用于单击栏更改侦听器之后，它将更新我的搜索栏到当前位置，以便每当用户更新侧边栏的位置时它应该得到更新。但是这里的错误是，当我在模拟器上使用此代码运行我的应用程序时，它的工作完全正常，但是当安装在我的手机中时，会出现 2 个错误。歌曲完成后，它不会自动跳到下一首歌曲，其次当用户更新侧边栏并按下下一步时，侧边栏不会到达位置 0，并且整个错误显示在我的手机上，而不是在模拟器中。
public class PlayerActivity extends AppCompatActivity {
Button play,next,fastforward, previous, fastrewind;
TextView txtsn, txtsstart, txtsstop;
SeekBar seekBar;
BarVisualizer visualizer;
Thread updateSeekBar;
String sName;
public static final String EXTRA_NAME = "song_name";
static MediaPlayer mediaPlayer;
int position;
ArrayList mySongs;
ImageView imageView;
@Override
public boolean onOptionsItemSelected(@NonNull MenuItem item) {
if (item.getItemId()== android.R.id.home){
onBackPressed();
}
return super.onOptionsItemSelected(item);
}
@Override
protected void onDestroy() {
if (visualizer != null){
visualizer.release();
}
super.onDestroy();
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_player);
getSupportActionBar().setTitle("Now Playing");
getSupportActionBar().setDisplayShowHomeEnabled(true);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
play = findViewById(R.id.play);
next = findViewById(R.id.next);
previous = findViewById(R.id.previous);
fastforward = findViewById(R.id.fastforward);
fastrewind = findViewById(R.id.fastrewind);
txtsn = findViewById(R.id.txtsn);
txtsstart = findViewById(R.id.txtsstart);
txtsstop = findViewById(R.id.txtsstop);
seekBar = findViewById(R.id.seekbar);
visualizer = findViewById(R.id.blast);
imageView = findViewById(R.id.iamgeView);
if (mediaPlayer != null){
mediaPlayer.stop();
mediaPlayer.release();
}
Intent intent = getIntent();
Bundle bundle = intent.getExtras();
mySongs = (ArrayList) bundle.getParcelableArrayList("songs");
sName = intent.getStringExtra("currentSong");
position = bundle.getInt("position",0);
txtsn.setText(sName);
txtsn.setSelected(true);
Uri uri = Uri.parse(mySongs.get(position).toString()); // uri is
usually use tell a content provider what we want to access by
reference
mediaPlayer = MediaPlayer.create(this,uri);
mediaPlayer.start();
seekBar.setMax(mediaPlayer.getDuration());
updateSeekBar = new Thread(){
@Override
public void run() {
int currentPosition = 0;
while (currentPosition<mediaPlayer.getDuration()){
try {
currentPosition = mediaPlayer.getCurrentPosition();
seekBar.setProgress(currentPosition);
sleep(500);
}
catch (Exception e) {
e.printStackTrace();
}
}
}
};
updateSeekBar.start();
seekBar.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) {
mediaPlayer.seekTo(seekBar.getProgress());
}
});
String endTime = createTime(mediaPlayer.getDuration());
txtsstop.setText(endTime);
final Handler handler = new Handler();
final int delay = 1000;
handler.postDelayed(new Runnable() {
@Override
public void run() {
String currentTime =
createTime(mediaPlayer.getCurrentPosition());
txtsstart.setText(currentTime);
handler.postDelayed(this,delay);
}
},delay);
play.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (mediaPlayer.isPlaying()){
play.setBackgroundResource(R.drawable.ic_play);
mediaPlayer.pause();
}
else {
play.setBackgroundResource(R.drawable.ic_pause);
mediaPlayer.start();
}
}
});
next.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
mediaPlayer.stop();
mediaPlayer.release();
if(position!=mySongs.size()-1){
position = position + 1;
}
else{
position = 0;
}
Uri uri = Uri.parse(mySongs.get(position).toString());
mediaPlayer = MediaPlayer.create(getApplicationContext(),
uri);
sName = mySongs.get(position).toString();
txtsn.setText(sName);
mediaPlayer.start();
play.setBackgroundResource(R.drawable.ic_pause);
seekBar.setMax(mediaPlayer.getDuration());
startAnimation(imageView);
int audiosessionId = mediaPlayer.getAudioSessionId();
if(audiosessionId!= -1){
visualizer.setAudioSessionId(audiosessionId);
}
}
});
mediaPlayer.setOnCompletionListener(new
MediaPlayer.OnCompletionListener() {
@Override
public void onCompletion(MediaPlayer mp) {
next.performClick();
}
});
int audiosessionId = mediaPlayer.getAudioSessionId();
if(audiosessionId!= -1){
visualizer.setAudioSessionId(audiosessionId);
}
previous.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
mediaPlayer.stop();
mediaPlayer.release();
if(position!=0){
position = position - 1;
}
else{
position = mySongs.size() - 1;
}
Uri uri = Uri.parse(mySongs.get(position).toString());
mediaPlayer = MediaPlayer.create(getApplicationContext(),
uri);
sName = mySongs.get(position).toString();
txtsn.setText(sName);
mediaPlayer.start();
play.setBackgroundResource(R.drawable.ic_pause);
seekBar.setMax(mediaPlayer.getDuration());
startAnimation(imageView);
int audiosessionId = mediaPlayer.getAudioSessionId();
if(audiosessionId!= -1){
visualizer.setAudioSessionId(audiosessionId);
}
}
});
fastforward.setOnClickListener(new View.OnClickListener()
{
@Override
public void onClick(View v) {
if (mediaPlayer.isPlaying()){
mediaPlayer.seekTo(mediaPlayer.getCurrentPosition()+1000);
}
}
});
fastrewind.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (mediaPlayer.isPlaying()){
mediaPlayer.seekTo(mediaPlayer.getCurrentPosition()-1000);
}
}
});
}
private boolean isPermissionGranted(){
if (Build.VERSION.SDK_INT == Build.VERSION_CODES.R){
return Environment.isExternalStorageManager();
}
else {
int readExternalStoragePermission =
ContextCompat.checkSelfPermission(this,
Manifest.permission.READ_EXTERNAL_STORAGE);
return readExternalStoragePermission ==
PackageManager.PERMISSION_GRANTED;
}
}
public void startAnimation(View view){
ObjectAnimator animator =
ObjectAnimator.ofFloat(imageView,"rotation",0f,360f);
animator.setDuration(1000);
AnimatorSet animatorSet = new AnimatorSet();
animatorSet.playTogether(animator);
animatorSet.start();
}
public String createTime(int duration) {
String time = "";
int min = duration/1000/60;
int sec = duration/1000%60;
time+=min+":";
if (sec<10) {
time+="0";
}
time+=sec;
return time;
}
}
标签： javaandroid