public class FragmentFile extends FragmentBase implements OnItemClickListener {

 private FileAdapter mAdapter;
 private TextView first_letter_overlay;
 private ImageView alphabet_scroller;

 @Override
 public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
 View v = super.onCreateView(inflater, container, savedInstanceState);
 // ~~~~~~~~~ 绑定控件
 first_letter_overlay = (TextView) v.findViewById(R.id.first_letter_overlay);
 alphabet_scroller = (ImageView) v.findViewById(R.id.alphabet_scroller);

 // ~~~~~~~~~ 绑定事件
 alphabet_scroller.setClickable(true);
 alphabet_scroller.setOnTouchListener(asOnTouch);
 mListView.setOnItemClickListener(this);

 // ~~~~~~~~~ 加载数据
 if (new SQLiteHelper(getActivity()).isEmpty())
 new ScanVideoTask().execute();
 else
 new DataTask().execute();

 return v;
 }

 /** 单击启动播放 */
 @Override
 public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
 final PFile f = mAdapter.getItem(position);
 Intent intent = new Intent(getActivity(), VideoViewDemo.class);
 intent.putExtra("path", f.path);
 startActivity(intent);
 }

 private class DataTask extends AsyncTask<Void, Void, ArrayList<PFile>> {

 @Override
 protected void onPreExecute() {
 super.onPreExecute();
 mLoadingLayout.setVisibility(View.VISIBLE);
 mListView.setVisibility(View.GONE);
 }

 @Override
 protected ArrayList<PFile> doInBackground(Void... params) {
 return FileBusiness.getAllSortFiles(getActivity());
 }

 @Override
 protected void onPostExecute(ArrayList<PFile> result) {
 super.onPostExecute(result);

 mAdapter = new FileAdapter(getActivity(), FileBusiness.getAllSortFiles(getActivity()));
 mListView.setAdapter(mAdapter);

 mLoadingLayout.setVisibility(View.GONE);
 mListView.setVisibility(View.VISIBLE);
 }
 }

 /** 扫描SD卡 */
 private class ScanVideoTask extends AsyncTask<Void, File, ArrayList<PFile>> {
 private ProgressDialog pd;
 private ArrayList<File> files = new ArrayList<File>();

 @Override
 protected void onPreExecute() {
 super.onPreExecute();
 pd = new ProgressDialog(getActivity());
 pd.setMessage("正在扫描视频文件...");
 pd.show();
 }

 @Override
 protected ArrayList<PFile> doInBackground(Void... params) {
 // ~~~ 遍历文件夹
 eachAllMedias(Environment.getExternalStorageDirectory());

 // ~~~ 入库
 SQLiteHelper sqlite = new SQLiteHelper(getActivity());
 SQLiteDatabase db = sqlite.getWritableDatabase();
 try {
 db.beginTransaction();

 SQLiteStatement stat = db.compileStatement("INSERT INTO files(" + FilesColumns.COL_TITLE + "," + FilesColumns.COL_TITLE_PINYIN + "," + FilesColumns.COL_PATH + "," + FilesColumns.COL_LAST_ACCESS_TIME + ") VALUES(?,?,?,?)");
 for (File f : files) {
 String name = FileUtils.getFileNameNoEx(f.getName());
 int index = 1;
 stat.bindString(index++, name);//title
 stat.bindString(index++, PinyinUtils.chineneToSpell(name));//title_pinyin
 stat.bindString(index++, f.getPath());//path
 stat.bindLong(index++, System.currentTimeMillis());//last_access_time
 stat.execute();
 }
 db.setTransactionSuccessful();
 } catch (BadHanyuPinyinOutputFormatCombination e) {
 e.printStackTrace();
 } catch (Exception e) {
 e.printStackTrace();
 } finally {
 db.endTransaction();
 db.close();
 }

 // ~~~ 查询数据
 return FileBusiness.getAllSortFiles(getActivity());
 }

 @Override
 protected void onProgressUpdate(final File... values) {
 File f = values[0];
 files.add(f);
 pd.setMessage(f.getName());
 }

 /** 遍历所有文件夹，查找出视频文件 */
 public void eachAllMedias(File f) {
 if (f != null && f.exists() && f.isDirectory()) {
 File[] files = f.listFiles();
 if (files != null) {
 for (File file : f.listFiles()) {
 if (file.isDirectory()) {
 eachAllMedias(file);
 } else if (file.exists() && file.canRead() && FileUtils.isVideoOrAudio(file)) {
 publishProgress(file);
 }
 }
 }
 }
 }

 @Override
 protected void onPostExecute(ArrayList<PFile> result) {
 super.onPostExecute(result);
 mAdapter = new FileAdapter(getActivity(), result);
 mListView.setAdapter(mAdapter);
 pd.dismiss();
 }
 }

 private class FileAdapter extends ArrayAdapter<PFile> {

 public FileAdapter(Context ctx, ArrayList<PFile> l) {
 super(ctx, l);
 }

 @Override
 public View getView(int position, View convertView, ViewGroup parent) {
 final PFile f = getItem(position);
 if (convertView == null) {
 final LayoutInflater mInflater = getActivity().getLayoutInflater();
 convertView = mInflater.inflate(R.layout.fragment_file_item, null);
 }
 ((TextView) convertView.findViewById(R.id.title)).setText(f.title);
 return convertView;
 }

 }

 /**
 * A-Z
 */
 private OnTouchListener asOnTouch = new OnTouchListener() {

 @Override
 public boolean onTouch(View v, MotionEvent event) {
 switch (event.getAction()) {
 case MotionEvent.ACTION_DOWN:// 0
 alphabet_scroller.setPressed(true);
 first_letter_overlay.setVisibility(View.VISIBLE);
 mathScrollerPosition(event.getY());
 break;
 case MotionEvent.ACTION_UP:// 1
 alphabet_scroller.setPressed(false);
 first_letter_overlay.setVisibility(View.GONE);
 break;
 case MotionEvent.ACTION_MOVE:
 mathScrollerPosition(event.getY());
 break;
 }
 return false;
 }
 };

 /**
 * 显示字符
 * 
 * @param y
 */
 private void mathScrollerPosition(float y) {
 int height = alphabet_scroller.getHeight();
 float charHeight = height / 28.0f;
 char c = 'A';
 if (y < 0)
 y = 0;
 else if (y > height)
 y = height;

 int index = (int) (y / charHeight) - 1;
 if (index < 0)
 index = 0;
 else if (index > 25)
 index = 25;

 String key = String.valueOf((char) (c + index));
 first_letter_overlay.setText(key);

 int position = 0;
 if (index == 0)
 mListView.setSelection(0);
 else if (index == 25)
 mListView.setSelection(mAdapter.getCount() - 1);
 else {
 for (PFile item : mAdapter.getAll()) {
 if (item.title_pinyin.startsWith(key)) {
 mListView.setSelection(position);
 break;
 }
 position++;
 }
 }
 }