public static String showFileSize(long size) {
 String fileSize;
 if (size < KB)
  fileSize = size + "B";
 else if (size < MB)
  fileSize = String.format("%.1f", size / KB) + "KB";
 else if (size < GB)
  fileSize = String.format("%.1f", size / MB) + "MB";
 else
  fileSize = String.format("%.1f", size / GB) + "GB";

 return fileSize;
 }

 /** 顯示SD卡剩余空間 */
 public static String showFileAvailable() {
 String result = "";
 if (Environment.MEDIA_MOUNTED.equals(Environment.getExternalStorageState())) {
  StatFs sf = new StatFs(Environment.getExternalStorageDirectory().getPath());
  long blockSize = sf.getBlockSize();
  long blockCount = sf.getBlockCount();
  long availCount = sf.getAvailableBlocks();
  return showFileSize(availCount * blockSize) + " / " + showFileSize(blockSize * blockCount);
 }
 return result;

 } 

 

if (!mHistory.contains(url))
  mHistory.add(0, url); 

 /** 刪除文件 */
 private void deleteFile(final FileAdapter adapter, final PFile f, final int position) {
 new AlertDialog.Builder(getActivity()).setIcon(android.R.drawable.ic_dialog_alert).setTitle(R.string.file_delete).setMessage(getString(R.string.file_delete_confirm, f.title)).setNegativeButton(android.R.string.yes, new DialogInterface.OnClickListener() {
  @Override
  public void onClick(DialogInterface dialog, int which) {
  try {
   File file = new File(f.path);
   if (file.canRead() && file.exists())
   file.delete();
   FileBusiness.deleteFile(getActivity(), f);
   adapter.delete(position);
  } catch (Exception e) {

  }
  }

 }).setPositiveButton(android.R.string.no, null).show();
 }

 /** 重命名文件 */
 private void renameFile(final FileAdapter adapter, final PFile f, final int position) {
 final EditText et = new EditText(getActivity());
 et.setText(f.title);
 new AlertDialog.Builder(getActivity()).setTitle(R.string.file_rename).setIcon(android.R.drawable.ic_dialog_info).setView(et).setNegativeButton(android.R.string.yes, new DialogInterface.OnClickListener() {

  @Override
  public void onClick(DialogInterface dialog, int which) {
  String name = et.getText().toString().trim();
  if (name == null || name.trim().equals("") || name.trim().equals(f.title))
   return;

  try {
   File fromFile = new File(f.path);
   File nf = new File(fromFile.getParent(), name.trim());
   if (nf.exists()) {
   Toast.makeText(getActivity(), R.string.file_rename_exists, Toast.LENGTH_LONG).show();
   } else if (fromFile.renameTo(nf)) {
   f.title = name;
   f.path = nf.getPath();
   FileBusiness.renameFile(getActivity(), f);
   adapter.notifyDataSetChanged();
   }
  } catch (SecurityException se) {
   Toast.makeText(getActivity(), R.string.file_rename_failed, Toast.LENGTH_LONG).show();
  }
  }

 }).setPositiveButton(android.R.string.no, null).show();
 }