/**
   * @param origPath 源图片文件路径
   * @param width 缩略图设定宽度
   * @param height 缩略图设定高度
   * @return 返回缩略图,失败返回null
   */
  public Bitmap getImageThumbFromMK(String origPath, int width, int height) {

    // 产生缩略图,并把该文件存到指定目录下,更新数据库中图片信息
    Bitmap thumbnail = null;
    Log.d(TAG, origPath + ":make thumbnail and insert message in database");
    ThumbnailCreator mCreator = new ThumbnailCreator(width, height);
    thumbnail = mCreator.createThumbnail(origPath);
    if (thumbnail == null) {
      return null;
    }
    String name = null;
    try {
      name = origPath.substring(origPath.lastIndexOf("/") + 1, origPath.lastIndexOf("."));
    } catch (IndexOutOfBoundsException e) {
      e.printStackTrace();
      return null;
    }
    try {
      File f = new File(imageDB.getAppDir() + "/" + name);
      FileOutputStream fOut = null;
      fOut = new FileOutputStream(f);
      thumbnail.compress(Bitmap.CompressFormat.JPEG, 100, fOut);
      fOut.flush();
      fOut.close();
      imageDB.insert(origPath, f.getPath());
    } catch (Exception e) {
      // TODO Auto-generated catch block
      Log.d(TAG, "create temp file false");
      e.printStackTrace();
    }
    return thumbnail;
  }