public boolean changeDeleteVisible() {
   this.deleteVisible = !deleteVisible;
   if (!deleteVisible) { //// 重置多选框状态
     for (DownLoadInfo downInfo : list) {
       if (downInfo.isDelete()) downInfo.setDelete(false);
     }
   }
   notifyDataSetChanged();
   return deleteVisible;
 }
 public void setDeleteAllList(Button deleteall) { // 将所有数据标记为可删除
   boolean delete = getNotSelete(); // 含有未被选中的则全选  如果已经被全选则全部取消
   if (delete) deleteall.setText(mContext.getString(R.string.notselectall));
   else deleteall.setText(mContext.getString(R.string.selectall));
   for (DownLoadInfo downInfo : list) downInfo.setDelete(delete);
   notifyDataSetChanged();
   Message message = new Message();
   message.what = DELETElAYOUT;
   message.obj = getSeleteCount();
   handler.sendMessage(message);
 }