auto folder1="./.mm";

QDir \*folder = new QDir;

  bool exist = folder->exists(folder1);

  if(exist)

  {

      QMessageBox::warning(this, tr("createDir"), tr("Dir is already existed!"));

  }

  else

  {

      //创建文件夹

      bool ok = folder->mkdir(folder1);

      if(ok)

          QMessageBox::warning(this, tr("CreateDir"), tr("Create Dir success!"));

      else

          QMessageBox::warning(this, tr("CreateDir"), tr("Create Dir fail"));

  }

p, li { white-space: pre-wrap }