/// <summary>
/// 获取上传文件随机文件名，返回绝对路径地址
/// </summary>
/// <param name="extName">扩展名【请包含 . 】</param>
/// <param name="virtualPathName">虚路径名(包括文件名称)【/upload/..../filename.ext】</param>
/// <param name="fileName">文件名带扩展名</param>
/// <returns></returns>
public static string GetUploadRandFileName(string extName, out string virtualPathName, out string fileName)
{
return(UploadFile.GetUploadRandFileName(GetVirtualDir(), extName, out virtualPathName, out fileName));
}