Check file size of an uploaded file

FileSizeCheck.cs

private const int DefaultFileSizeLimit = 3000000;
 
private int? _fileSizeLimitInBytes;
private int FileSizeLimitInBytes
{
    get
    {
        if (_fileSizeLimitInBytes == null || _fileSizeLimitInBytes == DefaultFileSizeLimit)
        {
            _fileSizeLimitInBytes = DefaultFileSizeLimit;
 
            Item fileUploadConfig = ItemNodes.SiteConfig.Children.FirstOrDefault(x => x.TemplateID == Enumerators.SitecoreConfig.Guids.Templates.FileUploadConfigId);
            if (fileUploadConfig != null && fileUploadConfig.Fields[Enumerators.SitecoreConfig.Fields.Global.ImageFileSizeLimit] != null
                && !string.IsNullOrEmpty(fileUploadConfig[Enumerators.SitecoreConfig.Fields.Global.ImageFileSizeLimit]))
            {
                int sizeInMegaBytes;
                bool success =
                    int.TryParse(fileUploadConfig[Enumerators.SitecoreConfig.Fields.Global.ImageFileSizeLimit],
                        out sizeInMegaBytes);
 
                if (success)
                    _fileSizeLimitInBytes = sizeInMegaBytes * 1000000;
 
            }
        }
 
        return _fileSizeLimitInBytes.Value;
    }
}
 
private bool ValidateFileSize(HttpPostedFile postedFile)
{
    var sizeInBytes = postedFile.ContentLength;
 
    return (sizeInBytes <= FileSizeLimitInBytes);
}