ActionFilterAttribute之CompressFilter,GZIP，DEFLATE压缩

开启Gzip,Deflate压缩也会给减小网站页面大小，进而减小使用带宽，只需设置此Filter标签，便可实现．其中当页面出现错误时，会禁止压缩，以防用户看不到调式错误．

public class CompressFilter : ActionFilterAttribute
    {
        #region = IsAvailable =
        private bool _isavailable = true;
        public bool IsAvailable
        {
            get { return _isavailable; }
            set { _isavailable = value; }
        }
        #endregion
        public CompressFilter() { }
        public CompressFilter(bool isAvailable)
        {
            _isavailable = isAvailable;
        }
        public override void OnActionExecuting(ActionExecutingContext filterContext)
        {
            if (!IsAvailable)
            {
                base.OnActionExecuting(filterContext);
                return;
            }
            if (filterContext.HttpContext.IsCustomErrorEnabled)
            {
                HttpRequestBase request = filterContext.HttpContext.Request;
                string acceptEncoding = request.Headers["Accept-Encoding"];
                if (string.IsNullOrEmpty(acceptEncoding)) return;
                acceptEncoding = acceptEncoding.ToUpperInvariant();
                HttpResponseBase response = filterContext.HttpContext.Response;
                if (acceptEncoding.Contains("GZIP"))
                {
                    response.AppendHeader("Content-encoding", "gzip");
                    response.Filter = new GZipStream(response.Filter, CompressionMode.Compress);
                }
                else if (acceptEncoding.Contains("DEFLATE"))
                {
                    response.AppendHeader("Content-encoding", "deflate");
                    response.Filter = new DeflateStream(response.Filter, CompressionMode.Compress);
                }
            }
        }
    }

配合HtmlFilter 使用，其乐无穷～！