Asp.Net MVC 页面代码压缩筛选器-自定义删除无效内容

Asp.Net MVC 页面代码压缩筛选器

首先定义以下筛选器，用于代码压缩。

/*页面压缩 筛选器*/
    public class WhiteSpaceFilter : Stream
    {
        private Stream _shrink;
        private Func<string, string> _filter;

        public WhiteSpaceFilter(Stream shrink, Func<string, string> filter)
        {
            _shrink = shrink;
            _filter = filter;
        }


        public override bool CanRead { get { return true; } }
        public override bool CanSeek { get { return true; } }
        public override bool CanWrite { get { return true; } }
        public override void Flush() { _shrink.Flush(); }
        public override long Length { get { return 0; } }
        public override long Position { get; set; }
        public override int Read(byte[] buffer, int offset, int count)
        {
            return _shrink.Read(buffer, offset, count);
        }
        public override long Seek(long offset, SeekOrigin origin)
        {
            return _shrink.Seek(offset, origin);
        }
        public override void SetLength(long value)
        {
            _shrink.SetLength(value);
        }
        public override void Close()
        {
            _shrink.Close();
        }

        public override void Write(byte[] buffer, int offset, int count)
        {
            // capture the data and convert to string
            byte[] data = new byte[count];
            Buffer.BlockCopy(buffer, offset, data, 0, count);
            string s = Encoding.GetEncoding("gb2312").GetString(buffer);

            // filter the string
            s = _filter(s);

            // write the data to stream
            byte[] outdata = Encoding.GetEncoding("gb2312").GetBytes(s);
            _shrink.Write(outdata, 0, outdata.GetLength(0));
        }
    }

    public class WhitespaceFilterAttribute : ActionFilterAttribute
    {
        public override void OnActionExecuting(ActionExecutingContext filterContext)
        {
            var request = filterContext.HttpContext.Request;
            var response = filterContext.HttpContext.Response;
            response.Filter = new WhiteSpaceFilter(response.Filter, s =>
            {
                s = Regex.Replace(s, @"\s+(?=<)|\s+$|(?<=>)\s+|<!--.+-->|[ ]+//.+\n|/\*.+\*/|\n", "");

                //single-line doctype must be preserved
                var firstEndBracketPosition = s.IndexOf(">");
                if (firstEndBracketPosition >= 0)
                {
                    s = s.Remove(firstEndBracketPosition, 1);
                    s = s.Insert(firstEndBracketPosition, ">");
                }
                return s;
            });
        }
    }
    /*页面压缩 筛选器 end*/

在要压缩页面的action上使用。

[WhitespaceFilter]
public ActionResult home()
{
      return View();
}

我们可以自行修改替换规则,以达到最优化。

s = Regex.Replace(s, @"\s+(?=<)|\s+$|(?<=>)\s+|<!--.+-->|[ ]+//.+\n|/\*.+\*/|\n", "");