How to use Generic Handlers (ASHX) in ASP.NET MVC?

Question

I need a image generator in my ASP.NET MVC application, but I don't know if it is possible to use ASHX in ASP.NET MVC.

If there is an class similar to IHttpHandler that inherits IViewDataContainer, then I could use ViewData.Model on my ASHX.

I read a blog post about it but it seem outdated from the info I got in the ASP.NET forum

Any ideas?

Answer 1

You should just be able to return the image from the action? See here for more.

And yes, you can use ashx alongside MVC (by telling it to ignore the route) - but I'm not sure that is the best approach unless it is to re-use existing code.

---

Sorry guys, the link has been removed. It happens.

Answer 2

You can also use this ImageResult class to return an image.

No need for a handler just create a route such as:

/ImageGenerator/{action}/{imageid}/

and return an ImageResult for the request.

 public class ImageResult : ActionResult
    {
        public string SourceFilename { get; set; }
        public MemoryStream SourceStream { get; set; }
        public string ContentType { get; set; }
        public ImageResult(string sourceFilename)
        {
            SourceFilename = sourceFilename;
            ContentType = FileTypeHelper.GetContentType(SourceFilename);
        }
        public ImageResult(MemoryStream sourceStream, string contentType)
        {
            SourceStream = sourceStream;
            ContentType = contentType;
        }
        public override void ExecuteResult(ControllerContext context)
        {   
            var res = context.HttpContext.Response;
            res.Clear();
            res.Cache.SetCacheability(HttpCacheability.NoCache);
            res.ContentType = ContentType;

            if (SourceStream != null)
            {
                SourceStream.WriteTo(res.OutputStream);

            }
            else
            {
               res.TransmitFile(SourceFilename);
            }

        }


    }

To use this do the following in a controller and add a route for it:

public ImageResult GetImage(int imageId)
{
   // Database fetch of image details
   var imageInfo = repository.Get<ImageInfo>(imageId);
   return new ImageResult(imageInfo.FullFilename);
}

Have added the FileType helper class too:

 public static class FileTypeHelper
{
    public static string GetContentType(string SourceFileName)
    {
        var extension = Path.GetExtension(SourceFileName).ToLower();
         switch (extension)
        {
            case ".ai": return "application/postscript";
            case ".aif": return "audio/x-aiff";
            case ".aifc": return "audio/x-aiff";
            case ".aiff": return "audio/x-aiff";
            case ".asc": return "text/plain";
            case ".au": return "audio/basic";
            case ".avi": return "video/x-msvideo";
            case ".bcpio": return "application/x-bcpio";
            case ".bin": return "application/octet-stream";
            case ".c": return "text/plain";
            case ".cc": return "text/plain";
            case ".ccad": return "application/clariscad";
            case ".cdf": return "application/x-netcdf";
            case ".class": return "application/octet-stream";
            case ".cpio": return "application/x-cpio";
            case ".cpp": return "text/plain";
            case ".cpt": return "application/mac-compactpro";
            case ".cs": return "text/plain";
            case ".csh": return "application/x-csh";
            case ".css": return "text/css";
            case ".dcr": return "application/x-director";
            case ".dir": return "application/x-director";
            case ".dms": return "application/octet-stream";
            case ".doc": return "application/msword";
            case ".drw": return "application/drafting";
            case ".dvi": return "application/x-dvi";
            case ".dwg": return "application/acad";
            case ".dxf": return "application/dxf";
            case ".dxr": return "application/x-director";
            case ".eps": return "application/postscript";
            case ".etx": return "text/x-setext";
            case ".exe": return "application/octet-stream";
            case ".ez": return "application/andrew-inset";
            case ".f": return "text/plain";
            case ".f90": return "text/plain";
            case ".fli": return "video/x-fli";
            case ".flv": return "video/x-flv";
            case ".gif": return "image/gif";
            case ".gtar": return "application/x-gtar";
            case ".gz": return "application/x-gzip";
            case ".h": return "text/plain";
            case ".hdf": return "application/x-hdf";
            case ".hh": return "text/plain";
            case ".hqx": return "application/mac-binhex40";
            case ".htm": return "text/html";
            case ".html": return "text/html";
            case ".ice": return "x-conference/x-cooltalk";
            case ".ief": return "image/ief";
            case ".iges": return "model/iges";
            case ".igs": return "model/iges";
            case ".ips": return "application/x-ipscript";
            case ".ipx": return "application/x-ipix";
            case ".jpe": return "image/jpeg";
            case ".jpeg": return "image/jpeg";
            case ".jpg": return "image/jpeg";
            case ".js": return "application/x-javascript";
            case ".kar": return "audio/midi";
            case ".latex": return "application/x-latex";
            case ".lha": return "application/octet-stream";
            case ".lsp": return "application/x-lisp";
            case ".lzh": return "application/octet-stream";
            case ".m": return "text/plain";
            case ".man": return "application/x-troff-man";
            case ".me": return "application/x-troff-me";
            case ".mesh": return "model/mesh";
            case ".mid": return "audio/midi";
            case ".midi": return "audio/midi";
            case ".mime": return "www/mime";
            case ".mov": return "video/quicktime";
            case ".movie": return "video/x-sgi-movie";
            case ".mp2": return "audio/mpeg";
            case ".mp3": return "audio/mpeg";
            case ".mpe": return "video/mpeg";
            case ".mpeg": return "video/mpeg";
            case ".mpg": return "video/mpeg";
            case ".mpga": return "audio/mpeg";
            case ".ms": return "application/x-troff-ms";
            case ".msh": return "model/mesh";
            case ".nc": return "application/x-netcdf";
            case ".oda": return "application/oda";
            case ".pbm": return "image/x-portable-bitmap";
            case ".pdb": return "chemical/x-pdb";
            case ".pdf": return "application/pdf";
            case ".pgm": return "image/x-portable-graymap";
            case ".pgn": return "application/x-chess-pgn";
            case ".png": return "image/png";
            case ".pnm": return "image/x-portable-anymap";
            case ".pot": return "application/mspowerpoint";
            case ".ppm": return "image/x-portable-pixmap";
            case ".pps": return "application/mspowerpoint";
            case ".ppt": return "application/mspowerpoint";
            case ".ppz": return "application/mspowerpoint";
            case ".pre": return "application/x-freelance";
            case ".prt": return "application/pro_eng";
            case ".ps": return "application/postscript";
            case ".qt": return "video/quicktime";
            case ".ra": return "audio/x-realaudio";
            case ".ram": return "audio/x-pn-realaudio";
            case ".ras": return "image/cmu-raster";
            case ".rgb": return "image/x-rgb";
            case ".rm": return "audio/x-pn-realaudio";
            case ".roff": return "application/x-troff";
            case ".rpm": return "audio/x-pn-realaudio-plugin";
            case ".rtf": return "text/rtf";
            case ".rtx": return "text/richtext";
            case ".scm": return "application/x-lotusscreencam";
            case ".set": return "application/set";
            case ".sgm": return "text/sgml";
            case ".sgml": return "text/sgml";
            case ".sh": return "application/x-sh";
            case ".shar": return "application/x-shar";
            case ".silo": return "model/mesh";
            case ".sit": return "application/x-stuffit";
            case ".skd": return "application/x-koan";
            case ".skm": return "application/x-koan";
            case ".skp": return "application/x-koan";
            case ".skt": return "application/x-koan";
            case ".smi": return "application/smil";
            case ".smil": return "application/smil";
            case ".snd": return "audio/basic";
            case ".sol": return "application/solids";
            case ".spl": return "application/x-futuresplash";
            case ".src": return "application/x-wais-source";
            case ".step": return "application/STEP";
            case ".stl": return "application/SLA";
            case ".stp": return "application/STEP";
            case ".sv4cpio": return "application/x-sv4cpio";
            case ".sv4crc": return "application/x-sv4crc";
            case ".swf": return "application/x-shockwave-flash";
            case ".t": return "application/x-troff";
            case ".tar": return "application/x-tar";
            case ".tcl": return "application/x-tcl";
            case ".tex": return "application/x-tex";
            case ".tif": return "image/tiff";
            case ".tiff": return "image/tiff";
            case ".tr": return "application/x-troff";
            case ".tsi": return "audio/TSP-audio";
            case ".tsp": return "application/dsptype";
            case ".tsv": return "text/tab-separated-values";
            case ".txt": return "text/plain";
            case ".unv": return "application/i-deas";
            case ".ustar": return "application/x-ustar";
            case ".vcd": return "application/x-cdlink";
            case ".vda": return "application/vda";
            case ".vrml": return "model/vrml";
            case ".wav": return "audio/x-wav";
            case ".wrl": return "model/vrml";
            case ".xbm": return "image/x-xbitmap";
            case ".xlc": return "application/vnd.ms-excel";
            case ".xll": return "application/vnd.ms-excel";
            case ".xlm": return "application/vnd.ms-excel";
            case ".xls": return "application/vnd.ms-excel";
            case ".xlw": return "application/vnd.ms-excel";
            case ".xml": return "text/xml";
            case ".xpm": return "image/x-xpixmap";
            case ".xwd": return "image/x-xwindowdump";
            case ".xyz": return "chemical/x-pdb";
            case ".zip": return "application/zip";
            default: return string.Format("application/{0}", extension);
        }
    }
}