topic Re: IActiveView.Output times out in ArcObjects SDK Questions

IActiveView.Output times out

BjørnarSundsbø — Thu, 14 Oct 2010 10:23:44 GMT

I use IMapDocument and its ActiveView.Output to export a bitmap from an MXD documen to a bitmap. This works just fine with an MXD with local data. However, when exporting from an MXD connected to an ArcGIS Server Map Service, the output method seems to time out, and nothing is exported to the bitmap.

Looking at the jobs folder on the arcgisserver, I can see new cache images are crated for the extent I exported. If I zoom out one level, and back in, I get the map image. So in other words I have to export to every extent twice to get an exported map.

What is the reason for this? Is there a timeout setting I have yet to find? The code for exporting is pretty much what you see on different threads here. I do not believe it is the actual code used to export which is the problem.

I use ArcObjects 9.3. I've seen in version 10 there is an ITrackCancel2 interface which has a Timeout property, which might be something I'm looking for. But I hope there is a different way of allowing the Output to wait a bit longer for result from the MapServer service.

Re: IActiveView.Output times out

OttarViken_Valvåg — Fri, 15 Oct 2010 09:38:22 GMT

Hi Bjørnar, it would be easier to comment if you did show us your code, even if it's copied from a sample.

Re: IActiveView.Output times out

BjørnarSundsbø — Fri, 10 Dec 2021 21:55:07 GMT

If I call the following method twice, it works, but exporting the same image twice every time i need an image is not an option. Most of the time i will be using an MXD pointing to local data, and doubling the already long export time is not exactly ideal.

private Bitmap GetImageFromJpegExporter(tagRECT rect, CancelTracker trackCancel)
        {
            string filename = Guid.NewGuid().ToString();
            try
            {
                tagRECT exportRECT = _mapDocument.ActiveView.ExportFrame;

                //Create a new envelope object and populate it with the values from exportRECT.
                // We need to do this because the exporter object requires an envelope object
                // instead of a tagRECT structure.
                IEnvelope pPixelBoundsEnv = new EnvelopeClass();
                pPixelBoundsEnv.PutCoords(exportRECT.left, exportRECT.top, exportRECT.right, exportRECT.bottom);

                IExport export = new ExportJPEGClass
                {
                    Resolution = 96,
                    ExportFileName = filename,
                    PixelBounds = pPixelBoundsEnv
                };

                Stopwatch watch = new Stopwatch();
                watch.Start();
                int hwnd = export.StartExporting();
                _mapDocument.ActiveView.Output(hwnd, 96, ref rect, _mapDocument.ActiveView.Extent, trackCancel);
                export.FinishExporting();
                export.Cleanup();
                watch.Stop();
                Trace.WriteLine("Export took " + watch.ElapsedMilliseconds + " ms");
                Bitmap fromFileBitmap = new Bitmap(filename);
                // Copy fromFileBitmap because it keeps a lock on the file 
                Bitmap returnBitmap = new Bitmap(fromFileBitmap);
                fromFileBitmap.Dispose();
                return returnBitmap;
            }
            finally
            {
                if(File.Exists(filename))
                {
                    try
                    {
                        File.Delete(filename);
                    }
                    catch (Exception)
                    {
                        
                    }
                }
            }

        }

Re: IActiveView.Output times out

OttarViken_Valvåg — Fri, 15 Oct 2010 10:22:02 GMT

Is your mxd using an internet connection or a local connection to the AGS map service? You could test whether or not this makes a difference.

If exporting twice is what it takes to make things work, a workaround might be to cancel the first export operation after one second and then redoing the export.

Re: IActiveView.Output times out

BjørnarSundsbø — Fri, 15 Oct 2010 10:38:47 GMT

I use a local connection to the mapservice. Canceling the operation after a little while is just as bad as exporting twice in my book. The second call will never be necessary if the data is local (fgdb), as the map image will be available in the first export.

I've been looking through the interfaces used by MapDocument to see if I can find a way to set any settings in case a mapservice/wms layer is in use, but no luck so far. There has to be some way to tell the map that we want to change settings on how it interacts with a remote source?

Re: IActiveView.Output times out

OttarViken_Valvåg — Fri, 15 Oct 2010 11:07:25 GMT

You can just loop through your layers and see which interfaces they implement. ArcGIS Server Map Services should be contained in IMapServerSublayer interfaces, and WMS layers should be IWMSLayer interfaces.

http://help.arcgis.com/en/sdk/10.0/arcobjects_net/componenthelp/index.html#/IMapServerSublayer_Interface/001200000m2p000000/

http://help.arcgis.com/en/sdk/10.0/arcobjects_net/componenthelp/index.html#/IWMSMapLayer_Interface/001200000rwt000000/

Re: IActiveView.Output times out

BjørnarSundsbø — Fri, 15 Oct 2010 11:54:16 GMT

Checking for those interfaces to determine if I should export the map once or twice does work. However, I feel this is a hack in the programming-by-coincidence category. Who's to say this is not an issue on a different ArcGIS server installation, or that on the next, I need to export three times because of some other delay?

Any further information on how to fix what is going wrong here would be highly appreciated.

Bjørnar

Re: IActiveView.Output times out

OttarViken_Valvåg — Fri, 15 Oct 2010 11:56:53 GMT

Did you try to change your connection to ArcGIS Server to an internet connection?

Re: IActiveView.Output times out

BjørnarSundsbø — Fri, 15 Oct 2010 12:12:17 GMT

No. Our server is not exposed to the internet, and the GIS guy left for the weekend and I have no ArcMap on a machine available to me

Re: IActiveView.Output times out

BjørnarSundsbø — Mon, 18 Oct 2010 08:31:54 GMT

I changed the Output type of the service to MIME only instead of MIME + URL, and that did the trick. I get the image on the first attempt. What kind of consequences will this have on performance? From what I can see, the images generated to the argcisoutput directory has a very limited time of life, so the will not really serve as a proper cache.

Re: IActiveView.Output times out

OttarViken_Valvåg — Thu, 21 Oct 2010 08:06:16 GMT

When using MIME access, the output image is stored as a .tmp file in the output directory, streamed to the client, and then deleted. When using url access, the output image is stored as an image file in the output directory, its url is returned to the client, and the image will reside in the output directory for 10 minutes. So the output directory never serves as a cache, it's just a means for returning dynamically generated images to the client.

Using MIME access instead of URL access has no negative impact on performance.

Re: IActiveView.Output times out

BjørnarSundsbø — Thu, 21 Oct 2010 08:20:03 GMT

Thanks, Ottar.

Any luck/time finding out what is really going on, and why it doesn't work when using MIME + URL?

Also, we have pretty much the same problem when using a WMS layer in the mxd used by the client. We get the map image, but WMS layer is absent from the image.

Bjørnar

Re: IActiveView.Output times out

OttarViken_Valvåg — Thu, 21 Oct 2010 10:03:20 GMT

It sounds like ArcMap / ArcEngine is having problems downloading the generated image. Check that the output directory of your ArcGIS Server has a virtual path that is accessible to your client. Also maybe check to see if your client is using a proxy server for outgoing internet connections?

Re: IActiveView.Output times out

BjørnarSundsbø — Thu, 21 Oct 2010 10:06:44 GMT

No issues with proxy. I checked the virtual path setup, and tested it. So did Toni, so it seems to be working as it should. I think the WMS issue is the most pressing matter at the moment.

Re: IActiveView.Output times out

BjørnarSundsbø — Wed, 27 Oct 2010 11:27:21 GMT

I just noticed something interesting; when having an MXD with a reference to a WMS layer, the export operation returns an empty image. However, a PNG for the requested area is created in the temp folder for my user. The output method fails in other words to draw that layer onto the hdc passed into the Output method.

The case is the same with the ArcGIS Map Server request where I get an empty image the first time I export an image, and get it the next time. This was, as described in an earlier post, resolved by changing from MIME + URL to MIME for output type for the service. This temp file is also created when output is MIME only.

Why is the Output method not rendering the WMS and ArcGIS Map layers to the hdc when it is obviously retrieving the image and should be able to do so?

Bjørnar