topic Re: Check if map service is running or not from Silverlight API in ArcGIS API for Silverlight Questions

Check if map service is running or not from Silverlight API

JaskiratAnand — Mon, 18 Apr 2011 09:55:45 GMT

Hi,

can I some how check if my map service is running or not before loading my map control. If teh map service is down and the user runs the application I get the following stack trace:
at ESRI.ArcGIS.Client.ArcGISDynamicMapServiceLayer.MapServiceInfoInitialized(Object sender, MapServiceInitalizeArgs args)
   at ESRI.ArcGIS.Client.Services.MapService.OnInitialized(MapServiceInitalizeArgs args)
   at ESRI.ArcGIS.Client.Services.MapService.wc_DownloadStringCompleted(Object sender, DownloadStringCompletedEventArgs e)
   at System.Net.WebClient.OnDownloadStringCompleted(DownloadStringCompletedEventArgs e)
   at System.Net.WebClient.DownloadStringOperationCompleted(Object arg)
and the following error message:
Object reference not set to an instance of an object

Any help on the same is will be very useful.
Thanks

Re: Check if map service is running or not from Silverlight API

TerryGiles — Sat, 11 Dec 2021 13:07:48 GMT

Add a handler for the InitializationFailed event on each layer in your map.

XAML

            <esri:Map x:Name="MyMap" >
                <esri:ArcGISDynamicMapServiceLayer ID="MyLayer"
                Url="http://sampleserver1.arcgisonline.com/ArcGIS/rest/services/Specialty/ESRI_StateCityHighway_USA/MapServer"
                InitializationFailed="DynLayer_InitializationFailed"/>
            </esri:Map>

        void DynLayer_InitializationFailed(object sender, EventArgs e)
        {
            Layer lyr = sender as Layer;
            MyMap.Layers.Remove(lyr);

        }

I know this does not really answer the question as to checking if the service is running or not but should prevent the error and will remove the broken layer from the map.

Re: Check if map service is running or not from Silverlight API

ChristopherHill — Mon, 18 Apr 2011 15:21:30 GMT

You would have to do a web request to the server and check that you didn't get a 404 or some other error.

Re: Check if map service is running or not from Silverlight API

JaskiratAnand — Thu, 21 Apr 2011 11:00:20 GMT

do a web request to the server

do you mean that i should try and access the server using soap.

Re: Check if map service is running or not from Silverlight API

JaskiratAnand — Sat, 11 Dec 2021 13:07:50 GMT

Add a handler for the InitializationFailed event on each layer in your map.

XAML

            <esri:Map x:Name="MyMap" >
                <esri:ArcGISDynamicMapServiceLayer ID="MyLayer"
                Url="http://sampleserver1.arcgisonline.com/ArcGIS/rest/services/Specialty/ESRI_StateCityHighway_USA/MapServer"
                InitializationFailed="DynLayer_InitializationFailed"/>
            </esri:Map>

        void DynLayer_InitializationFailed(object sender, EventArgs e)
        {
            Layer lyr = sender as Layer;
            MyMap.Layers.Remove(lyr);

        }

I know this does not really answer the question as to checking if the service is running or not but should prevent the error and will remove the broken layer from the map.

have already done that but the point is that if your service is down the layer initialization won't even begin, the exception will happen while map service initialization, which is what I'm trying to capture.

Re: Check if map service is running or not from Silverlight API

TerryGiles — Sat, 11 Dec 2021 13:07:53 GMT

I just stopped all the map services used in my application and I do not get any errors. Can you post the code that is throwing the error and in what event handler? I stubbed in a Initialized handler for my dynamic layers and it executes even though the underlying service is not there.

        void DynLayer_Initialized(object sender, EventArgs e)
        {
            ArcGISDynamicMapServiceLayer dlyr = sender as ArcGISDynamicMapServiceLayer;

            if (dlyr.Layers == null)
            {
                return;
            }
        }

Re: Check if map service is running or not from Silverlight API

VickyP — Wed, 16 Nov 2011 05:25:35 GMT

have already done that but the point is that if your service is down the layer initialization won't even begin, the exception will happen while map service initialization, which is what I'm trying to capture.

Hi Jaskirat Anand,

   Did you found any solution for Checking if map service is running or not from Silverlight API? If yes then please share with me, I also tried using InitializationFailed and Initialized event of ArcGISDynamicMapServiceLayer, I am also stopping the MapService but it is not showing dlyr.Layers == null
ArcGISDynamicMapServiceLayer dlyr = sender as ArcGISDynamicMapServiceLayer;

            if (dlyr.Layers == null)
            {
                return;
            }

dlyr.Layers is still having values of the layers in the mapservice.

Thanks & Regards,
Varun