topic Re: Arcgis Online Geocoding service in .NET Maps SDK Questions

Arcgis Online Geocoding service

MaheshReddy — Thu, 03 Sep 2015 07:49:08 GMT

Hi All,

I am looking for an online web service to get Lat, Long values for the addresses using Arcgis Online Geocoding service. Please let me know if there is any dll or online web service to get the results using .Net Framework 4.0 and Visual Studio 2010.

Thank you,

Mahesh

Re: Arcgis Online Geocoding service

AnttiKajanus1 — Thu, 03 Sep 2015 08:12:31 GMT

You can use ArcGIS Runtime for .NET to access the Geocoding service but it needs 4.5 framework to work. If you have to stay on 4.0 framework, you could have a look our older ArcGIS Runtime for WPF SDK. It support using locators too.

Re: Arcgis Online Geocoding service

MaheshReddy — Thu, 03 Sep 2015 08:29:20 GMT

Thanks for your reply.

While going through documentation, I found this link: http://geocode.arcgis.com/arcgis/rest/services/World/GeocodeServer/findAddressCandidates to get lat, long from the address provided. Can I use this link from .Net code?

If so, do I need to create a .Net wrapper for authentication and get token to get the results?

Yes, we have to use .Net framework 4.0 only. Is dll mandatory for using Geocoding service? Please let me know if there is any alternative way like using web services.

Thank you,

Mahesh

Re: Arcgis Online Geocoding service

AnttiKajanus1 — Thu, 03 Sep 2015 08:35:51 GMT

One option is to write the task logic by hand and access the rest endpoint from your own code. We provide existing tasks in our SDK's to communicate with the service but in some cases rolling your own implementation might be an option.

If you want to go that route, please refer ArcGIS REST API: World Geocoding Service documentation for rest spec and authentication details.

Re: Arcgis Online Geocoding service

MaheshReddy — Thu, 03 Sep 2015 08:55:09 GMT

ArcGIS REST API should be good for my development purposes. As mentioned, I found following links: http://geocode.arcgis.com/arcgis/rest/services/World/GeocodeServer/findAddressCandidates?<PARAMETERS> and https://www.arcgis.com/sharing/oauth2/token?client_id=<YOUR CLIENT ID>&grant_type=client_credentials&client_secret=<YOUR CLIENT SECRET>&f=pjson for authentication and generating token.

Can you help me out with a sample .Net code to generate token? Thanks for your help.

Re: Arcgis Online Geocoding service

AnttiKajanus1 — Thu, 03 Sep 2015 09:11:36 GMT

We also provide out-of-the-box implementations for authentication in the SDK's but for more details how to implement it, please refer authentication documentation. What comes to c# implementation, you might want to check if there are 3rd party libraries that provides implementation for OAUTH 2.0.

Re: Arcgis Online Geocoding service

MaheshReddy — Fri, 04 Sep 2015 03:45:19 GMT

I am using following url to get lat, long: http://geocode.arcgis.com/arcgis/rest/services/World/GeocodeServer/findAddressCandidates?Address=Starbucks&Neighborhood=&City=Tanjong Pagar&Subregion=&Region=&CountryCode=SGP&outFields=Addr_type&maxLocations=1&forStorage=false&f=pjson and able to get the results, when Address is provided along with Country.

But for some addresses, require Lat, Long for Country only. However, when I just input country code, the result is not correct. For eg.,

http://geocode.arcgis.com/arcgis/rest/services/World/GeocodeServer/findAddressCandidates?Address=&Neighborhood=&City=&Subregion=&Region=&CountryCode=SGP&outFields=Addr_type&maxLocations=1&forStorage=false&f=pjson. Is there a way, we can get center of the Country geocodes?

Thank you.

Re: Arcgis Online Geocoding service

ThadTilton — Fri, 04 Sep 2015 19:26:53 GMT

I haven't had success either in getting a consistent geocode result using just a country code ("USA" seems to work, others do not).

There's an example on the developers.arcgis.com site that does this successfully (https://developers.arcgis.com/en/features/geocoding/), but uses a combination of "suggest" (to get the desired country) and "find" (to retrieve the result).

One option is to simply query a country boundary service for the geometry and find the center (of the extent, e.g.). For example:

var queryUrl = "http://services.arcgis.com/P3ePLMYs2RVChkJx/arcgis/rest/services/World_Countries_(Generalized)/FeatureServer/0";

var queryTask = new QueryTask(new Uri(queryUrl));

var queryExp = "ISO = '" + this.CountryTextBox.Text + "'"; // SG, US, DK, for example (two-letter codes)

// var queryExp = "Country ='" + this.CountryTextBox.Text + "'"; // Singapore, United States, Denmark, for example

var countryQuery = new Query(queryExp);

var result = await queryTask.ExecuteAsync(countryQuery);

if (result.FeatureSet.Features.Count > 0)

{

var countryExtent = result.FeatureSet.Features[0].Geometry.Extent as Envelope;

var countryCenter = countryExtent.GetCenter();

await this.MyMapView.SetViewAsync(countryCenter);

MessageBox.Show("Center of '" +

this.CountryTextBox.Text + "' is " +

countryCenter.X.ToString() + " : " +

countryCenter.Y.ToString());

}

else

{

MessageBox.Show("No results found for '" + this.CountryTextBox.Text + "'.");

}

Re: Arcgis Online Geocoding service

dotMorten_esri — Fri, 04 Sep 2015 23:47:20 GMT

I know this is slightly off topic, but would just like to point out that .NET 4.0 is losing support on January 12, 2016:

https://support.microsoft.com/en-us/lifecycle?sort=pn&alpha=.net%20framework

So you only have a few months left before you have to upgrade anyway.

Re: Arcgis Online Geocoding service

MaheshReddy — Mon, 07 Sep 2015 02:32:45 GMT

Thanks for your reply. Due to some issues, I cannot use ArcGIS runtime dll. Is there any rest url to get the results with countryCode.

Thanks in advance.

Re: Arcgis Online Geocoding service

MaheshReddy — Mon, 07 Sep 2015 02:43:20 GMT

Thanks for the information. We are in the process of upgrading the framework.

Re: Arcgis Online Geocoding service

DEWright_CA — Mon, 07 Sep 2015 02:55:09 GMT

Ok, so you want the Lat/Long for the addresses you geocode? These attributes are exposed by either the REST or SOAP interfaces.

Or are you just wanting to Reverse Geocode the locations against that ArcGIS Online locator?

Re: Arcgis Online Geocoding service

MaheshReddy — Mon, 07 Sep 2015 03:14:36 GMT

I want the Lat/Long for the addresses provided. I tried with the REST service and able to get the Lat/Long, but when countryCode alone is passed, I could not get the correct results.

Thad Tilton provided me code snippet, but I am looking for REST/SOAP url to get the correct results when only countryCode is passed.

Please check below:

I am using following url to get lat, long:http://geocode.arcgis.com/arcgis/rest/services/World/GeocodeServer/findAddressCandidates?Address=Starbucks&Neighborhood=&City=TanjongPagar&Subregion=&Region=&CountryCode=SGP&outFields=Addr_type&maxLocations=1&forStorage=false&f=pjson and able to get the results, when Address is provided along with Country.

But for some addresses, require Lat, Long for Country only. However, when I just input country code, the result is not correct. For eg.,

Thank you.

Re: Arcgis Online Geocoding service

DEWright_CA — Mon, 07 Sep 2015 03:37:54 GMT

Using only a country code does not meet the needed minimums for a full reverse-geocode for all locations. The more information you include the more precise a result you get. When you pass in only a country code, you will get the center of mass for the polygon for that country.

Re: Arcgis Online Geocoding service

MaheshReddy — Mon, 07 Sep 2015 06:20:45 GMT

We pass as much information as we have to get the lat/long for the addresses. For some addresses, we have only CountryCode without any other information. We should be able to get Lat/Long from the countryCode provided.

Is there a way we can get lat/long from location or extent below:

"candidates": [

{

"address": "Sgp",

"location": {

"x": -40.309738060999621,

"y": -20.310026429999596

"score": 100,

"attributes": {

"Addr_type": "POI"

"extent": {

"xmin": -40.314739000000003,

"ymin": -20.315027000000001,

"xmax": -40.304738999999998,

"ymax": -20.305026999999999

}

]

Re: Arcgis Online Geocoding service

dotMorten_esri — Tue, 08 Sep 2015 19:17:44 GMT

When you only have very little information, geocoding gets more inaccurate. If you increase the maxLocations value to return a few more than one result, it seems to me the second result is the correct one (also achieves a score of 100):

http://geocode.arcgis.com/arcgis/rest/services/World/GeocodeServer/findAddressCandidates?CountryCode=SGP&outFields=Addr_type&maxLocations=10&f=pjson

Blindly geocoding to the first result without human verification can be a little dangerous. Often it's better to ask for a few locations, and present the user with multiple options during the geocoding process - especially if you get more than one result with a confidence score close to a 100.

Re: Arcgis Online Geocoding service

DEWright_CA — Tue, 08 Sep 2015 23:02:22 GMT

To me; its looks like you need to put in your code minimum requirements to process so you don't spend time trying to massage data that is already going to be highly inaccurate it not problematic.

At the least a street address and jurisdiction name, or a address and postal-code; as you look at the various numbers of fields you can use then you can adjust according.