c# - What is the correct way to access a remote resource in my MVC controller? -

i using mvc 5 on .net , have user flow looks this:

1. user enters address form.
2. form gets posted controller using ajax.
3. controller records address database.
4. controller makes webclient request bing maps geocode address latitude , longitude.
5. controller records latitude , longitude database.
6. controller returns ajax result rendered client-side updated view address , latitude/longitude.

i know call bing maps should happen in async context site's speed uncoupled of bing maps.

instead think flow should work this:

1. user enters address form.
2. form gets posted controller using ajax.
3. controller records address database.
4. controller launches async task geocoding , update database
5. controller returns ajax result client shows updated address , tells poll client-side completion of geocode result.

i stuck on step #4. here have:

public actionresult getlocation(int id) {     listing li = db.listings.find(id);      task.run(() => {         // update geocode if necessary         if (li.bizaddress.geostatus != businessaddress.geocodestatus.uptodate &&             datetime.now - li.bizaddress.lastgeoattempt > timespan.fromhours(1))         {             geocoder geo = new geocoder();             geocoderesult gr = geo.geocode(li.bizaddress).result;             if (gr.badresult != true)             {                 li.bizaddress.latitude = gr.location.latitude;                 li.bizaddress.longitude = gr.location.longitude;                 li.bizaddress.geostatus = businessaddress.geocodestatus.uptodate;              }             else             {                 // failed                 li.bizaddress.latitude = 0;                 li.bizaddress.longitude = 0;                 li.bizaddress.geostatus = businessaddress.geocodestatus.badresult;             }              li.bizaddress.lastgeoattempt = datetime.now;             db.savechanges();         }      });       return partialview("~/views/listing/listingpartials/_location.cshtml", li); } 

however exception db context has been disposed of when db.savechanges().

i want task run async inside of closure db still valid undisposed variable.

is possible? i'm new async programming , don't know of idioms yet.

additional info: rendering panel in view this:

@{html.action("getlocation", new { id = model.id });} 

i want keep behavior since loading ajax may hurt seo.

firing off task in way not practice. instead, mark actionresult signature async , await results need inside method body. way won't tying server resources waiting response bing. frees having worry instructing client side poll future result consider anti-pattern in async programming. it's easier deal in 1 call , send result when it's available. since you're using ef6 can leverage async methods improve server performance.

public async task<actionresult> getlocation(int id) {     var listing = await db.listings.findasync(id);     ...     var gr = await geo.geocode(li.bizaddress); 

at least, if you're sure want go down path important clean task code. it's bad practice use .result tasks inside of web server locks server threads. change definition of task async:

task.run(async () => {         // update geocode if necessary         if (li.bizaddress.geostatus != businessaddress.geocodestatus.uptodate &&             datetime.now - li.bizaddress.lastgeoattempt > timespan.fromhours(1))         {             geocoder geo = new geocoder();             geocoderesult gr = await geo.geocode(li.bizaddress);