c# - How can I make my json query wait for phone's location? -

here trying send json query latitude , longitude these values going nan though call showmylocationonthemap retrieves phone location first. how can make showmylocation method finish first , call json query. can me out?

public partial class closestbusstops : phoneapplicationpage {     webclient webclient;     public closestbusstops()     {         initializecomponent();         showmylocationonthemap(geopositionaccuracy.default);         webclient = new webclient();         webclient.downloadstringcompleted += webclient_downloadstringcompleted;         string jsonquery= "www.blabla.com?lat="+app.lat+"&lng="+app.lng;         webclient.downloadstringasync(new uri(jsonquery));     }      private async void showmylocationonthemap(geopositionaccuracy accuracy)     {         geolocator mygeolocator = new geolocator();         geoposition mygeoposition = await mygeolocator.getgeopositionasync();         geocoordinate mygeocoordinate = mygeoposition.coordinate;         geocoordinate mygeocoordinate = coordinateconverter.convertgeocoordinate(mygeocoordinate);          app.lat = mygeocoordinate.latitude;         app.lng = mygeocoordinate.longitude;          this.pushpin(this.mapwithmylocation, mygeocoordinate);      } } 

updated

protected override void onnavigatedto(system.windows.navigation.navigationeventargs e)         {              await showmylocationonthemap(geopositionaccuracy.default); }  private async task showmylocationonthemap(geopositionaccuracy accuracy)         {             geolocator mygeolocator = new geolocator();             geoposition mygeoposition = await mygeolocator.getgeopositionasync();             geocoordinate mygeocoordinate = mygeoposition.coordinate;             geocoordinate mygeocoordinate = coordinateconverter.convertgeocoordinate(mygeocoordinate);              app.lat = mygeocoordinate.latitude;             app.lng = mygeocoordinate.longitude;              this.pushpin(this.mapwithmylocation, mygeocoordinate);         } 

showmylocationonthemap async method, if want wait completion of method, need use await keyword, this:

await showmylocationonthemap(geopositionaccuracy.default); 

since cannot use await in constructor, need move somewhere else, onnavigatedto method or loaded event handler.

also return type of showmylocationonthemap should task instead of void.

update:

    public closestbusstops()     {         initializecomponent();     }      private async task showmylocationonthemap(geopositionaccuracy accuracy)     {         geolocator mygeolocator = new geolocator();         geoposition mygeoposition = await mygeolocator.getgeopositionasync();         geocoordinate mygeocoordinate = mygeoposition.coordinate;          app.lat = mygeocoordinate.latitude;         app.lng = mygeocoordinate.longitude;          this.pushpin(this.mapwithmylocation, mygeocoordinate);     }      protected async override void onnavigatedto(navigationeventargs e)     {         await showmylocationonthemap(geopositionaccuracy.default);         webclient = new webclient();         webclient.downloadstringcompleted += webclient_downloadstringcompleted;         string jsonquery= "www.blabla.com?lat="+app.lat+"&lng="+app.lng;         webclient.downloadstringasync(new uri(jsonquery));     } 

hope helps.