Google ReverseGeocoding

[MapMan]

Beim Reverse Geocoding wird aus geografischen Koordinaten (Längengrad, Breitengrad) eine Adresse ermittelt.

Das geht recht einfach mit dem Google ReverseGeocoding-API http://code.google.com/intl/de-DE/ap...verseGeocoding

Eine kleine Klasse kapselt die Kernmethode ReverseGeocode. Zur Kommunikation mit dem API wird ein Indy HTTP-Client verwendet.

Delphi-Quellcode:

const
  Hdr='"formatted_address": "';
  URL='http://maps.google.com/maps/api/geocode/json?latlng=%3.8f,%3.8f&sensor=true';

function TGoogleReverseGeocode.ReverseGeocode(Latitude, Longitude: double):string;
begin
  s:=UTF8Decode(IdHTTP.Get(format(URL,[Latitude, Longitude],FormatSettings)));
  Idx:=pos(Hdr,s);
  if Idx<>0 then
    begin
      Idx:=Idx+22;
      while s[Idx]<>'"' do
        begin
          Result:=Result+s[Idx];
          inc(Idx);
        end;
    end
  else
    Result:='?';
end;

Google liefert eine Menge Daten zurück, interessant ist aber primär die formatierte Adresse.
Wer möchte, kann sich aus dem Abfrageergebis sein individuelles Format erzeugen.

Code:

, 
{
  "status": "OK",
  "results": [ {
    "types": [ "street_address" ],
    "formatted_address": "Schloßstraße 27, 56068 Koblenz, Germany",
    "address_components": [ {
      "long_name": "27",
      "short_name": "27",
      "types": [ "street_number" ]
    }, {
      "long_name": "Schloßstraße",
      "short_name": "Schloßstraße",
      "types": [ "route" ]
    }, {
      "long_name": "Koblenz",
      "short_name": "Koblenz",
      "types": [ "sublocality", "political" ]
    }, {
      "long_name": "Koblenz",
      "short_name": "Koblenz",
      "types": [ "locality", "political" ]
    }, {
      "long_name": "Koblenz",
      "short_name": "KO",
      "types": [ "administrative_area_level_2", "political" ]
    }, {
      "long_name": "Rheinland-Pfalz",
      "short_name": "RP",
      "types": [ "administrative_area_level_1", "political" ]
    }, {
      "long_name": "Germany",
      "short_name": "DE",
      "types": [ "country", "political" ]
    }, {
      "long_name": "56068",
      "short_name": "56068",
      "types": [ "postal_code" ]
    } ],
    "geometry": {
      "location": {
        "lat": 50.3564800,
        "lng": 7.5956700
      },
      "location_type": "ROOFTOP",
      "viewport": {
        "southwest": {
          "lat": 50.3533324,
          "lng": 7.5925224
        },
        "northeast": {
          "lat": 50.3596276,
          "lng": 7.5988176
        }
      }
    }
  }, {
    "types": [ "postal_code" ],
    "formatted_address": "56068 Koblenz, Germany",
    "address_components": [ {
      "long_name": "56068",
      "short_name": "56068",
      "types": [ "postal_code" ]
    }, {
      "long_name": "Koblenz",
      "short_name": "Koblenz",
      "types": [ "locality", "political" ]
    }, {
      "long_name": "Koblenz",
      "short_name": "KO",
      "types": [ "administrative_area_level_2", "political" ]
    }, {
      "long_name": "Rheinland-Pfalz",
      "short_name": "RP",
      "types": [ "administrative_area_level_1", "political" ]
    }, {
      "long_name": "Germany",
      "short_name": "DE",
      "types": [ "country", "political" ]
    } ],
    "geometry": {
      "location": {
        "lat": 50.3511528,
        "lng": 7.5951959
      },
      "location_type": "APPROXIMATE",
      "viewport": {
        "southwest": {
          "lat": 50.3285887,
          "lng": 7.5818021
        },
        "northeast": {
          "lat": 50.3659432,
          "lng": 7.6090369
        }
      },
      "bounds": {
        "southwest": {
          "lat": 50.3285887,
          "lng": 7.5818021
        },
        "northeast": {
          "lat": 50.3659432,
          "lng": 7.6090369
        }
      }
    }
  }, {
    "types": [ "administrative_area_level_2", "political" ],
    "formatted_address": "Koblenz, Germany",
    "address_components": [ {
      "long_name": "Koblenz",
      "short_name": "KO",
      "types": [ "administrative_area_level_2", "political" ]
    }, {
      "long_name": "Rheinland-Pfalz",
      "short_name": "RP",
      "types": [ "administrative_area_level_1", "political" ]
    }, {
      "long_name": "Germany",
      "short_name": "DE",
      "types": [ "country", "political" ]
    } ],
    "geometry": {
      "location": {
        "lat": 50.3386144,
        "lng": 7.5885240
      },
      "location_type": "APPROXIMATE",
      "viewport": {
        "southwest": {
          "lat": 50.2829080,
          "lng": 7.4826460
        },
        "northeast": {
          "lat": 50.4096970,
          "lng": 7.6963740
        }
      },
      "bounds": {
        "southwest": {
          "lat": 50.2829080,
          "lng": 7.4826460
        },
        "northeast": {
          "lat": 50.4096970,
          "lng": 7.6963740
        }
      }
    }
  }, {
    "types": [ "locality", "political" ],
    "formatted_address": "Koblenz, Germany",
    "address_components": [ {
      "long_name": "Koblenz",
      "short_name": "Koblenz",
      "types": [ "locality", "political" ]
    }, {
      "long_name": "Koblenz",
      "short_name": "KO",
      "types": [ "administrative_area_level_2", "political" ]
    }, {
      "long_name": "Rheinland-Pfalz",
      "short_name": "RP",
      "types": [ "administrative_area_level_1", "political" ]
    }, {
      "long_name": "Germany",
      "short_name": "DE",
      "types": [ "country", "political" ]
    } ],
    "geometry": {
      "location": {
        "lat": 50.3566962,
        "lng": 7.5996166
      },
      "location_type": "APPROXIMATE",
      "viewport": {
        "southwest": {
          "lat": 50.2829080,
          "lng": 7.4826460
        },
        "northeast": {
          "lat": 50.4096970,
          "lng": 7.6963740
        }
      },
      "bounds": {
        "southwest": {
          "lat": 50.2829080,
          "lng": 7.4826460
        },
        "northeast": {
          "lat": 50.4096970,
          "lng": 7.6963740
        }
      }
    }
  }, {
    "types": [ "administrative_area_level_1", "political" ],
    "formatted_address": "Rhineland-Palatinate, Germany",
    "address_components": [ {
      "long_name": "Rheinland-Pfalz",
      "short_name": "RP",
      "types": [ "administrative_area_level_1", "political" ]
    }, {
      "long_name": "Germany",
      "short_name": "DE",
      "types": [ "country", "political" ]
    } ],
    "geometry": {
      "location": {
        "lat": 50.1183460,
        "lng": 7.3089527
      },
      "location_type": "APPROXIMATE",
      "viewport": {
        "southwest": {
          "lat": 48.9666617,
          "lng": 6.1123660
        },
        "northeast": {
          "lat": 50.9423250,
          "lng": 8.5081190
        }
      },
      "bounds": {
        "southwest": {
          "lat": 48.9666617,
          "lng": 6.1123660
        },
        "northeast": {
          "lat": 50.9423250,
          "lng": 8.5081190
        }
      }
    }
  }, {
    "types": [ "country", "political" ],
    "formatted_address": "Germany",
    "address_components": [ {
      "long_name": "Germany",
      "short_name": "DE",
      "types": [ "country", "political" ]
    } ],
    "geometry": {
      "location": {
        "lat": 51.1656910,
        "lng": 10.4515260
      },
      "location_type": "APPROXIMATE",
      "viewport": {
        "southwest": {
          "lat": 47.2701270,
          "lng": 5.8662579
        },
        "northeast": {
          "lat": 55.0815000,
          "lng": 15.0418321
        }
      },
      "bounds": {
        "southwest": {
          "lat": 47.2701270,
          "lng": 5.8662579
        },
        "northeast": {
          "lat": 55.0815000,
          "lng": 15.0418321
        }
      }
    }
  } ]
}

Im Anhang die Demo-App