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TdxAzureMapReverseGeocodeProviderOnResponse Type

The procedural type for Azure Maps Reverse Geocode server response events.

#Declaration

Delphi
TdxAzureMapReverseGeocodeProviderOnResponse = procedure(ASender: TdxMapControlAzureMapReverseGeocodeProvider; AResponse: TdxAzureMapReverseGeocodeRequestResponse; var ADestroyResponse: Boolean) of object;

#Parameters

Name Type Description
ASender TdxMapControlAzureMapReverseGeocodeProvider

Provides access to the Azure Maps Reverse Geocode information component that raised the server response event.

AResponse TdxAzureMapReverseGeocodeRequestResponse

Provides access to a container populated with information returned by a server.

ADestroyResponse Boolean

Specifies if the response event handler automatically destroys the information container accessible through the AResponse parameter. The event handler creates a new server response information container every time the event occurs.

True
Default. The AResponse container is destroyed automatically once the application exits the current event handler. You do not need to manage the response information container manually.
False

Use this option if you need to use the returned information container outside the server response event handler.

Important

Call the Free procedure (in Delphi) or use the delete keyword (in C++Builder) to destroy [TdxAzureMapReverseGeocodeRequestResponse] class instances manually if you set the ADestroyResponse parameter to False. Otherwise, memory leaks will occur.

#Remarks

Response events allow you to receive and process a server response after an asynchronous query.

#Code Example: Obtain Map Point Address Asynchronously

The code example in this section demonstrates a procedure that sends a query to an Azure Maps Reverse Geocode server and an OnResponse event handler that receives and processes the server response.

uses
  dxAzureMapInformationProviders, // Declares TdxMapControlAzureMapReverseGeocodeProvider
  dxMessageDialog;  // Declares the dxMessageDlg global function
// ...

procedure TMyForm.AddPushpin(AGeoPoint: TdxMapControlGeoPoint): Boolean;
var
  APushpin: TdxMapPushpin;
  AQueryParams: IdxAzureMapReverseGeocodeQueryParams;
begin
  // Creates a new pushpin on an existing map item layer
  APushpin := dxMapControl1ItemLayer1.MapItems.Add(TdxMapPushpin) as TdxMapPushpin;
  APushpin.Location.GeoPoint := AGeoPoint;
  AQueryParams := dxMapControl1AzureMapReverseGeocodeProvider1.CreateQueryParams;
  AQueryParams.Coordinates := APushpin.Location.GeoPoint;
  // Uses a configured reverse geocode provider to send a query to an Azure Maps server
  dxMapControl1AzureMapReverseGeocodeProvider1.ExecuteAsync(AQueryParams);
end;

procedure TMyForm.dxMapControl1AzureMapReverseGeocodeProvider1Response(
  ASender: TdxMapControlAzureMapReverseGeocodeProvider;
  AResponse: TdxAzureMapReverseGeocodeRequestResponse; var ADestroyResponse: Boolean);
var
  AMapItems: TdxMapItems;
  APushpin: TdxMapPushpin;
begin
  AMapItems := dxMapControl1ItemLayer1.MapItems;
  if AResponse <> nil then
  begin
    if AResponse.IsSuccess and (AResponse.Features.Count > 0) then // Checks if the query is successful
    begin
      APushpin := AMapItems.Items[AMapItems.Count - 1] as TdxMapPushpin;
      APushpin.Hint := AResponse.Features.First.Properties.Address.FormattedAddress;
    end
    else if Assigned(AResponse.ErrorInfo) then
      dxMessageDlg(AResponse.ErrorInfo.Message, TMsgDlgType.mtError, [mkOK], 0);
  end;
end;

#Direct TdxAzureMapReverseGeocodeProviderOnResponse Type Reference

The TdxMapControlAzureMapReverseGeocodeProvider.OnResponse event references the TdxAzureMapReverseGeocodeProviderOnResponse procedural type.

See Also