TdxAzureMapReverseGeocodeProviderOnResponse Type

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

Declaration

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.

Delphi

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;

C++

#include "dxAzureMapInformationProviders.hpp"  // Declares TdxMapControlAzureMapReverseGeocodeProvider
#include "dxMessageDialog.hpp"  // Declares the dxMessageDlg global function
// ...

void __fastcall TMyForm::AddPushpin(TdxMapControlGeoPoint *AGeoPoint)
{
  TdxMapPushpin *APushpin;
  _di_IdxAzureMapReverseGeocodeQueryParams AQueryParams;
  // Creates a new pushpin on an existing map item layer
  APushpin = dynamic_cast<TdxMapPushpin*>(dxMapControl1ItemLayer1->MapItems->Add(__classid(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);
}

void __fastcall TMyForm::dxMapControl1AzureMapReverseGeocodeProvider1Response(
  TdxMapControlAzureMapReverseGeocodeProvider *ASender,
  TdxAzureMapReverseGeocodeRequestResponse *AResponse, bool &ADestroyResponse)
{
  TdxMapItems *AMapItems;
  TdxMapPushpin *APushpin;
  AMapItems = dxMapControl1ItemLayer1->MapItems;
  if(AResponse != nullptr)
  {
    if((AResponse->IsSuccess) && (AResponse->Features->Count > 0))  // Checks if the query is successful
    {
      APushpin = dynamic_cast<TdxMapPushpin*>(AMapItems->Items[AMapItems->Count - 1]);
      APushpin->Hint = AResponse->Features->Properties->Address->FormattedAddress;
    }
    else if(AResponse->ErrorInfo != nullptr)
    {
      dxMessageDlg(AResponse->ErrorInfo->Message, TMsgDlgType::mtError, TMsgDlgButtons() << mbOK, 0);
    }
  }
}

Direct TdxAzureMapReverseGeocodeProviderOnResponse Type Reference

The TdxMapControlAzureMapReverseGeocodeProvider.OnResponse event references the TdxAzureMapReverseGeocodeProviderOnResponse procedural type.