TdxMapControlAzureMapGeocodeProvider Class

An Azure Maps Geocode information provider.

Declaration

TdxMapControlAzureMapGeocodeProvider = class(
    TdxMapControlAzureMapInformationProvider
)

Remarks

The TdxMapControlAzureMapGeocodeProvider component allows you to use Azure Maps Geocode services to obtain geographical coordinates (longitude and latitude) of a street address or name of a place.

Azure Maps Account

To use Microsoft Azure Maps® services, you need to create an Azure Maps account and obtain a key. Assign the account key to the AzureKey property to configure the information provider.

Main API Members

The list below outlines key members of the TdxMapControlAzureMapGeocodeProvider class. These members allow you to access Azure Maps services and obtain coordinates of a street address or a place.

Server-Related API Members

AzureKey

Required. Specifies the account key required to use the Azure geocode provider.

CancelRequests

Cancels pending asynchronous queries to Azure Maps servers.

CreateQueryParams

Creates an information container required to send a geocode query to an Azure Maps server.

Execute | ExecuteAsync

Send a query created by a CreateQueryParams function call.

OnResponse

Allows you to receive and process a server response after an asynchronous query.

Collection-Related API Members

Collection

Provides access to the parent collection.

DisplayName

Specifies the information provider’s name displayed in the design-time collection editor dialog.

Index

Specifies the information provider’s index in the parent collection.

ID

Returns the component’s unique identifier.

Code Examples

Create and Configure Azure Maps Information Providers

The following code example implements a procedure that accepts an Azure Maps account key, and creates and configures all Azure Maps information provider components:

Delphi

uses
  dxAzureMapInformationProviders;  // Declares all Azure Maps information provider classes
// ...

procedure TMyForm.CreateAzureMapsInformationProviders(const AAzureKey: string);
var
  AProviders: TdxMapControlInformationProviders;
  AProvider: TdxMapControlAzureMapInformationProvider;
  I: Integer;
begin
  AProviders := dxMapControl1.InformationProviders;
  AProviders.BeginUpdate;  // Initiates the following batch change
  try
    // Create all Azure Maps information providers
    AProviders.Add(TdxMapControlAzureMapGeocodeProvider);
    AProviders.Add(TdxMapControlAzureMapGeolocationProvider);
    AProviders.Add(TdxMapControlAzureMapReverseGeocodeProvider);
    AProviders.Add(TdxMapControlAzureMapRouteProvider);
    for I := 0 to AProviders.Count - 1 do  // Iterates through all created information providers
    begin
      AProvider := AProviders.Items[I] as TdxMapControlAzureMapInformationProvider;
      AProvider.AzureKey := AAzureKey;  // Assigns the same Azure Maps account key to all providers
    end;
  finally
    AProviders.EndUpdate;  // Calls EndUpdate regardless of the batch operation's success
  end;
end;

C++

#include "dxAzureMapInformationProviders.hpp"  // Declares all Azure Maps information provider classes
// ...

void __fastcall TMyForm::CreateAzureMapsInformationProviders(const UnicodeString &AAzureKey)
{
  TdxMapControlInformationProviders *AProviders;
  TdxMapControlAzureMapInformationProvider *AProvider;

  AProviders = dxMapControl1->InformationProviders;
  AProviders->BeginUpdate();  // Initiates the following batch change
  try
  {
    // Create all Azure Maps information providers
    AProviders->Add(__classid(TdxMapControlAzureMapGeocodeProvider));
    AProviders->Add(__classid(TdxMapControlAzureMapGeolocationProvider));
    AProviders->Add(__classid(TdxMapControlAzureMapReverseGeocodeProvider));
    AProviders->Add(__classid(TdxMapControlAzureMapRouteProvider));
    for(int i = 0; i < AProviders->Count; i++)  // Iterates through all created information providers
    {
      AProvider = dynamic_cast<TdxMapControlAzureMapInformationProvider*>(AProviders->Items[i]);
      AProvider->AzureKey = AAzureKey;  // Assigns the same Azure Maps account key to all providers
    }
  }
  __finally
  {
    AProviders->EndUpdate();  // Calls EndUpdate regardless of the batch operation's success
  }
}

Obtain Point Coordinates by Address

The following code example implements a function that uses a configured information provider component to return the point on a map that corresponds to the specified address:

Delphi

uses
  dxAzureMapInformationProviders;  // Declares TdxMapControlAzureMapGeocodeProvider
// ...

function TMyForm.GetAddressCoordinates(const AAddress: string): TdxMapControlGeoPoint;
var
  AParams: IdxAzureMapGeocodeQueryParams;
  AResponse: TdxAzureMapGeocodeRequestResponse;
  AGeometry: TGeoJSONGeometry;
begin
  AResult := nil;
  AParams := dxMapControl1AzureMapGeocodeProvider1.CreateQueryParams;
  AParams.Query := AAddress;
  dxMapControl1AzureMapGeocodeProvider1.Execute(AParams, AResponse);
  if AResponse <> nil then
  begin
    if AResponse.IsSuccess then
    begin
      AGeometry := AResponse.Features.First.Geometry;
      AResult := TdxMapControlGeoPoint.Create(AGeometry.Coordinates[1], AGeometry.Coordinates[0]);
    end;
  end;
end;

C++

#include "dxAzureMapInformationProviders.hpp"  // Declares TdxMapControlAzureMapGeocodeProvider
// ...

TdxMapControlGeoPoint* __fastcall TMyForm::GetAddressCoordinates(const UnicodeString &AAddress)
{
  _di_IdxAzureMapGeocodeQueryParams AParams;
  TdxAzureMapGeocodeRequestResponse *AResponse;
  TGeoJSONGeometry *AGeometry;

  AParams = dxMapControl1AzureMapGeocodeProvider1->CreateQueryParams();
  AParams->Query = AAddress;
  dxMapControl1AzureMapGeocodeProvider1->Execute(AParams, AResponse);
  if(AResponse != nullptr)
  {
    if(AResponse->IsSuccess)
    {
      AGeometry = AResponse->Features->First->Geometry;
      return new TdxMapControlGeoPoint(AGeometry->Coordinates[1], AGeometry->Coordinates[0]);
    }
  }
  return nullptr;
}

Other Azure Maps Information Providers

TdxMapControlAzureMapGeolocationProvider

An Azure Maps Geolocation information provider.

TdxMapControlAzureMapReverseGeocodeProvider

An Azure Maps Reverse Geocode information provider.

TdxMapControlAzureMapRouteProvider

An Azure Maps Route information provider.

Indirect TdxMapControlAzureMapGeocodeProvider Class References

The following public API members reference the TdxMapControlAzureMapGeocodeProvider class as a TdxMapControlInformationProvider object:

TdxMapControlInformationProviders.Add

Creates an auxiliary map information provider of the required type and adds the provider to the collection.

TdxMapControlInformationProviders.Items

Provides indexed access to stored map information provider components.

Direct TdxMapControlAzureMapGeocodeProvider Class Reference

The TdxMapControlInformationProviderClass references the TdxMapControlAzureMapGeocodeProvider class.

Related Compiled Demo

To see Microsoft Azure Map tile and information providers in action, run the Mapping demo in the VCL Demo Center installed with compiled DevExpress demos. When the demo is opened, it downloads tile data and additional information from Azure Map servers to display a map and build routes between specified points.

Download: Compiled VCL Demos

Tip

Compiled DevExpress demos ship with source code installed in the Public Documents folder (%Public%) for all users (default). You can find all project and source code files for the Map Control demo in the following folder:

%Public%\Documents\DevExpress VCL Demos\MegaDemos\Product Demos\ExpressMapControl

Inheritance

TObject

TPersistent

TComponent

TcxCustomComponent

TcxComponentCollectionItem

TdxMapControlInformationProvider

TdxMapControlAzureMapInformationProvider

TdxMapControlAzureMapGeocodeProvider