TdxMapItems.Add(TdxMapItemClass) Method

Creates a map item of the required type and adds the item to the collection.

Declaration

delphi

function Add(AMapItemClass: TdxMapItemClass): TdxMapItem;

Parameters

Name	Type	Description
AMapItemClass	TdxMapItemClass

The reference to the required map item class.

Returns

Type	Description
TdxMapItem

The created map item.

To access all public API members of the created map item, cast the returned object to the corresponding terminal TdxMapItem class descendant (AMapItemClass).

Remarks

Call the Add function to create any supported map item and add it to the collection. All created map items are accessible through the Items property.

Code Example: Display a Map Point Address as a Hint

The following code example implements a procedure that uses a configured information provider component to create a pushpin at the specified point on the map and assign the point’s address to the pushpin hint:

Delphi
C++

delphi

uses
  dxAzureMapInformationProviders; // Declares TdxMapControlAzureMapReverseGeocodeProvider
// ...

procedure TMyForm.AddPushpin(AGeoPoint: TdxMapControlGeoPoint);
var
  APushpin: TdxMapPushpin;
  AParams: IdxAzureMapReverseGeocodeQueryParams;
  AResponse: TdxAzureMapReverseGeocodeRequestResponse;
begin
  // Creates a new pushpin on an existing map item layer
  APushpin := dxMapControl1ItemLayer1.MapItems.Add(TdxMapPushpin) as TdxMapPushpin;
  APushpin.Location.GeoPoint := AGeoPoint;
  AParams := dxMapControl1AzureMapReverseGeocodeProvider1.CreateQueryParams;
  AParams.Coordinates := APushpin.Location.GeoPoint;
  // Uses a configured reverse geocode provider to send a query to an Azure Maps server
  dxMapControl1AzureMapReverseGeocodeProvider1.Execute(AParams, AResponse);
  try
    if AResponse <> nil then // Checks if a server response is received
    begin
      if AResponse.IsSuccess and (AResponse.Features.Count > 0) then // Checks if the query is successful
        APushpin.Hint := AResponse.Features.First.Properties.Address.FormattedAddress;
    end;
  finally
    AResponse.Free; // Deletes the query result regardless of the operation's success 
  end;
end;

cpp

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

void __fastcall TMyForm::AddPushpin(TdxMapControlGeoPoint *AGeoPoint)
{
  TdxMapPushpin *APushpin;
  _di_IdxAzureMapReverseGeocodeQueryParams AParams;
  TdxAzureMapReverseGeocodeRequestResponse *AResponse;

  // Creates a new pushpin on an existing map item layer
  APushpin = dynamic_cast<TdxMapPushpin*>(dxMapControl1ItemLayer1->MapItems->Add(__classid(TdxMapPushpin)));
  APushpin->Location->GeoPoint = AGeoPoint;
  AParams = dxMapControl1AzureMapReverseGeocodeProvider1->CreateQueryParams();
  AParams->Coordinates = APushpin->Location->GeoPoint;
  // Uses a configured reverse geocode provider to send a query to an Azure Maps server
  dxMapControl1AzureMapReverseGeocodeProvider1->Execute(AParams, AResponse);
  try
  {
    if(AResponse != nullptr) // Checks if a server response is received
    {
      if((AResponse->IsSuccess) && (AResponse->Features->Count > 0)) // Checks if the query is successful
        APushpin->Hint = AResponse->Features->First()->Properties->Address->FormattedAddress;
    }
  }
  __finally
  {
    delete AResponse; // Deletes the query result response regardless of the operation's success
  }
}