TdxMapControlAzureMapRouteProvider.CreateQueryParams Method

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

Declaration

function CreateQueryParams: IdxAzureMapRouteQueryParams;

Returns

Type	Description
IdxAzureMapRouteQueryParams	Stores Azure Maps Route query parameters.

Remarks

Call the CreateQueryParams function to create and configure server query parameters before an Execute or ExecuteAsync procedure call.

Asynchronous Queries and Server Responses

To receive and process a response from an Azure Maps server after an ExecuteAsync procedure call, handle the OnResponse event.

Code Example: Draw a Map Route

The following code example uses a configured information provider to draw a route between two specified points on a map:

Delphi

uses
  dxAzureMapInformationProviders,  // Declares TdxMapControlAzureMapRouteProvider
  dxCoreGraphics;  // Declares TdxAlphaColors
// ...

procedure TMyForm.DrawMapRoute(ARouteStart, ARouteEnd: TdxMapControlGeoPoint);
var
  APolyline: TdxMapPolyline;
  ARoute: TdxAzureMapRouteItem;
  AParams: IdxAzureMapRouteQueryParams;
  AResponse: TdxAzureMapRouteRequestResponse;
  ARouteWaypoints: TdxMapControlGeoPoints;
  I, J: Integer;
begin
  AParams := dxMapControl1AzureMapRouteProvider1.CreateQueryParams;
  SetLength(ARouteWaypoints, 2);
  ARouteWaypoints[0] := ARouteStart;
  ARouteWaypoints[1] := ARouteEnd;
  AParams.WayPoints := ARouteWaypoints;
  AParams.TravelMode := TdxAzureMapRouteTravelMode.Car;
  AParams.MaxAlternatives := 1;
  dxMapControl1AzureMapRouteProvider1.Execute(AParams, AResponse);
  dxMapControl1.BeginUpdate;  // Initiates the following batch change
  try
    if AResponse <> nil then
    begin
      if AResponse.IsSuccess then  // Draws a route if a valid server response is received
      begin
        APolyline := dxMapControl1ItemLayer1.AddItem(TdxMapPolyline) as TdxMapPolyline;
        ARoute := AResponse.Routes.Items[0];  // Selects the first returned route
        for I := 0 to ARoute.Legs.Count - 1 do
          for J := 0 to ARoute.Legs.Items[I].Points.Count - 1 do
            APolyline.GeoPoints.Add.GeoPoint := ARoute.Legs.Items[I].Points.Items[J];

        APolyline.Style.BorderWidth := 4;
        APolyline.Style.BorderColor := TdxAlphaColors.DarkBlue;
      end;
    end;
  finally
    dxMapControl1.EndUpdate;  // Calls EndUpdate regardless of the batch operation's success
  end;
end;

C++

#include "dxAzureMapInformationProviders.hpp"  // Declares TdxMapControlAzureMapRouteProvider
#include "dxCoreGraphics.hpp"  // Declares TdxAlphaColors
// ...

void __fastcall TMyForm::ValidateServerResponse(TdxMapControlGeoPoint *ARouteStart,
  TdxMapControlGeoPoint *ARouteEnd)
{
  TdxMapItem *AMapItem;
  TdxMapPolyline *APolyline;
  TdxAzureMapRouteItem *ARoute;
  _di_IdxAzureMapRouteQueryParams AParams;
  TdxAzureMapRouteRequestResponse *AResponse;
  TdxMapControlGeoPoints *ARouteWaypoints;

  AParams = dxMapControl1AzureMapRouteProvider1->CreateQueryParams();
  SetLength(ARouteWaypoints, 2);
  ARouteWaypoints[0] = ARouteStart;
  ARouteWaypoints[1] = ARouteEnd;
  AParams->WayPoints = ARouteWaypoints;
  AParams->TravelMode = TdxAzureMapRouteTravelMode::Car;
  AParams->MaxAlternatives = 1;
  dxMapControl1AzureMapRouteProvider1->Execute(AParams, AResponse);
  dxMapControl1->BeginUpdate();  // Initiates the following batch change
  try
  {
    if(AResponse != nullptr)
    {
      if(AResponse->IsSuccess)  // Draws a route if a valid server response is received
      {
        AMapItem = dxMapControl1ItemLayer1->AddItem(__classid(TdxMapPolyline));
        APolyline = dynamic_cast<TdxMapPolyline*>(AMapItem);
        ARoute = AResponse->Routes->Items[0]; // Selects the first returned route
        for(int i = 0; i < ARoute->Legs->Count; i++)
          for(int j = 0; j < ARoute->Legs->Items[i]->Points->Count; j++)
            APolyline->GeoPoints->Add()->GeoPoint = ARoute->Legs->Items[i]->Points->Items[j];

        APolyline->Style->BorderWidth = 4;
        APolyline->Style->BorderColor = TdxAlphaColors::DarkBlue;
      }
    }
  }
  __finally
  {
    dxMapControl1->EndUpdate();  // Calls EndUpdate regardless of tha batch operation's success
  }
}