TdxMapControlAzureMapRouteProvider.ExecuteAsync(IdxAzureMapRouteQueryParams) Method

Sends an asynchronous query to an Azure Maps Route server.

Declaration

procedure ExecuteAsync(const AParams: IdxAzureMapRouteQueryParams);

Parameters

Name	Type	Description
AParams	IdxAzureMapRouteQueryParams	Accepts a configured query parameters container. Call the CreateQueryParams function to create a query parameters container.

Remarks

Call the ExecuteAsync procedure to send an asynchronous query to an Azure Maps Route server. To cancel pending asynchronous queries, call the CancelRequests procedure.

Receive Server Responses to Asynchronous Queries

Handle the OnResponse event to receive and process a server query after an ExecuteAsync procedure call.

Code Example: Build a Map Route Asynchronously

The code example in this section demonstrates a procedure that sends a query to an Azure Maps Route server and an OnResponse event handler that receives and processes the server response. The event handler uses an existing map item layer to draw a route between two specified points on a map if the query is successful.

Delphi

uses
  dxAzureMapInformationProviders,  // Declares TdxMapControlAzureMapRouteProvider
  dxMessageDialog,  // Declares the dxMessageDlg global function
  dxCoreGraphics;  // Declares TdxAlphaColors
// ...

procedure TMyForm.SendRouteQuery(ARouteStart, ARouteEnd: TdxMapControlGeoPoint);
var
  AQueryParams: IdxAzureMapRouteQueryParams;
  ARouteWaypoints: TdxMapControlGeoPoints;
begin
  AQueryParams := dxMapControl1AzureMapRouteProvider1.CreateQueryParams;
  SetLength(ARouteWaypoints, 2);
  ARouteWaypoints[0] := ARouteStart;
  ARouteWaypoints[1] := ARouteEnd;
  AQueryParams.WayPoints := ARouteWaypoints;
  AQueryParams.TravelMode := TdxAzureMapRouteTravelMode.Car;
  AQueryParams.MaxAlternatives := 1;
  dxMapControl1AzureMapRouteProvider1.ExecuteAsync(AQueryParams);
end;

procedure TMyForm.dxMapControl1AzureMapRouteProvider1Response(
  ASender: TdxMapControlAzureMapRouteProvider;
  AResponse: TdxAzureMapRouteRequestResponse; var ADestroyResponse: Boolean);
var
  APolyline: TdxMapPolyline;
  ARoute: TdxAzureMapRouteItem;
  I, J: Integer;
begin
  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
      else if Assigned(AResponse.ErrorInfo) then
        dxMessageDlg(AResponse.ErrorInfo.Message, TMsgDlgType.mtError, [mbOK], 0);
    end;
  finally
    dxMapControl1.EndUpdate;  // Calls EndUpdate regardless of the batch operation's success
  end;
end;

C++

#include "dxAzureMapInformationProviders.hpp"  // Declares TdxMapControlAzureMapRouteProvider
#include "dxMessageDialog.hpp"  // Declares the dxMessageDlg global function
#include "dxCoreGraphics.hpp"  // Declares TdxAlphaColors
// ...

void __fastcall TMyForm::SendRouteQuery(TdxMapControlGeoPoint *ARouteStart, TdxMapControlGeoPoint *ARouteEnd)
{
  _di_IdxAzureMapRouteQueryParams AQueryParams;
  TdxMapControlGeoPoints *ARouteWaypoints;
  AQueryParams = dxMapControl1AzureMapRouteProvider1->CreateQueryParams();
  SetLength(ARouteWaypoints, 2);
  ARouteWaypoints[0] = ARouteStart;
  ARouteWaypoints[1] = ARouteEnd;
  AQueryParams->WayPoints = ARouteWaypoints;
  AQueryParams->TravelMode = TdxAzureMapRouteTravelMode::Car;
  AQueryParams->MaxAlternatives = 1;
  dxMapControl1AzureMapRouteProvider1->ExecuteAsync(AQueryParams);
}

void __fastcall TMyForm::dxMapControl1AzureMapRouteProvider1Response(
  TdxMapControlAzureMapRouteProvider *ASender,
  TdxAzureMapRouteRequestResponse *AResponse, bool &ADestroyResponse)
{
  TdxMapItem *AMapItem;
  TdxMapPolyline *APolyline;
  TdxAzureMapRouteItem *ARoute;
  dxMapControl1->BeginUpdate();  // Initiates the following batch change
  try
  {
    if(AResponse != nullptr)
    {
      if(AResponse->IsSuccess)
      {
        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;
      }
      else if(AResponse->ErrorInfo != nullptr)
      {
        dxMessageDlg(AResponse->ErrorInfo->Message, TMsgDlgType::mtError, TMsgDlgButtons() << mbOK, 0);
      }
    }
  }
  __finally
  {
    dxMapControl1->EndUpdate();  // Calls EndUpdate regardless of the batch operation's success
  }
}