TdxAzureMapRouteProviderOnResponse Type
The procedural type for Azure Maps Route server response events.
#Declaration
TdxAzureMapRouteProviderOnResponse = procedure(ASender: TdxMapControlAzureMapRouteProvider; AResponse: TdxAzureMapRouteRequestResponse; var ADestroyResponse: Boolean) of object;
#Parameters
Name | Type | Description |
---|---|---|
ASender | Tdx |
Provides access to the Azure Maps Route information component that raised the server response event. |
AResponse | Tdx |
Provides access to a container populated with information returned by a server. |
ADestroy |
Boolean | Specifies if the response event handler automatically destroys the information container accessible through the
|
#Remarks
Response events allow you to receive and process a server response after an asynchronous query.
#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.
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;
#Direct TdxAzureMapRouteProviderOnResponse Type Reference
The TdxMapControlAzureMapRouteProvider.OnResponse event references the TdxAzureMapRouteProviderOnResponse
procedural type.