TdxMapControlAzureMapImageryDataProvider.BeginUpdate Method

Postpones all requests to Azure Maps servers until an EndUpdate procedure call.

Declaration

procedure BeginUpdate;

Remarks

Every time you change a tile provider’s settings (for example, change the active tileset), the provider sends a request to Azure servers to download corresponding data. Enclose multiple provider setting changes between BeginUpdate and EndUpdate procedure calls to avoid excessive data requests and improve performance.

Note

Ensure that every BeginUpdate procedure call is followed by an EndUpdate call, even if an exception occurs. Otherwise, the current tile layer remains unable to update tile data.

Code Example: Add a Tile Map Layer and Load Azure Maps Data

The following code example implements a procedure that accepts an Azure Maps account key, creates and configures a map tile layer, and loads data:

Delphi

uses
  dxAzureMapImageryDataProvider;  // Declares TdxMapControlAzureMapImageryDataProvider
// ...

procedure TMyForm.AddAzureMapLayer(const AAzureKey: string);
var
  ATileLayer: TdxMapImageTileLayer;
  AProvider: TdxMapControlAzureMapImageryDataProvider;
begin
  ATileLayer := dxMapControl1.Layers.Add(TdxMapImageTileLayer) as TdxMapImageTileLayer;
  ATileLayer.ProviderClass := TdxMapControlAzureMapImageryDataProvider;
  AProvider := ATileLayer.Provider as TdxMapControlAzureMapImageryDataProvider;
  AProvider.BeginUpdate;  // Initiates the following batch change
  try
    AProvider.AzureKey := AAzureKey;  // Assigns the Azure account key
    AProvider.Tileset := TdxAzureMapTileset.Satellite;  // Changes the default tileset
    AProvider.MaxParallelConnectionCount := 8;  // Explicitly defines the number of parallel connections
  finally
    AProvider.EndUpdate;  // Calls EndUpdate regardless of the batch operation's success
  end;
end;

C++

#include "dxAzureMapImageryDataProvider.hpp"  // Declares TdxMapControlAzureMapImageryDataProvider
// ...

void __fastcall TMyForm::AddAzureMapLayer(const UnicodeString &AAzureKey)
{
  TdxMapLayer *ALayer;
  TdxMapImageTileLayer *ATileLayer;
  TdxMapControlAzureMapImageryDataProvider *AProvider;

  ALayer = dxMapControl1->Layers->Add(__classid(TdxMapImageTileLayer));
  ATileLayer = dynamic_cast<TdxMapImageTileLayer*>(ALayer);
  ATileLayer->ProviderClass = __classid(TdxMapControlAzureMapImageryDataProvider);
  AProvider = dynamic_cast<TdxMapControlAzureMapImageryDataProvider*>(ATileLayer->Provider);
  AProvider->BeginUpdate();  // Initiates the following batch change
  try
  {
    AProvider->AzureKey = AAzureKey;  // Assigns the Azure account key
    AProvider->Tileset = TdxAzureMapTileset::Satellite;  // Changes the default tileset
    AProvider->MaxParallelConnectionCount = 8;  // Explicitly defines the number of parallel connections
  }
  __finally
  {
    AProvider->EndUpdate();  // Calls EndUpdate regardless of the batch operation's success
  }
}