public override void CancelDownload(TileInfo tileInfo)
{
lock (this.webClientsPoolLockObject)
{
if (this.webClientsPool.ContainsKey(tileInfo.Id))
{
this.webClientsPool[tileInfo.Id].CancelAsync();
ImageTileDownloader imageTileDownloader = this;
this.webClientsPool[tileInfo.Id].DownloadDataCompleted -= new DownloadDataCompletedEventHandler(imageTileDownloader.DownloadTileDataCompleted);
this.webClientsPool.Remove(tileInfo.Id);
this.webRequestCache.Remove(tileInfo.Id);
}
}
}
public override void StartDownload(Uri tileUri, TileInfo tileInfo)
{
if (TileCache != null)
{
byte[] bytes = TileCache.Read(tileInfo);
if (bytes != null)
{
tileInfo.Content = bytes;
// raise the event
this.OnTileDownloadComplete(new TileInfoEventArgs(tileInfo));
return;
}
}
lock (this.webClientsPoolLockObject)
{
if (!this.webClientsPool.ContainsKey(tileInfo.Id))
{
WebClient webClient = new WebClient();
if (Credentials != null)
{
webClient.Credentials = Credentials;
}
if (WebProxy != null)
{
webClient.Proxy = WebProxy;
}
this.webClientsPool.Add(tileInfo.Id, webClient);
this.webRequestCache.Add(tileInfo.Id, tileUri);
ImageTileDownloader imageTileDownloader = this;
webClient.DownloadDataCompleted += new DownloadDataCompletedEventHandler(imageTileDownloader.DownloadTileDataCompleted);
webClient.DownloadDataAsync(tileUri, tileInfo);
}
}
}
protected virtual void DownloadTileDataCompleted(object sender, DownloadDataCompletedEventArgs e)
{
TileInfo userState = (TileInfo)e.UserState;
if (e.Error == null)
{
userState.Content = e.Result;
// if tileCache is applied, cache the request tile
if (TileCache != null)
{
TileCache.Save(userState, userState.Content);
}
this.OnTileDownloadComplete(new TileInfoEventArgs(userState));
lock (this.webClientsPoolLockObject)
{
ImageTileDownloader imageTileDownloader = this;
this.webClientsPool[userState.Id].DownloadDataCompleted -= new DownloadDataCompletedEventHandler(imageTileDownloader.DownloadTileDataCompleted);
this.webClientsPool.Remove(userState.Id);
this.webRequestCache.Remove(userState.Id);
}
}
else if (this.ShouldRetryDownload(e.Error))
{
Uri item = this.webRequestCache[userState.Id];
lock (this.webClientsPoolLockObject)
{
item = new Uri(this.webClientsPool[userState.Id].BaseAddress);
ImageTileDownloader imageTileDownloader = this;
this.webClientsPool[userState.Id].DownloadDataCompleted -= new DownloadDataCompletedEventHandler(imageTileDownloader.DownloadTileDataCompleted);
this.webClientsPool.Remove(userState.Id);
this.webRequestCache.Remove(userState.Id);
}
this.StartDownload(item, userState);
}
}
protected virtual TileDownloader CreateTileDownloader(TileSchema tileSchema)
{
TileDownloader tileDownloader = new ImageTileDownloader(tileSchema);
return(tileDownloader);
}
