private async Task LoadCachedTileImageAsync(Tile tile, Uri uri, string cacheKey)
{
ImageSource image = null;
DateTime expiration;
var cacheBuffer = GetCachedImage(cacheKey, out expiration);
if (cacheBuffer == null || expiration < DateTime.UtcNow)
{
var response = await ImageLoader.LoadHttpStreamAsync(uri).ConfigureAwait(false);
if (response != null) // download succeeded
{
cacheBuffer = null; // discard cached image
if (response.Stream != null) // tile image available
{
using (var stream = response.Stream)
{
image = ImageLoader.LoadImage(stream);
SetCachedImage(cacheKey, stream, GetExpiration(response.MaxAge));
}
}
}
}
if (cacheBuffer != null) // cached image not expired or download failed
{
image = ImageLoader.LoadImage(cacheBuffer);
}
if (image != null)
{
SetTileImage(tile, image);
}
}
private async Task LoadCachedTileImageAsync(Tile tile, Uri uri, string cacheKey)
{
DateTime expiration;
var cacheBuffer = GetCachedImage(cacheKey, out expiration);
if (cacheBuffer == null || expiration < DateTime.UtcNow)
{
var result = await ImageLoader.LoadHttpStreamAsync(uri);
if (result != null) // download succeeded
{
cacheBuffer = null; // discard cached image
if (result.Item1 != null) // tile image available
{
using (var stream = result.Item1)
{
LoadTileImage(tile, stream);
SetCachedImage(cacheKey, stream, GetExpiration(result.Item2));
}
}
}
}
if (cacheBuffer != null)
{
using (var stream = new MemoryStream(cacheBuffer))
{
LoadTileImage(tile, stream);
}
}
}