private async Task LoadCachedTileImageAsync(Tile tile, Uri uri, string cacheKey)
{
var cacheItem = await Cache.GetAsync(cacheKey).ConfigureAwait(false);
var cacheBuffer = cacheItem?.Buffer;
if (cacheBuffer == null || cacheItem.Expiration < DateTime.UtcNow)
{
var response = await ImageLoader.LoadHttpBufferAsync(uri).ConfigureAwait(false);
if (response != null) // download succeeded
{
cacheBuffer = null; // discard cached image
if (response.Buffer != null) // tile image available
{
await LoadTileImageAsync(tile, response.Buffer).ConfigureAwait(false);
await Cache.SetAsync(cacheKey, response.Buffer, GetExpiration(response.MaxAge)).ConfigureAwait(false);
}
}
}
if (cacheBuffer != null) // cached image not expired or download failed
{
await LoadTileImageAsync(tile, cacheBuffer).ConfigureAwait(false);
}
}
private async Task LoadCachedTileImageAsync(Tile tile, Uri uri, string cacheKey)
{
var cacheItem = await Cache.GetAsync(cacheKey);
var cacheBuffer = cacheItem?.Buffer;
if (cacheBuffer == null || cacheItem.Expiration < DateTime.UtcNow)
{
var result = await ImageLoader.LoadHttpBufferAsync(uri);
if (result != null) // download succeeded
{
cacheBuffer = null; // discard cached image
if (result.Item1 != null) // tile image available
{
await LoadTileImageAsync(tile, result.Item1);
await Cache.SetAsync(cacheKey, result.Item1, GetExpiration(result.Item2));
}
}
}
if (cacheBuffer != null)
{
await LoadTileImageAsync(tile, cacheBuffer);
}
}
