public virtual async Task <ImageCacheItem> GetAsync(string key)
{
var item = await rootFolder.TryGetItemAsync(key);
if (item == null || !item.IsOfType(StorageItemTypes.File))
{
return(null);
}
var file = (StorageFile)item;
var cacheItem = new ImageCacheItem
{
Buffer = await FileIO.ReadBufferAsync(file)
};
try
{
// Use ImageProperties.DateTaken to get expiration date
var imageProperties = await file.Properties.GetImagePropertiesAsync();
cacheItem.Expires = imageProperties.DateTaken.UtcDateTime;
}
catch
{
}
//Debug.WriteLine("Loaded cached image {0}", file.Path);
return(cacheItem);
}
public virtual async Task<ImageCacheItem> GetAsync(string key)
{
var item = await rootFolder.TryGetItemAsync(key);
if (item == null || !item.IsOfType(StorageItemTypes.File))
{
return null;
}
var file = (StorageFile)item;
var cacheItem = new ImageCacheItem
{
Buffer = await FileIO.ReadBufferAsync(file)
};
try
{
// Use ImageProperties.DateTaken to get expiration date
var imageProperties = await file.Properties.GetImagePropertiesAsync();
cacheItem.Expires = imageProperties.DateTaken.UtcDateTime;
}
catch
{
}
//Debug.WriteLine("Loaded cached image {0}", file.Path);
return cacheItem;
}
public override object Get(string key, string regionName = null)
{
if (regionName != null)
{
throw new NotSupportedException("ImageFileCache does not support named regions.");
}
if (key == null)
{
throw new ArgumentNullException("The parameter key must not be null.");
}
var imageCacheItem = memoryCache.Get(key) as ImageCacheItem;
if (imageCacheItem == null)
{
var path = FindFile(key);
if (path != null)
{
try
{
var buffer = File.ReadAllBytes(path);
if (buffer.Length > 16 && Encoding.ASCII.GetString(buffer, buffer.Length - 16, 8) == "EXPIRES:")
{
var expiration = new DateTime(BitConverter.ToInt64(buffer, buffer.Length - 8), DateTimeKind.Utc);
Array.Resize(ref buffer, buffer.Length - 16);
imageCacheItem = new ImageCacheItem
{
Buffer = buffer,
Expiration = expiration
};
memoryCache.Set(key, imageCacheItem, new CacheItemPolicy {
AbsoluteExpiration = expiration
});
//Debug.WriteLine("ImageFileCache: Reading {0}, Expires {1}", path, imageCacheItem.Expiration.ToLocalTime());
}
}
catch (Exception ex)
{
Debug.WriteLine("ImageFileCache: Failed reading {0}: {1}", path, ex.Message);
}
}
}
return(imageCacheItem);
}
public override object Get(string key, string regionName = null)
{
if (regionName != null)
{
throw new NotSupportedException("ImageFileCache does not support named regions.");
}
if (key == null)
{
throw new ArgumentNullException("The parameter key must not be null.");
}
var imageCacheItem = memoryCache.Get(key) as ImageCacheItem;
if (imageCacheItem == null)
{
var path = FindFile(key);
if (path != null)
{
try
{
var buffer = File.ReadAllBytes(path);
var expiration = GetExpiration(ref buffer);
imageCacheItem = new ImageCacheItem
{
Buffer = buffer,
Expiration = expiration
};
memoryCache.Set(key, imageCacheItem, new CacheItemPolicy {
AbsoluteExpiration = expiration
});
//Debug.WriteLine("ImageFileCache: Reading {0}, Expires {1}", path, imageCacheItem.Expiration.ToLocalTime());
}
catch (Exception ex)
{
Debug.WriteLine("ImageFileCache: Failed reading {0}: {1}", path, ex.Message);
}
}
}
return(imageCacheItem);
}
