/// <summary>
/// Returns the thumbnail image for the given item.
/// </summary>
/// <param name="key">Item key.</param>
/// <param name="size">Requested image size.</param>
/// <param name="useEmbeddedThumbnails">Embedded thumbnail usage.</param>
/// <param name="useExifOrientation">true to automatically rotate images based on Exif orientation; otherwise false.</param>
/// <param name="useWIC">true to use Windows Imaging Component; otherwise false.</param>
/// <returns>The thumbnail image from the given item or null if an error occurs.</returns>
public override Image GetThumbnail(object key, Size size, UseEmbeddedThumbnails useEmbeddedThumbnails, bool useExifOrientation, bool useWIC)
{
if (disposed)
{
return(null);
}
string uri = (string)key;
try
{
using (WebClient client = new WebClient())
{
byte[] imageData = client.DownloadData(uri);
using (MemoryStream stream = new MemoryStream(imageData))
{
using (Image sourceImage = Image.FromStream(stream))
{
return(ThumbnailExtractor.FromImage(sourceImage, size, useEmbeddedThumbnails, useExifOrientation, useWIC));
}
}
}
}
catch
{
return(null);
}
}
/// <summary>
/// Adds a virtual item to the cache.
/// </summary>
/// <param name="guid">The guid representing this item.</param>
/// <param name="adaptor">The adaptor for this item.</param>
/// <param name="key">The key of this item.</param>
/// <param name="thumbSize">Requested thumbnail size.</param>
/// <param name="thumb">Thumbnail image to add to cache.</param>
/// <param name="useEmbeddedThumbnails">UseEmbeddedThumbnails property of the owner control.</param>
/// <param name="autoRotate">AutoRotate property of the owner control.</param>
/// <param name="useWIC">Whether to use WIC.</param>
public void Add(Guid guid, ImageListView.ImageListViewItemAdaptor adaptor, object key, Size thumbSize, Image thumb, UseEmbeddedThumbnails useEmbeddedThumbnails, bool autoRotate, bool useWIC)
{
// Already cached?
CacheItem item = null;
if (thumbCache.TryGetValue(guid, out item))
{
if (item.Size == thumbSize && item.UseEmbeddedThumbnails == useEmbeddedThumbnails)
{
return;
}
}
// Resize
thumb = ThumbnailExtractor.FromImage(thumb, thumbSize, useEmbeddedThumbnails, autoRotate, useWIC);
// Add to cache
thumbCache.Add(guid, new CacheItem(guid, thumbSize, thumb, CacheState.Cached, useEmbeddedThumbnails, autoRotate, useWIC));
// Add to disk cache
using (MemoryStream stream = new MemoryStream())
{
string diskCacheKey = adaptor.GetUniqueIdentifier(key, thumbSize, useEmbeddedThumbnails, autoRotate, useWIC);
thumb.Save(stream, System.Drawing.Imaging.ImageFormat.Png);
diskCache.Write(diskCacheKey, stream);
}
// Raise the cache events
if (mImageListView != null)
{
mImageListView.OnThumbnailCachedInternal(guid, thumb, thumbSize, true);
mImageListView.Refresh();
}
}
/// <summary>
/// Returns the thumbnail image for the given item.
/// </summary>
/// <param name="key">Item key.</param>
/// <param name="size">Requested image size.</param>
/// <param name="useEmbeddedThumbnails">Embedded thumbnail usage.</param>
/// <param name="useExifOrientation">true to automatically rotate images based on Exif orientation; otherwise false.</param>
/// <param name="useWIC">true to use Windows Imaging Component; otherwise false.</param>
/// <returns>The thumbnail image from the given item or null if an error occurs.</returns>
public override Image GetThumbnail(object key, Size size, UseEmbeddedThumbnails useEmbeddedThumbnails, bool useExifOrientation, bool useWIC)
{
if (disposed)
{
return(null);
}
string filename = (string)key;
if (File.Exists(filename))
{
return(ThumbnailExtractor.FromFile(filename, size, useEmbeddedThumbnails, useExifOrientation, useWIC));
}
else
{
return(null);
}
}