/// <summary>
/// Disposes of this instance.
/// </summary>
public void Dispose()
{
if (!_isDisposed)
{
_stream?.Dispose();
_packageReader?.Dispose();
GC.SuppressFinalize(this);
_isDisposed = true;
}
}
/// <summary>
/// Converts IconUrl from PackageItemListViewModel to an image represented by a BitmapSource
/// </summary>
/// <param name="values">An array of two elements containing the IconUri and a generator function of PackageReaderBase objects</param>
/// <param name="targetType">unused</param>
/// <param name="parameter">A BitmapImage that will be used as the default package icon</param>
/// <param name="culture">unused</param>
/// <returns>A BitmapSource with the image</returns>
/// <remarks>
/// We bind to a BitmapImage instead of a Uri so that we can control the decode size, since we are displaying 32x32 images, while many of the images are 128x128 or larger.
/// This leads to a memory savings.
/// </remarks>
public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
{
if (values == null || values.Length == 0)
{
return(null);
}
var iconUrl = values[0] as Uri;
var defaultPackageIcon = parameter as BitmapSource;
if (iconUrl == null)
{
return(null);
}
string cacheKey = GenerateKeyFromIconUri(iconUrl);
var cachedBitmapImage = BitmapImageCache.Get(cacheKey) as BitmapSource;
if (cachedBitmapImage != null)
{
return(cachedBitmapImage);
}
// Some people run on networks with internal NuGet feeds, but no access to the package images on the internet.
// This is meant to detect that kind of case, and stop spamming the network, so the app remains responsive.
if (ErrorFloodGate.IsOpen)
{
return(defaultPackageIcon);
}
var iconBitmapImage = new BitmapImage();
iconBitmapImage.BeginInit();
BitmapSource imageResult;
if (IsEmbeddedIconUri(iconUrl))
{
// Check if we have enough info to read the icon from the package
if (values.Length == 2 && values[1] is Func <PackageReaderBase> lazyReader)
{
try
{
PackageReaderBase reader = lazyReader(); // Always returns a new reader. That avoids using an already disposed one
if (reader is PackageArchiveReader par) // This reader is closed in BitmapImage events
{
var iconEntryNormalized = PathUtility.StripLeadingDirectorySeparators(
Uri.UnescapeDataString(iconUrl.Fragment)
.Substring(1)); // Substring skips the '#' in the URI fragment
iconBitmapImage.StreamSource = par.GetEntry(iconEntryNormalized).Open();
void EmbeddedIcon_DownloadOrDecodeFailed(object sender, ExceptionEventArgs args)
{
reader.Dispose();
CheckForFailedCacheEntry(cacheKey, args);
}
void EmbeddedIcon_DownloadCompleted(object sender, EventArgs args)
{
reader.Dispose();
IconBitmapImage_DownloadCompleted(sender, args);
}
iconBitmapImage.DecodeFailed += EmbeddedIcon_DownloadOrDecodeFailed;
iconBitmapImage.DownloadFailed += EmbeddedIcon_DownloadOrDecodeFailed;
iconBitmapImage.DownloadCompleted += EmbeddedIcon_DownloadCompleted;
imageResult = FinishImageProcessing(iconBitmapImage, iconUrl, defaultPackageIcon);
}
else // we cannot use the reader object
{
reader?.Dispose();
AddToCache(cacheKey, defaultPackageIcon);
imageResult = defaultPackageIcon;
}
}
catch (Exception)
{
AddToCache(cacheKey, defaultPackageIcon);
imageResult = defaultPackageIcon;
}
}
else // Identified an embedded icon URI, but we are unable to process it
{
AddToCache(cacheKey, defaultPackageIcon);
imageResult = defaultPackageIcon;
}
}
else
{
iconBitmapImage.UriSource = iconUrl;
iconBitmapImage.DecodeFailed += IconBitmapImage_DownloadOrDecodeFailed;
iconBitmapImage.DownloadFailed += IconBitmapImage_DownloadOrDecodeFailed;
iconBitmapImage.DownloadCompleted += IconBitmapImage_DownloadCompleted;
imageResult = FinishImageProcessing(iconBitmapImage, iconUrl, defaultPackageIcon);
}
return(imageResult);
}
public void Dispose()
{
_stream?.Dispose();
_packageReader?.Dispose();
}
