// Requests all image of the assetCollections to be fetched.
public override void ViewDidLoad()
{
base.ViewDidLoad();
var assetCollection = AssetCollection;
if (assetCollection == null)
{
return;
}
var items = PHAsset.FetchKeyAssets(assetCollection, new PHFetchOptions())
.Cast <PHAsset> ();
assets.AddRange(items);
}
private void UpdateFetchResults()
{
//What I do here is fetch both the albums list and the assets of each album.
//This way I have acces to the number of items in each album, I can load the 3
//thumbnails directly and I can pass the fetched result to the gridViewController.
_collectionsFetchResultsAssets = null;
_collectionsFetchResultsTitles = null;
//Fetch PHAssetCollections:
var topLevelUserCollections = _collectionsFetchResults[0];
var smartAlbums = _collectionsFetchResults[1];
// All album: Sorted by descending creation date.
var allFetchResults = new List <PHFetchResult>();
var allFetchResultLabels = new List <string> ();
var options = new PHFetchOptions {
Predicate = NSPredicate.FromFormat("mediaType in %@", ToNSArray(_picker.MediaTypes)),
SortDescriptors = new [] { new NSSortDescriptor("creationDate", _picker.GridSortOrder == SortOrder.Ascending) },
};
var assetsFetchResult = PHAsset.FetchAssets(options);
allFetchResults.Add(assetsFetchResult);
allFetchResultLabels.Add("picker.table.all-photos-label".Translate(defaultValue: "All photos"));
//User albums:
var userFetchResults = new List <PHFetchResult>();
var userFetchResultLabels = new List <string> ();
foreach (PHCollection collection in topLevelUserCollections)
{
if (collection is PHAssetCollection)
{
var collectionOptions = new PHFetchOptions {
Predicate = NSPredicate.FromFormat("mediaType in %@", ToNSArray(_picker.MediaTypes)),
SortDescriptors = new[] { new NSSortDescriptor("creationDate", _picker.GridSortOrder == SortOrder.Ascending) },
};
var assetCollection = (PHAssetCollection)collection;
//Albums collections are always PHAssetCollectionType=1 & PHAssetCollectionSubtype=2
var collectionAssetsFetchResult = PHAsset.FetchKeyAssets(assetCollection, collectionOptions);
userFetchResults.Add(collectionAssetsFetchResult);
userFetchResultLabels.Add(collection.LocalizedTitle);
}
}
//Smart albums: Sorted by descending creation date.
var smartFetchResults = new List <PHFetchResult>();
var smartFetchResultLabels = new List <string> ();
foreach (PHCollection collection in smartAlbums)
{
if (collection is PHAssetCollection)
{
var assetCollection = (PHAssetCollection)collection;
//Smart collections are PHAssetCollectionType=2;
if (_picker.CustomSmartCollections != null && _picker.CustomSmartCollections.Contains(assetCollection.AssetCollectionSubtype))
{
var smartFetchOptions = new PHFetchOptions {
Predicate = NSPredicate.FromFormat("mediaType in %@", ToNSArray(_picker.MediaTypes)),
SortDescriptors = new [] { new NSSortDescriptor("creationDate", _picker.GridSortOrder == SortOrder.Ascending) },
};
var smartAssetsFetchResult = PHAsset.FetchKeyAssets(assetCollection, smartFetchOptions);
if (smartAssetsFetchResult.Any())
{
smartFetchResults.Add(smartAssetsFetchResult);
smartFetchResultLabels.Add(collection.LocalizedTitle);
}
}
}
}
_collectionsFetchResultsAssets = new PHFetchResult[][] {
allFetchResults.ToArray(),
userFetchResults.ToArray(),
smartFetchResults.ToArray()
};
_collectionsFetchResultsTitles = new string[][] {
allFetchResultLabels.ToArray(),
userFetchResultLabels.ToArray(),
smartFetchResultLabels.ToArray()
};
}