概述
Photos.framework的常見功能包括：創建自定義相冊、保存圖片到自定義相冊、搜索所有相冊的圖片。本文介紹該實現。
保存圖片到相冊
/**
* 保存圖片到相冊
*/
- (IBAction)saveImage {
PHAuthorizationStatus status = [PHPhotoLibrary authorizationStatus];
if (status == PHAuthorizationStatusDenied) {
NSLog(@"請到【設置-隱私-照片】打開訪問開關");
} else if (status == PHAuthorizationStatusRestricted) {
NSLog(@"無法訪問相冊");
} else {
// 保存相片的標識
__block NSString *assetId = nil;
[[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{
// 保存相片到相機膠卷，并返回標識
assetId = [PHAssetCreationRequest creationRequestForAssetFromImage:[UIImage imageNamed:@"logo"]].placeholderForCreatedAsset.localIdentifier;
} completionHandler:^(BOOL success, NSError * _Nullable error) {
if (!success) {
NSLog(@"保存失敗：%@", error);
return;
}
// 根據標識獲得相片對象
PHAsset *asset = [PHAsset fetchAssetsWithLocalIdentifiers:@[assetId] options:nil].lastObject;
// 拿到自定義的相冊對象
PHAssetCollection *collection = [self collection];
if (collection == nil) return;
// 保存相片到自定義相冊中
[[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{
[[PHAssetCollectionChangeRequest changeRequestForAssetCollection:collection] addAssets:@[asset]];
} completionHandler:^(BOOL success, NSError * _Nullable error) {
if (success) {
NSLog(@"保存成功");
} else {
NSLog(@"保存失敗：%@", error);
}
}];
}];
}
}
搜索所有相片
/** * 查詢所有的圖片 */- (IBAction)searchAllImages {? ? ? ? ? ? // 遍歷所有的自定義相冊? ? PHFetchResult*collectionResult0 = [PHAssetCollection fetchAssetCollectionsWithType:PHAssetCollectionTypeAlbum subtype:PHAssetCollectionSubtypeAlbumRegular options:nil];? ? for (PHAssetCollection *collection in collectionResult0) {? ? ? ? [self searchAllImagesInCollection:collection];? ? }? ? ? ? ? ? // 獲得相機膠卷的圖片? ? PHFetchResult*collectionResult1 = [PHAssetCollection fetchAssetCollectionsWithType:PHAssetCollectionTypeSmartAlbum subtype:PHAssetCollectionSubtypeAlbumRegular options:nil];? ? for (PHAssetCollection *collection in collectionResult1) {? ? ? ? if (![collection.localizedTitle isEqualToString:@"Camera Roll"]) continue;? ? ? ? [self searchAllImagesInCollection:collection];? ? ? ? break;? ? }}? ? /** * 查詢某個相冊里面的所有圖片 */- (void)searchAllImagesInCollection:(PHAssetCollection *)collection{? ? // 采取同步獲取圖片（只獲得一次圖片）? ? PHImageRequestOptions *imageOptions = [[PHImageRequestOptions alloc] init];? ? imageOptions.synchronous = YES;? ? ? ? ? ? NSLog(@"相冊名字：%@", collection.localizedTitle);? ? ? ? ? ? // 遍歷這個相冊中的所有圖片? ? PHFetchResult*assetResult = [PHAsset fetchAssetsInAssetCollection:collection options:nil];
for (PHAsset *asset in assetResult) {
// 過濾非圖片
if (asset.mediaType != PHAssetMediaTypeImage) continue;
// 圖片原尺寸
CGSize targetSize = CGSizeMake(asset.pixelWidth, asset.pixelHeight);
// 請求圖片
[[PHImageManager defaultManager] requestImageForAsset:asset targetSize:targetSize contentMode:PHImageContentModeDefault options:imageOptions resultHandler:^(UIImage * _Nullable result, NSDictionary * _Nullable info) {
NSLog(@"圖片：%@", result);
}];
}
