概述
Photos.framework的常见功能包括：创建自定义相册、保存图片到自定义相册、搜索所有相册的图片。本文介绍该实现。
保存图片到相册
/**
* 保存图片到相册
*/
- (IBAction)saveImage {
PHAuthorizationStatus status = [PHPhotoLibrary authorizationStatus];
if (status == PHAuthorizationStatusDenied) {
NSLog(@"请到【设置-隐私-照片】打开访问开关");
} else if (status == PHAuthorizationStatusRestricted) {
NSLog(@"无法访问相册");
} else {
// 保存相片的标识
__block NSString *assetId = nil;
[[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{
// 保存相片到相机胶卷，并返回标识
assetId = [PHAssetCreationRequest creationRequestForAssetFromImage:[UIImage imageNamed:@"logo"]].placeholderForCreatedAsset.localIdentifier;
} completionHandler:^(BOOL success, NSError * _Nullable error) {
if (!success) {
NSLog(@"保存失败：%@", error);
return;
}
// 根据标识获得相片对象
PHAsset *asset = [PHAsset fetchAssetsWithLocalIdentifiers:@[assetId] options:nil].lastObject;
// 拿到自定义的相册对象
PHAssetCollection *collection = [self collection];
if (collection == nil) return;
// 保存相片到自定义相册中
[[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{
[[PHAssetCollectionChangeRequest changeRequestForAssetCollection:collection] addAssets:@[asset]];
} completionHandler:^(BOOL success, NSError * _Nullable error) {
if (success) {
NSLog(@"保存成功");
} else {
NSLog(@"保存失败：%@", error);
}
}];
}];
}
}
搜索所有相片
/** * 查询所有的图片 */- (IBAction)searchAllImages { // 遍历所有的自定义相册 PHFetchResult*collectionResult0 = [PHAssetCollection fetchAssetCollectionsWithType:PHAssetCollectionTypeAlbum subtype:PHAssetCollectionSubtypeAlbumRegular options:nil]; for (PHAssetCollection *collection in collectionResult0) { [self searchAllImagesInCollection:collection]; } // 获得相机胶卷的图片 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; }} /** * 查询某个相册里面的所有图片 */- (void)searchAllImagesInCollection:(PHAssetCollection *)collection{ // 采取同步获取图片（只获得一次图片） PHImageRequestOptions *imageOptions = [[PHImageRequestOptions alloc] init]; imageOptions.synchronous = YES; NSLog(@"相册名字：%@", collection.localizedTitle); // 遍历这个相册中的所有图片 PHFetchResult*assetResult = [PHAsset fetchAssetsInAssetCollection:collection options:nil];
for (PHAsset *asset in assetResult) {
// 过滤非图片
if (asset.mediaType != PHAssetMediaTypeImage) continue;
// 图片原尺寸
CGSize targetSize = CGSizeMake(asset.pixelWidth, asset.pixelHeight);
// 请求图片
[[PHImageManager defaultManager] requestImageForAsset:asset targetSize:targetSize contentMode:PHImageContentModeDefault options:imageOptions resultHandler:^(UIImage * _Nullable result, NSDictionary * _Nullable info) {
NSLog(@"图片：%@", result);
}];
}
