将照片保存到iOS 8中的自定义相册

Question

我在这里需要一些帮助,我有一个方法可以在iOS 8中将UIImage保存到相机胶卷而没有问题.方法如下

[[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{
    [PHAssetChangeRequest creationRequestForAssetFromImage:image];
}completionHandler:^(BOOL success, NSError *error) {
    if(success){
        NSLog(@"worked");
    }else{
        NSLog(@"Error: %@", error);

    }
}];

我需要调整该代码,以便图像而不是将UIImage保存到相机胶卷,它保存到名为"MyAlbum"的自定义相册

我正在使用Photos.framework

Answer 1

您首先需要检查相册是否存在获取请求,然后将图像添加到相册或创建相册,然后添加图像.

#import <Photos/Photos.h>

- (void)addImageToCameraRoll:(UIImage *)image {
    NSString *albumName = @"MyAlbum";

    void (^saveBlock)(PHAssetCollection *assetCollection) = ^void(PHAssetCollection *assetCollection) {
        [[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{
            PHAssetChangeRequest *assetChangeRequest = [PHAssetChangeRequest creationRequestForAssetFromImage:image];
            PHAssetCollectionChangeRequest *assetCollectionChangeRequest = [PHAssetCollectionChangeRequest changeRequestForAssetCollection:assetCollection];
            [assetCollectionChangeRequest addAssets:@[[assetChangeRequest placeholderForCreatedAsset]]];

        } completionHandler:^(BOOL success, NSError *error) {
            if (!success) {
                NSLog(@"Error creating asset: %@", error);
            }
        }];
    };

    PHFetchOptions *fetchOptions = [[PHFetchOptions alloc] init];
    fetchOptions.predicate = [NSPredicate predicateWithFormat:@"localizedTitle = %@", albumName];
    PHFetchResult *fetchResult = [PHAssetCollection fetchAssetCollectionsWithType:PHAssetCollectionTypeAlbum subtype:PHAssetCollectionSubtypeAny options:fetchOptions];
    if (fetchResult.count > 0) {
        saveBlock(fetchResult.firstObject);
    } else {
        __block PHObjectPlaceholder *albumPlaceholder;
        [[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{
            PHAssetCollectionChangeRequest *changeRequest = [PHAssetCollectionChangeRequest creationRequestForAssetCollectionWithTitle:albumName];
            albumPlaceholder = changeRequest.placeholderForCreatedAssetCollection;

        } completionHandler:^(BOOL success, NSError *error) {
            if (success) {
                PHFetchResult *fetchResult = [PHAssetCollection fetchAssetCollectionsWithLocalIdentifiers:@[albumPlaceholder.localIdentifier] options:nil];
                if (fetchResult.count > 0) {
                    saveBlock(fetchResult.firstObject);
                }
            } else {
                NSLog(@"Error creating album: %@", error);
            }
        }];
    }
}

Answer 2

在将资源添加到相册之前,创建名为"MyAlbum"的新相册.

    // Create new album.
    __block PHObjectPlaceholder *albumPlaceholder;
    [[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{
        PHAssetCollectionChangeRequest *changeRequest = [PHAssetCollectionChangeRequest creationRequestForAssetCollectionWithTitle:title];
        albumPlaceholder = changeRequest.placeholderForCreatedAssetCollection;
    } completionHandler:^(BOOL success, NSError *error) {
        if (success) {
            PHFetchResult *fetchResult = [PHAssetCollection fetchAssetCollectionsWithLocalIdentifiers:@[albumPlaceholder.localIdentifier] options:nil];
            PHAssetCollection *assetCollection = fetchResult.firstObject;

            // Add it to the photo library
            [[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{
                PHAssetChangeRequest *assetChangeRequest = [PHAssetChangeRequest creationRequestForAssetFromImage:image];

                PHAssetCollectionChangeRequest *assetCollectionChangeRequest = [PHAssetCollectionChangeRequest changeRequestForAssetCollection:assetCollection];
                [assetCollectionChangeRequest addAssets:@[[assetChangeRequest placeholderForCreatedAsset]]];
            } completionHandler:^(BOOL success, NSError *error) {
                if (!success) {
                    NSLog(@"Error creating asset: %@", error);
                }
            }];
        } else {
            NSLog(@"Error creating album: %@", error);
        }
    }];

Answer 3

在执行更改块中，指定请求的 assetCollection

let request = PHAssetCollectionChangeRequest.creationRequestForAssetCollectionWithTitle(-YOUR ALBUM NAME-)