iOS 保存图片到相册

原创

wx646209fa8f818 2023-05-15 23:16:11 博主文章分类：iOS ©著作权

文章标签 子视图自定义控件 文章分类 JavaScript 前端开发

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开发步骤

给UIImageView添加一个点击手势，点击弹出图片控制器
图片控制器中的子视图包括UIScrollView、一个返回按钮、一个保存按钮
保存图片到【相机胶卷】中

C语言函数：UIImageWriteToSavedPhotosAlbum
AssetsLibrary框架
Photos框架

自定义一个相册，相册名字一般为应用的名称

AssetsLibrary框架
Photos框架

将【相机胶卷】中的保存的图片的引用添加到【自定义相册】中

AssetsLibrary框架
Photos框架

具体开发步骤

- (void)saveClick {
    // 获取授权状态
    PHAuthorizationStatus oldStatus = [PHPhotoLibrary authorizationStatus];

    // 如果用户还没有做出选择，该方法会弹出授权，如果用户做出了选择就执行代码块中的代码
    [PHPhotoLibrary requestAuthorization:^(PHAuthorizationStatus status) {
        dispatch_async(dispatch_get_main_queue(), ^{
            if (status == PHAuthorizationStatusDenied) {
                //
                if (oldStatus != PHAuthorizationStatusNotDetermined) {
                    [SVProgressHUD showWithStatus:@"打开开关"];
                }
            } else if (status == PHAuthorizationStatusAuthorized) {
                [self savePhotoToAppAlbum];
            } else if (status == PHAuthorizationStatusRestricted) {
                [SVProgressHUD showErrorWithStatus:@"因系统原因，无法访问相册!"];
            }
        });
    }];
}

// 保存图片到自定义的App相册中
- (void)savePhotoToAppAlbum {
    // 1. 将图片保存到[相机胶卷]相册中
    PHFetchResult<PHAsset *> *createdAssets = [self createAssets];
    if (createdAssets == nil) {
        [SVProgressHUD showErrorWithStatus:@"保存图片失败"];
        return;
    }

    // 2. 创建自定义相册
    PHAssetCollection *createdCollection = [self createCollection];
    if (createdCollection == nil) {
        [SVProgressHUD showErrorWithStatus:@"创建相册失败"];
        return;
    }

    // 3. 将图片添加到自定义的相册中
    NSError *error = nil;
    [[PHPhotoLibrary sharedPhotoLibrary] performChangesAndWait:^{
        PHAssetCollectionChangeRequest *request = [PHAssetCollectionChangeRequest changeRequestForAssetCollection:createdCollection];
        [request insertAssets:createdAssets atIndexes:[NSIndexSet indexSetWithIndex:0]];
    } error:&error];

    if (error == nil) {
        [SVProgressHUD showSuccessWithStatus:@"保存成功!"];
    } else {
        [SVProgressHUD showErrorWithStatus:@"保存失败!"];
    }
}


// 保存相册到【相机胶卷】中，并返回保存的图片
- (PHFetchResult<PHAsset *> *)createAssets {
    NSError *error = nil;
    __block NSString *assetID = nil;

    // 保存相册到【相机胶卷】中
    [[PHPhotoLibrary sharedPhotoLibrary] performChangesAndWait:^{
        assetID = [PHAssetChangeRequest creationRequestForAssetFromImage:self.imageView.image].placeholderForCreatedAsset.localIdentifier;
    } error:&error];

    if (error != nil) return nil;

    return [PHAsset fetchAssetsWithLocalIdentifiers:@[assetID] options:nil];
}

// 创建相册
- (PHAssetCollection *)createCollection {
    // 相册标题
    NSString *title = [NSBundle mainBundle].infoDictionary[(__bridge NSString *)kCFBundleNameKey];

    // 判断是否已经创建过该相册,创建则返回，否则创建新的相册
    PHFetchResult<PHAssetCollection *> *collections = [PHAssetCollection fetchAssetCollectionsWithType:PHAssetCollectionTypeAlbum subtype:PHAssetCollectionSubtypeAlbumRegular options:nil];
    for (PHAssetCollection *collection in collections) {
        if ([collection.localIdentifier isEqualToString:title]) {
            return collection;
        }
    }

    NSError *error = nil;
    __block NSString *createdCollectionID = nil;
    [[PHPhotoLibrary sharedPhotoLibrary] performChangesAndWait:^{
        createdCollectionID = [PHAssetCollectionChangeRequest creationRequestForAssetCollectionWithTitle:title].placeholderForCreatedAssetCollection.localIdentifier;
    } error:&error];

    if (error != nil) return nil;

    return [PHAssetCollection fetchAssetCollectionsWithLocalIdentifiers:@[createdCollectionID] options:nil].firstObject;
}