iOS功能 - 将图片或视图存入相册

将图片或视图存入相册

1 - 准备工作：配置 Info.plist 文件

 <key>NSPhotoLibraryUsageDescription</key>
 <string>需要您的同意，才能访问您的媒体资料库</string>

 <key>NSPhotoLibraryAddUsageDescription</key>
 <string>需要您的同意，才能访问您的媒体资料库</string>

2 - 代码示例

#import "ViewController.h"
#import <Photos/Photos.h> // 引入文件
@interface ViewController()

@property(nonatomic,strong)UIImageView *testView; // 将要保存的图片
@property(nonatomic,strong)PHAssetCollection *createCollection;// 相册

@end


@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];

    // btn
    UIButton *nextBT = [UIButton buttonWithType:UIButtonTypeCustom];
    nextBT.frame = CGRectMake(60, 30, self.view.frame.size.width - 120, 40);
    [nextBT setTitleColor:[UIColor redColor] forState:UIControlStateNormal];
    [nextBT setTitleColor:[UIColor blackColor] forState:UIControlStateHighlighted];
    [nextBT setTitle:@"存储测试" forState:UIControlStateNormal];
    nextBT.layer.cornerRadius = 8;
    nextBT.layer.masksToBounds  =  YES;
    nextBT.backgroundColor = [UIColor cyanColor];
    [nextBT addTarget:self action:@selector(saveView) forControlEvents:UIControlEventTouchUpInside];// 存储照片
    [self.view addSubview:nextBT];

    // 图片
    self.testView = [[UIImageView alloc] init];
    self.testView.backgroundColor = [UIColor redColor];
    self.testView.frame = CGRectMake((self.view.frame.size.width - 200)/2.0, 120, 200, 300);
    [self.view addSubview:self.testView];

}


// 将图片保存到系统相册
-(void)saveView{

    UIImageWriteToSavedPhotosAlbum(self.testView.image, self, @selector(image:didFinishSavingWithError:contextInfo:), nil);
}

-(void)image:(UIImage *)image didFinishSavingWithError:(NSError *)error contextInfo:(void *)contextInfo {

    NSString *msg = nil ;
    if(error){
        msg = @"保存图片失败" ;
    }else{
        msg = @"保存图片成功" ;
    }
    NSLog(@"%@",msg);
}


// 将图片保存到系统相册： 使用 Photos 框架
-(void)saveViewII{

    // 凡是涉及增删改的操作，均需要放在 performChanges 里面执行
    [[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{
        
        [PHAssetChangeRequest creationRequestForAssetFromImage:[self.testView image]];
    } completionHandler:^(BOOL success, NSError * _Nullable error) {
        
        if (error) {
            NSLog(@"%@",@"保存失败");
        } else {
            NSLog(@"%@",@"保存成功");
        }
    }];

}

//-------------------------------------------------------------------------------

// 将 View 存入相册
-(void)saveViewsInAnAlbum{

    NSError *error = nil;
    __block PHObjectPlaceholder *placeholder = nil;

    // 把 View  转换成 image 进行保存
    CGSize s = self.view.bounds.size;
    UIGraphicsBeginImageContextWithOptions(s, NO, [UIScreen mainScreen].scale);
    [self.view.layer renderInContext:UIGraphicsGetCurrentContext()];
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    [[PHPhotoLibrary sharedPhotoLibrary] performChangesAndWait:^{
        placeholder =  [PHAssetChangeRequest creationRequestForAssetFromImage:image].placeholderForCreatedAsset;
    } error:&error];

    if (error) {
        NSLog(@"view 保存失败");
    }else {
        NSLog(@"view 保存成功");
    }
}

//-------------------------------------------------------------------------------

// 将图片保存图片到自定义相册
-(void)movePicToMyAlbum{

    NSError *error = nil;
    __block PHObjectPlaceholder *placeholder = nil;
    
    [[PHPhotoLibrary sharedPhotoLibrary] performChangesAndWait:^{
        
        placeholder =  [PHAssetChangeRequest creationRequestForAssetFromImage:self.testView.image].placeholderForCreatedAsset;
    } error:&error];
    
    if (error) {
        
        NSLog(@"保存失败");
        return;
    }

    // 搞一个相册
    PHAssetCollection * assetCollection = [self createAlbumII];
    if (assetCollection == nil) {
        NSLog(@"创建相册失败");
        return;
    }

    // 方式 ①：将刚才保存到系统相册里面的图片转存到自定义相册，最新保存的图片排在最后面
    [[PHPhotoLibrary sharedPhotoLibrary]performChangesAndWait:^{
        
        PHAssetCollectionChangeRequest *requtes = [PHAssetCollectionChangeRequest changeRequestForAssetCollection:assetCollection];
        [requtes addAssets:@[placeholder]];
    } error:&error];

//    // 方式 ②：最新保存的图片排在最前面
//    [[PHPhotoLibrary sharedPhotoLibrary] performChangesAndWait:^{
//
//        PHAssetCollectionChangeRequest *requtes = [PHAssetCollectionChangeRequest changeRequestForAssetCollection:assetCollection];
//        [requtes insertAssets:@[placeholder] atIndexes:[NSIndexSet indexSetWithIndex:0]];
//    } error:&error];

    if (error) {
        NSLog(@"保存图片失败");
    } else {
        NSLog(@"保存图片成功");
    }
}

// 创建自定义相册
// 造成问题：如果我们一直点击保存图片按钮，则会重复创建多个相册，如何解决？参见 createAlbumII 方法
-(void)createAlbum{

    [[PHPhotoLibrary sharedPhotoLibrary] performChangesAndWait:^{

        // 获取 app 名字，用作相册名
        NSString *title = [NSBundle mainBundle].infoDictionary[(__bridge NSString*)kCFBundleNameKey];
        // 创建相册
        [PHAssetCollectionChangeRequest creationRequestForAssetCollectionWithTitle:title];
    } error:nil];

}

// 避免重复创建一个相册
-(PHAssetCollection*)createAlbumII{

    NSString *title = [NSBundle mainBundle].infoDictionary[(__bridge NSString*)kCFBundleNameKey];
    // 查询所有自定义相册
    PHFetchResult<PHAssetCollection *> *collections = [PHAssetCollection fetchAssetCollectionsWithType:PHAssetCollectionTypeAlbum subtype:PHAssetCollectionSubtypeAlbumRegular options:nil];

    self.createCollection = nil;
    for (PHAssetCollection *collection in collections) {

        if ([collection.localizedTitle isEqualToString:title]) {
            self.createCollection = collection;
            break;
        }
    }

    // 相册没有被创建
    if (self.createCollection == nil) {

        NSError *error = nil;

//        // 方式 ①：创建相册
//        [[PHPhotoLibrary sharedPhotoLibrary]performChangesAndWait:^{
//
//            [PHAssetCollectionChangeRequest creationRequestForAssetCollectionWithTitle:title];// 创建相册
//        } error:&error];

        // 方式 ②（推荐）：创建相册
        __block NSString *createCollectionID = nil;
        [[PHPhotoLibrary sharedPhotoLibrary] performChangesAndWait:^{
            createCollectionID = [PHAssetCollectionChangeRequest creationRequestForAssetCollectionWithTitle:title].placeholderForCreatedAssetCollection.localIdentifier;
        } error:&error];

        self.createCollection = [PHAssetCollection fetchAssetCollectionsWithLocalIdentifiers:@[createCollectionID] options:nil].firstObject;
    }

    return _createCollection;
}


@end