图库中创建自己的相册并存储图片、视频等

导入库Photos

1，首先请求权限：

    
-(void)requestAuthorization {
    
    [PHPhotoLibrary requestAuthorization:^(PHAuthorizationStatus status) {
        //用户同意则开始创建。不同意弹出提示
        if (status ==  PHAuthorizationStatusAuthorized) {
            
            [self createFolder];
            
        }  else {
            
            UIAlertController *alert = [UIAlertController alertControllerWithTitle:@"App无法访问你的媒体资料库" message:@"app无法正常使用，现在去设置？" preferredStyle:UIAlertControllerStyleAlert];
            
            UIAlertAction *actionCancel = [UIAlertAction actionWithTitle:@"取消" style:UIAlertActionStyleCancel handler:^(UIAlertAction * _Nonnull action) {
                
            }];
            [alert addAction:actionCancel];
            
            UIAlertAction *actionOK = [UIAlertAction actionWithTitle:@"设置" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
                
                NSURL * url = [NSURL  URLWithString: UIApplicationOpenSettingsURLString];
                
                if ( [[UIApplication sharedApplication] canOpenURL: url] ) {
                    
                    NSURL*url = [NSURL URLWithString:UIApplicationOpenSettingsURLString];
                    [[UIApplication sharedApplication] openURL:url];
                    
                }
                
            }];
            
            [alert addAction:actionOK];
            
            dispatch_async(dispatch_get_main_queue(), ^{
                
                [self presentViewController:alert animated:YES completion:nil];
                
            });
            
        }
    }];
}

2，创建

由于相册名字用户是可以更改的，所以创建成功后应将相册的localIdentifier存储在本地，以便判断读取 。

- (void)createFolder {
    
    if(GetAlbumID) {
        
        return;
    }
    
    __block  NSString *localIdentifier = nil;
    
    [[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{
        
        PHAssetCollectionChangeRequest *req =  [PHAssetCollectionChangeRequest creationRequestForAssetCollectionWithTitle:VideoAlbumName];
        localIdentifier =  req.placeholderForCreatedAssetCollection.localIdentifier;
        
    } completionHandler:^(BOOL success, NSError * _Nullable error) {
        
        if (success) {
            
            NSLog(@"创建相册文件夹成功!");
            
            if (localIdentifier) {
                
                [[NSUserDefaults standardUserDefaults] setObject:localIdentifier forKey:@"AlbumID"];
            }
            
            
        } else {
            NSLog(@"创建相册文件夹失败:%@", error);
        }
    }];
}

3，保存

+(void)save:(NSURL *)url finish:(SaveAlbumFinish)saveAlbumFinish {
    
    __block BOOL isHaveAlbum = NO;
    //首先获取相册的集合
    PHFetchResult *collectonResuts = [PHCollectionList fetchTopLevelUserCollectionsWithOptions:nil];
    //对获取到集合进行遍历
    [collectonResuts enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
        PHAssetCollection *assetCollection = obj;
        //根据GetAlbumID判断是否是我们要写入照片的相册
        if ([assetCollection.localIdentifier isEqualToString:GetAlbumID])  {
            
            isHaveAlbum = YES;
            
            [[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{
                //请求创建一个Asset
                PHAssetChangeRequest *assetRequest = [PHAssetChangeRequest creationRequestForAssetFromVideoAtFileURL:url];
                //请求编辑相册
                PHAssetCollectionChangeRequest *collectonRequest = [PHAssetCollectionChangeRequest changeRequestForAssetCollection:assetCollection];
                //为Asset创建一个占位符，放到相册编辑请求中
                PHObjectPlaceholder *placeHolder = [assetRequest placeholderForCreatedAsset];
                //相册中添加视频
                [collectonRequest addAssets:@[placeHolder]];
                
            } completionHandler:^(BOOL success, NSError *error) {
                
                dispatch_async(dispatch_get_main_queue(), ^{
                   
                    if (saveAlbumFinish) {
                        
                        saveAlbumFinish(success, error);
                    }
                    
                });
            }];
        }
    }];
    
    //没有读取到待存储的相册 
    if (!isHaveAlbum) {
        
        if (saveAlbumFinish) {
        
            saveAlbumFinish(NO, [NSError errorWithDomain:@"没有相册" code:0 userInfo: nil]);
        }
    }
}