iOS系统相册基本操作

作者: 跑调的安眠曲 | 来源:发表于2016-05-09 23:53 被阅读3807次

一、前言####

在iOS8以前，我们操作系统相册，一般使用<AssetsLibrary/AssetsLibrary.h>库进行操作，iOS8以后，Apple推出了<Photos/Photos.h>库，以提升操作系统相册的效率。针对目前iOS8及以上用户占有率已超过95%，本文将采用<Photos/Photos.h>库进行开发说明。

二、针对系统相册的操作####

思路：为了满足保存视频/图片到系统相册指定路径，并随时准备删除的变态需求，首先得弄清<Photos/Photos.h>库，保存一般都好说，但是想删除系统相册中的某个图片或者视频，第一印象就根据保存的文件名来进行删除，可是使用过该api之后，发现存在系统相册之后的名字根本就不是你原来存的那个名字，fileName也没有对外提供给你使用，但是它提供了localIdentifier字段，用来唯一标识系统相册中的元素，那么事情就好办了，我们在进行保存图片或者视频的时候，将其localIdentifier缓存到一个plist文件中，然后每次删除的时候，通过对应的文件名找到相应的localIdentifier就可以进行删除了。

判断系统相册中是否存在该指定的文件夹

- (BOOL)isExistFolder:(NSString *)folderName {
    //首先获取用户手动创建相册的集合
    PHFetchResult *collectonResuts = [PHCollectionList fetchTopLevelUserCollectionsWithOptions:nil];
    
    __block BOOL isExisted = NO;
    //对获取到集合进行遍历
    [collectonResuts enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
        PHAssetCollection *assetCollection = obj;
        //folderName是我们写入照片的相册
        if ([assetCollection.localizedTitle isEqualToString:folderName])  {
            isExisted = YES;
        }
    }];
    
    return isExisted;
}

在系统相册中创建指定的文件夹

- (void)createFolder:(NSString *)folderName {
    if (![self isExistFolder:folderName]) {
        [[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{
            //添加HUD文件夹
            [PHAssetCollectionChangeRequest creationRequestForAssetCollectionWithTitle:folderName];
            
        } completionHandler:^(BOOL success, NSError * _Nullable error) {
            if (success) {
                NSLog(@"创建相册文件夹成功!");
            } else {
                NSLog(@"创建相册文件夹失败:%@", error);
            }
        }];
    }
}

- (void)saveImagePath:(NSString *)imagePath{
    NSURL *url = [NSURL fileURLWithPath:imagePath];
    
    //标识保存到系统相册中的标识
    __block NSString *localIdentifier;
    
    //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;
        //Camera Roll是我们写入照片的相册
        if ([assetCollection.localizedTitle isEqualToString:_folderName])  {
            [[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{
                //请求创建一个Asset
                PHAssetChangeRequest *assetRequest = [PHAssetChangeRequest creationRequestForAssetFromImageAtFileURL: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];
                //相册中添加照片
                [collectonRequest addAssets:@[placeHolder]];
                
                localIdentifier = placeHolder.localIdentifier;
            } completionHandler:^(BOOL success, NSError *error) {
                if (success) {
                    NSLog(@"保存图片成功!");
                    NSMutableDictionary *dict = [NSMutableDictionary dictionaryWithDictionary:[self readFromPlist]];
                    [dict setObject:localIdentifier forKey:[self showFileNameFromPath:imagePath]];
                    [self writeDicToPlist:dict];
                } else {
                    NSLog(@"保存图片失败:%@", error);
                }
            }];
        }
    }];
}


- (void)saveVideoPath:(NSString *)videoPath {
    NSURL *url = [NSURL fileURLWithPath:videoPath];
    
    //标识保存到系统相册中的标识
    __block NSString *localIdentifier;
    
    //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;
        //folderName是我们写入照片的相册
        if ([assetCollection.localizedTitle isEqualToString:_folderName])  {
            [[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]];
                
                localIdentifier = placeHolder.localIdentifier;
            } completionHandler:^(BOOL success, NSError *error) {
                if (success) {
                    NSLog(@"保存视频成功!");
                    NSMutableDictionary *dict = [NSMutableDictionary dictionaryWithDictionary:[self readFromPlist]];
                    [dict setObject:localIdentifier forKey:[self showFileNameFromPath:videoPath]];
                    [self writeDicToPlist:dict];
                } else {
                    NSLog(@"保存视频失败:%@", error);
                }
            }];
        }
    }];
}

- (void)deleteFile:(NSString *)filePath {
    if ([self isExistFolder:_folderName]) {
        //获取需要删除文件的localIdentifier
        NSDictionary *dict = [self readFromPlist];
        NSString *localIdentifier = [dict valueForKey:[self showFileNameFromPath:filePath]];
        
        PHFetchResult *collectonResuts = [PHCollectionList fetchTopLevelUserCollectionsWithOptions:nil];
        [collectonResuts enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
            PHAssetCollection *assetCollection = obj;
            if ([assetCollection.localizedTitle isEqualToString:_folderName])  {
                PHFetchResult *assetResult = [PHAsset fetchAssetsInAssetCollection:assetCollection options:[PHFetchOptions new]];
                [assetResult enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
                    PHAsset *asset = obj;
                    if ([localIdentifier isEqualToString:asset.localIdentifier]) {
                        [[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{
                            [PHAssetChangeRequest deleteAssets:@[obj]];
                        } completionHandler:^(BOOL success, NSError *error) {
                            if (success) {
                                NSLog(@"删除成功!");
                                NSMutableDictionary *updateDic = [NSMutableDictionary dictionaryWithDictionary:dict];
                                [updateDic removeObjectForKey:[self showFileNameFromPath:filePath]];
                                [self writeDicToPlist:updateDic];
                            } else {
                                NSLog(@"删除失败:%@", error);
                            }
                        }];
                    }
                }];
            }
        }];
    }
}

下面给出具体的实现代码：######

头文件定义如下：

#import <Foundation/Foundation.h>

@interface YQAssetOperator : NSObject

/**
 *  初始化方法
 *
 *  @param folderName 操作的目录文件
 *
 *  @return 操作对象
 */
- (instancetype)initWithFolderName:(NSString *)folderName;

/**
 *  保存图片到系统相册
 *
 *  @param imagePath  保存的图片路径
 *  @param folderName 目的文件的路径
 */
- (void)saveImagePath:(NSString *)imagePath;

/**
 *  保存视频到系统相册
 *
 *  @param videoPath  保存的视频路径
 *  @param folderName 目的文件的路径
 */
- (void)saveVideoPath:(NSString *)videoPath;

/**
 *  删除系统相册中的文件
 *
 *  @param filePath   文件的路径
 *  @param folderName 文件夹的名字
 */
- (void)deleteFile:(NSString *)filePath;

@end

实现文件：

#import "YQAssetOperator.h"
#import <Photos/Photos.h>

@interface YQAssetOperator ()

@property (nonatomic, copy) NSString *plistName;
@property (nonatomic, copy) NSString *folderName;

@end

@implementation YQAssetOperator

- (instancetype)initWithFolderName:(NSString *)folderName {
    self = [self init];
    if (self) {
        self.plistName = @"Asset";
        self.folderName = folderName;
    }
    return self;
}

- (void)saveImagePath:(NSString *)imagePath{
    NSURL *url = [NSURL fileURLWithPath:imagePath];
    
    //标识保存到系统相册中的标识
    __block NSString *localIdentifier;
    
    //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;
        //Camera Roll是我们写入照片的相册
        if ([assetCollection.localizedTitle isEqualToString:_folderName])  {
            [[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{
                //请求创建一个Asset
                PHAssetChangeRequest *assetRequest = [PHAssetChangeRequest creationRequestForAssetFromImageAtFileURL: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];
                //相册中添加照片
                [collectonRequest addAssets:@[placeHolder]];
                
                localIdentifier = placeHolder.localIdentifier;
            } completionHandler:^(BOOL success, NSError *error) {
                if (success) {
                    NSLog(@"保存图片成功!");
                    NSMutableDictionary *dict = [NSMutableDictionary dictionaryWithDictionary:[self readFromPlist]];
                    [dict setObject:localIdentifier forKey:[self showFileNameFromPath:imagePath]];
                    [self writeDicToPlist:dict];
                } else {
                    NSLog(@"保存图片失败:%@", error);
                }
            }];
        }
    }];
}

- (void)saveVideoPath:(NSString *)videoPath {
    NSURL *url = [NSURL fileURLWithPath:videoPath];
    
    //标识保存到系统相册中的标识
    __block NSString *localIdentifier;
    
    //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;
        //folderName是我们写入照片的相册
        if ([assetCollection.localizedTitle isEqualToString:_folderName])  {
            [[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]];
                
                localIdentifier = placeHolder.localIdentifier;
            } completionHandler:^(BOOL success, NSError *error) {
                if (success) {
                    NSLog(@"保存视频成功!");
                    NSMutableDictionary *dict = [NSMutableDictionary dictionaryWithDictionary:[self readFromPlist]];
                    [dict setObject:localIdentifier forKey:[self showFileNameFromPath:videoPath]];
                    [self writeDicToPlist:dict];
                } else {
                    NSLog(@"保存视频失败:%@", error);
                }
            }];
        }
    }];
}

- (void)deleteFile:(NSString *)filePath {
    if ([self isExistFolder:_folderName]) {
        //获取需要删除文件的localIdentifier
        NSDictionary *dict = [self readFromPlist];
        NSString *localIdentifier = [dict valueForKey:[self showFileNameFromPath:filePath]];
        
        PHFetchResult *collectonResuts = [PHCollectionList fetchTopLevelUserCollectionsWithOptions:nil];
        [collectonResuts enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
            PHAssetCollection *assetCollection = obj;
            if ([assetCollection.localizedTitle isEqualToString:_folderName])  {
                PHFetchResult *assetResult = [PHAsset fetchAssetsInAssetCollection:assetCollection options:[PHFetchOptions new]];
                [assetResult enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
                    PHAsset *asset = obj;
                    if ([localIdentifier isEqualToString:asset.localIdentifier]) {
                        [[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{
                            [PHAssetChangeRequest deleteAssets:@[obj]];
                        } completionHandler:^(BOOL success, NSError *error) {
                            if (success) {
                                NSLog(@"删除成功!");
                                NSMutableDictionary *updateDic = [NSMutableDictionary dictionaryWithDictionary:dict];
                                [updateDic removeObjectForKey:[self showFileNameFromPath:filePath]];
                                [self writeDicToPlist:updateDic];
                            } else {
                                NSLog(@"删除失败:%@", error);
                            }
                        }];
                    }
                }];
            }
        }];
    }
    
}

- (BOOL)isExistFolder:(NSString *)folderName {
    //首先获取用户手动创建相册的集合
    PHFetchResult *collectonResuts = [PHCollectionList fetchTopLevelUserCollectionsWithOptions:nil];
    
    __block BOOL isExisted = NO;
    //对获取到集合进行遍历
    [collectonResuts enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
        PHAssetCollection *assetCollection = obj;
        //folderName是我们写入照片的相册
        if ([assetCollection.localizedTitle isEqualToString:folderName])  {
            isExisted = YES;
        }
    }];
    
    return isExisted;
}

- (void)createFolder:(NSString *)folderName {
    if (![self isExistFolder:folderName]) {
        [[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{
            //添加HUD文件夹
            [PHAssetCollectionChangeRequest creationRequestForAssetCollectionWithTitle:folderName];
            
        } completionHandler:^(BOOL success, NSError * _Nullable error) {
            if (success) {
                NSLog(@"创建相册文件夹成功!");
            } else {
                NSLog(@"创建相册文件夹失败:%@", error);
            }
        }];
    }
}

#pragma mark - setters和getters
- (void)setFolderName:(NSString *)folderName {
    if (!_folderName) {
        _folderName = folderName;
        [self createFolder:folderName];
    }
}

- (void)setPlistName:(NSString *)plistName {
    if (!_plistName) {
        _plistName = plistName;
        
        //创建plist文件，记录path和localIdentifier的对应关系
        NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask,YES);
        NSString *path = [paths objectAtIndex:0];
        NSString *filePath = [path stringByAppendingPathComponent:[NSString stringWithFormat:@"%@.plist", plistName]];
        NSLog(@"plist路径:%@", filePath);
        NSFileManager* fm = [NSFileManager defaultManager];
        if (![fm fileExistsAtPath:filePath]) {
            BOOL success = [fm createFileAtPath:filePath contents:nil attributes:nil];
            if (!success) {
                NSLog(@"创建plist文件失败!");
            } else {
                NSLog(@"创建plist文件成功!");
            }
        } else {
            NSLog(@"沙盒中已有该plist文件，无需创建!");
        }
    }
}

#pragma mark - 写入plist文件
- (void)writeDicToPlist:(NSDictionary *)dict {
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask,YES);
    NSString *path = [paths objectAtIndex:0];
    NSString *filePath = [path stringByAppendingPathComponent:[NSString stringWithFormat:@"%@.plist", _plistName]];
    [dict writeToFile:filePath atomically:YES];
}

#pragma mark - 读取plist文件
- (NSDictionary *)readFromPlist {
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask,YES);
    NSString *path = [paths objectAtIndex:0];
    NSString *filePath = [path stringByAppendingPathComponent:[NSString stringWithFormat:@"%@.plist", _plistName]];
    return [NSDictionary dictionaryWithContentsOfFile:filePath];
}

#pragma mark - 根据路径获取文件名
- (NSString *)showFileNameFromPath:(NSString *)path {
    return [NSString stringWithFormat:@"%@", [[path componentsSeparatedByString:@"/"] lastObject]];
}

@end

测试程序：

#import "ViewController.h"
#import "YQAssetOperator.h"

@interface ViewController (){
    YQAssetOperator *_assetOperator;
}

- (IBAction)deleteFile:(UIButton *)sender;
- (IBAction)addFiles:(UIButton *)sender;

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    self.view.backgroundColor = [UIColor grayColor];
    _assetOperator = [[YQAssetOperator alloc] initWithFolderName:@"LOVE"];
    
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

- (IBAction)deleteFile:(UIButton *)sender {
    NSString *videoPath =[[NSBundle mainBundle] pathForResource:@"0425_103546" ofType:@"mp4"];
    [_assetOperator deleteFile:videoPath];
}

- (IBAction)addFiles:(UIButton *)sender {
    //保存图片
    NSString *imagePath =[[NSBundle mainBundle] pathForResource:@"scanner" ofType:@"png"];
    [_assetOperator saveImagePath:imagePath];
    
    //保存视频
    NSString *videoPath =[[NSBundle mainBundle] pathForResource:@"0425_103546" ofType:@"mp4"];
    [_assetOperator saveVideoPath:videoPath];
}

@end

测试程序将一个二维码图片和一段视频存入了"LOVE"文件夹中，效果图如下：

效果图

源码地址：https://github.com/GitterYang/YQSystemPhotoOperation

如有什么疑问或者文中有不当之处，请指出，谢谢。祝大家好梦！

网友评论

Happy晓哥:楼主,没有在info.plist 加上获取相机和相册的权限,所以运行就报错.加上就好了
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<string>App需要您的同意,才能访问相册</string>
</plist>

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<string>App需要您的同意,才能访问相机</string>
</plist>
开局四带二:demo 下载真机运行报错，虚拟机运行，创建失败
开局四带二:@跑调的安眠曲我可以跑起来了现在有个问题，就是系统相册可以保存什么格式类型的文件呢？（我手头有个项目，要吧录音文件，存到系统相册文件下，不知道有没有办法？？）
跑调的安眠曲: 不是吧？什么错？
vision_colion:楼主，如果想要实现拍照存到自己建的相册是不是得先存本地
跑调的安眠曲:不用啊
风语随风:我用一个非png格式的文件改成png的保存到自定义相册实际上失败了，但是success那块输出成功，请问这个怎么解决？
岁月丿静好:请问获取自定义相册视频功能怎么写?
跑调的安眠曲:@岁月丿静好看产品怎么设计咯
3c6544ed9c85:请问可以不出现提示框直接删除吗？
7827ca403a04:请问一下，在app的documents 下放一个录制的视频，然后用上面的代码导到本地相册中，app中的文件还在不在呢？意思就是这个文件导出后是占了一份存储空间还是两份？
跑调的安眠曲:@OYHeaven 不行的
chinwy:请问提示框能不能修改?
42e1b2b337c4:@跑调的安眠曲打错了，是中文
42e1b2b337c4:@跑调的安眠曲能不能改弹出框上的语言，比如中午或者日文
跑调的安眠曲:@chinwy 你想怎么改？
沙瓦迪卡:楼主可以发下源码不
沙瓦迪卡:@跑调的安眠曲谢谢楼主
跑调的安眠曲:@沙瓦迪卡 https://github.com/GitterYang/YQSystemPhotoOperation
跑调的安眠曲:@沙瓦迪卡还需要吗？