相册操作（比较卡就是记一下代码不实用）

#pragma mark 相册操作

- (void)getOriginalImages{      

//获取所有自定义相簿   

PHFetchResult*assetCollections = [PHAssetCollection fetchAssetCollectionsWithType:PHAssetCollectionTypeSmartAlbum subtype:PHAssetCollectionSubtypeAlbumRegular options:nil];  

//便利所有相册簿   

for (PHAssetCollection *assetCollection in assetCollections) {       

[self enumerateAssetsInAssetCollection:assetCollection original:YES];      

NSLog(@"相册名%@",assetCollection.localizedTitle);    }  

//    PHAssetCollection *cameraRoll = [PHAssetCollection fetchAssetCollectionsWithType:PHAssetCollectionTypeSmartAlbum subtype:PHAssetCollectionSubtypeSmartAlbumUserLibrary options:nil].lastObject;

//    [self enumerateAssetsInAssetCollection:cameraRoll original:YES];

}

//获取所有相册中的缩略图 //没用

- (void)getThumbnailImages{       

PHFetchResult*assetCollections = [PHAssetCollection fetchAssetCollectionsWithType:PHAssetCollectionTypeSmartAlbum subtype:PHAssetCollectionSubtypeAlbumRegular options:nil];       

for (PHAssetCollection *assetCollection in assetCollections) {       

[self enumerateAssetsInAssetCollection:assetCollection original:NO]; 

 }      

PHAssetCollection *cameraRoll = [PHAssetCollection fetchAssetCollectionsWithType:PHAssetCollectionTypeAlbum subtype:PHAssetCollectionSubtypeSmartAlbumUserLibrary options:nil].lastObject;  

[self enumerateAssetsInAssetCollection:cameraRoll original:NO];}

/* 遍历相册中的原图 @param assetCollection 相册 @param original 是否要原图  */- (void)enumerateAssetsInAssetCollection:(PHAssetCollection *)assetCollection original:(BOOL)original{        PHImageRequestOptions *options = [[PHImageRequestOptions alloc] init];   

//同步获得智慧返回一张    options.synchronous = YES;      

//获得某个相册中所有的phasset对象  

PHFetchResult*assets = [PHAsset fetchAssetsInAssetCollection:assetCollection options:nil];

//    NSLog(@"图片数量:%lu",(unsigned long)assets.count);

if(assets.count){

//

ZCCPhoneAlbumModel *albumModel = [[ZCCPhoneAlbumModel alloc] init];

//        NSLog(@"相册名%@",assetCollection.localizedTitle);

//相册名给对象

albumModel.photoAlbumName = assetCollection.localizedTitle;

NSMutableArray *picsArray = [NSMutableArray array];

for (PHAsset *asset in assets) {

//        CGSize size = original ? CGSizeMake(asset.pixelWidth, asset.pixelHeight) : CGSizeZero;

//宽大于高 就把高变成 asset.pixelHeight * COLLECTIONWIDTH/asset.pixelHeight

CGFloat width = 0;

CGFloat height = 0;

//宽大于高 压缩高

if(asset.pixelWidth > asset.pixelHeight){

width = asset.pixelWidth * COLLECTIONWIDTH/asset.pixelHeight;

height = COLLECTIONWIDTH;

}else{//宽小于高 压缩宽

width = COLLECTIONWIDTH;

height = asset.pixelHeight * COLLECTIONWIDTH/asset.pixelWidth;

}

CGSize size = CGSizeMake(width, height);

//从asset中获得图片

[[PHImageManager defaultManager] requestImageForAsset:asset targetSize:size contentMode:PHImageContentModeDefault options:options resultHandler:^(UIImage * _Nullable result, NSDictionary * _Nullable info) {

//                NSLog(@"%@",result);

[picsArray addObject:result];

}];

}

albumModel.photos = picsArray;

//把这个相册对象添加到相册数组中

[self.photoAlbums addObject:albumModel];

}

}

其实这里可以通过 打开collectionView获取contentoffsize来判断当前滑动位置 然后 加载 总图片的对应阶段图片 边滑动边加载 这样就不会造成刚点开的卡顿了  有空实现一下。