从IOS中的相册获取今天的照片

Question

有没有什么办法从ios中的相册中获取当天的照片？ 我知道如何获取相册，但所有照片都显示为时间线。 我只想得到今天的照片或最近两天的照片，我怎么能意识到这一点？ 谢谢。

Answer 1

您可以使用此片段获取适用于iOS 8的今日照片。我最初过滤了最近添加的相册中的资产，该相册可存储过去30天或1000张照片中的照片。用户有机会在两天内拍摄超过1000张照片，因此我更改了代码以获取库中的所有照片。

PHFetchOptions *options = [[PHFetchOptions alloc] init]; 
options.sortDescriptors = @[[NSSortDescriptor sortDescriptorWithKey:@"creationDate" ascending:NO]]; 
options.predicate = [NSPredicate predicateWithFormat:@"mediaType = %d",PHAssetMediaTypeImage]; 

PHFetchResult *assetsFetchResult = [PHAsset fetchAssetsWithOptions:options]; 

//get day component of today 
NSCalendar* calendar = [NSCalendar currentCalendar]; 
NSDateComponents *dayComponent = [calendar components:NSCalendarUnitDay fromDate:[NSDate date]]; 
NSInteger currentDay = dayComponent.day; 

//get day component of yesterday 
dayComponent.day = - 1; 
NSDate *yesterdayDate = [calendar dateByAddingComponents:dayComponent toDate:[NSDate date] options:0]; 
NSInteger yesterDay = [[calendar components:NSCalendarUnitDay fromDate:yesterdayDate] day]; 

//filter assets of today and yesterday add them to an array. 
NSMutableArray *assetsArray = [NSMutableArray array]; 
for (PHAsset *asset in assetsFetchResult) { 
    NSInteger assetDay = [[calendar components:NSCalendarUnitDay fromDate:asset.creationDate] day]; 

    if (assetDay == currentDay || assetDay == yesterDay) { 
     [assetsArray addObject:asset]; 
    } 
    else { 
     //assets is in descending order, so we can break here. 
     break; 
    } 
} 

此前的iOS 8，使用ALAssetsLibrary，假设你有一个照片组，枚举组以相反的顺序，并做类似的事情，如上。

[self.photoGroup enumerateAssetsWithOptions:NSEnumerationReverse usingBlock:^(ALAsset *asset, NSUInteger index, BOOL *stop) { 
     NSDate *date = [asset valueForProperty:ALAssetPropertyDate]; 
    }]; 

Answer 2

你可以使用一个谓词的一天

PHFetchOptions *allPhotosOptions = [PHFetchOptions new]; 
allPhotosOptions.sortDescriptors = @[[NSSortDescriptor sortDescriptorWithKey:@"creationDate" ascending:YES]]; 

NSPredicate *predicateMediaType = [NSPredicate predicateWithFormat:@"mediaType = %d",PHAssetMediaTypeImage]; 
NSDate *date = [[NSDate date] beginningOfDay]; 
NSPredicate *predicateDate = [NSPredicate predicateWithFormat:@"creationDate >= %@", date]; 

NSCompoundPredicate *compoundPredicate = [NSCompoundPredicate andPredicateWithSubpredicates:@[predicateDate, predicateMediaType]]; 


allPhotosOptions.predicate = compoundPredicate; 

PHFetchResult *allPhotosResult = [PHAsset fetchAssetsWithMediaType:PHAssetMediaTypeImage options:allPhotosOptions]; 

凡

@implementation NSDate (Utils) 

- (NSDate *)beginningOfDay { 
NSCalendar *calendar = [NSCalendar currentCalendar]; 

    NSDateComponents *components = [calendar components:CYCalendarUnitYear | CYCalendarUnitMonth | CYCalendarUnitDay fromDate:self]; 

    return [calendar dateFromComponents:components]; 
} 

Answer 3

斯威夫特3版本日期范围：

let fromDate = // the date after which you want to retrieve the photos 
let toDate // the date until which you want to retrieve the photos 

let options = PHFetchOptions() 
options.predicate = NSPredicate(format: "creationDate > %@ && creationDate < %@", fromDate as CVarArg, toDate as CVarArg) 

//Just a way to set order 
let sortDescriptor = NSSortDescriptor(key: "creationDate", ascending: false) 
options.sortDescriptors = [sortDescriptor] 

return PHAsset.fetchAssets(with: .image, options: options)