您可以使用 iOS8 发布的 Photos Framework 来做到这一点。
阅读关于变更观察者 Link
的文档
苹果样品sample
改变观察。使用共享 PHPhotoLibrary 对象为您获取的资产和集合注册更改处理程序。每当另一个应用程序或设备更改资产的内容或元数据或集合中的资产列表时，照片都会告诉您的应用程序。
PH变化
对象在每次更改之前和之后提供有关对象状态的信息，其语义使更新集合视图或类似界面变得容易
如果照片应用有任何更新，您可以使用 **photos 框架拍照
首先你需要注册照片观察者
- (void)applicationWillTerminate:(UIApplication *)application {
[[PHPhotoLibrary sharedPhotoLibrary] unregisterChangeObserver:self];
}
- (void)applicationDidBecomeActive:(UIApplication *)application {
[FBSDKAppEvents activateApp];
[[UIApplication sharedApplication] endBackgroundTask:UIBackgroundTaskInvalid];
[[PHPhotoLibrary sharedPhotoLibrary] unregisterChangeObserver:self];
// dispatch_async(dispatch_get_global_queue( DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^(void){
// //Background Thread
// isBackgroundOrForeground = YES;
// [self getGreenEvent];
// dispatch_async(dispatch_get_main_queue(), ^(void){
// //Run UI Updates
// });
// });
}
- (void)applicationDidEnterBackground:(UIApplication *)application {
NSLog(@"=== DID ENTER BACKGROUND ===");
bgTask = [[UIApplication sharedApplication] beginBackgroundTaskWithExpirationHandler:^{
}];
if (bgTask == UIBackgroundTaskInvalid) {
NSLog(@"This application does not support background mode");
} else {
//if application supports background mode, we'll see this log.
NSLog(@"Application will continue to run in background");
[PHPhotoLibrary requestAuthorization:^(PHAuthorizationStatus status) {
if (status == PHAuthorizationStatusAuthorized) {
[PHPhotoLibrary.sharedPhotoLibrary registerChangeObserver:self];
}
}];
[[PHPhotoLibrary sharedPhotoLibrary] registerChangeObserver:self];
isBackgroundOrForeground = NO;
NSString *oAuthToken = [[NSUserDefaults standardUserDefaults]stringForKey:KEY_ACCESS_TOKEN];
if(oAuthToken.length!=0 || oAuthToken!=nil)
[self getGreenEvent];
}
// Use this method to release shared resources, save user data, invalidate timers, and store enough application state information to restore your application to its current state in case it is terminated later.
// If your application supports background execution, this method is called instead of applicationWillTerminate: when the user quits.
}
编译指示标记 - PHPhotoLibraryChangeObserver
- (void)photoLibraryDidChange:(PHChange *)changeInstance {
NSLog(@"content being changed");
/*
Change notifications may be made on a background queue. Re-dispatch to the
main queue before acting on the change as we'll be updating the UI.
*/
__block BOOL reloadRequired = NO;
__block NSIndexSet *removedIndex;
__block NSIndexSet *insertedIndexes;
dispatch_async(dispatch_get_main_queue(), ^{
// Loop through the section fetch results, replacing any fetch results that have been updated.
NSMutableArray *updatedSectionFetchResults = [self.sectionFetchResults mutableCopy];
// __block BOOL reloadRequired = NO;
[self.sectionFetchResults enumerateObjectsUsingBlock:^(PHFetchResult *collectionsFetchResult, NSUInteger index, BOOL *stop) {
PHFetchResultChangeDetails *changeDetails = [changeInstance changeDetailsForFetchResult:collectionsFetchResult];
removedIndex = changeDetails.removedIndexes;
insertedIndexes = changeDetails.insertedIndexes;
if (changeDetails != nil) {
[updatedSectionFetchResults replaceObjectAtIndex:index withObject:[changeDetails fetchResultAfterChanges]];
reloadRequired = YES;
self.sectionFetchResults = updatedSectionFetchResults;
if(insertedIndexes != nil){
[self backgroundUpload];
}else{
}
}
}];
if (reloadRequired) {
self.sectionFetchResults = updatedSectionFetchResults;
}
});
}
-(void)getAllPhotosFromCamera{
PHFetchOptions *allPhotosOptions = [[PHFetchOptions alloc] init];
allPhotosOptions.sortDescriptors = @[[NSSortDescriptor sortDescriptorWithKey:@"creationDate" ascending:YES]];
PHFetchResult *allPhotos = [PHAsset fetchAssetsWithOptions:allPhotosOptions];
PHFetchResult *smartAlbums = [PHAssetCollection fetchAssetCollectionsWithType:PHAssetCollectionTypeSmartAlbum subtype:PHAssetCollectionSubtypeAlbumRegular options:nil];
PHFetchResult *topLevelUserCollections = [PHCollectionList fetchTopLevelUserCollectionsWithOptions:nil];
// Store the PHFetchResult objects and localized titles for each section.
self.sectionFetchResults = @[allPhotos, smartAlbums, topLevelUserCollections];
}
-(NSMutableArray *)getNumberOfPhotoFromCameraRoll:(NSArray *)array{
PHFetchResult *fetchResult = array[1];
int index = 0;
unsigned long pictures = 0;
for(int i = 0; i < fetchResult.count; i++){
unsigned long temp = 0;
temp = [PHAsset fetchAssetsInAssetCollection:fetchResult[i] options:nil].count;
if(temp > pictures ){
pictures = temp;
index = i;
}
}
PHCollection *collection = fetchResult[index];
if (![collection isKindOfClass:[PHAssetCollection class]]) {
// return;
}
// Configure the AAPLAssetGridViewController with the asset collection.
PHAssetCollection *assetCollection = (PHAssetCollection *)collection;
PHFetchResult *assetsFetchResult = [PHAsset fetchAssetsInAssetCollection:assetCollection options:nil];
self. assetsFetchResults = assetsFetchResult;
self. assetCollection = assetCollection;
self.numberOfPhotoArray = [NSMutableArray array];
for (int i = 0; i<[assetsFetchResult count]; i++) {
PHAsset *asset = assetsFetchResult[i];
[self.numberOfPhotoArray addObject:asset];
}
NSLog(@"%lu",(unsigned long)[self.numberOfPhotoArray count]);
return self.numberOfPhotoArray;
}
其中 bgTask 是
的全局对象
UIBackgroundTaskIdentifier bgTask;
@property (nonatomic, strong) NSArray *sectionFetchResults;
@property (nonatomic, strong) PHFetchResult *assetsFetchResults;
@property (nonatomic, strong) PHAssetCollection *assetCollection;
@property (nonatomic, strong) NSMutableArray *numberOfPhotoArray;