有没有办法获取我的iOS应用屏幕截图的列表？

Question

is there a way, in my iOS app, to access to all the screenshots taken from my app ?

If not possible, is there a way to open the image picker controller (UIImagePickerController) with only the screenshot album (from all apps) ?

Thank you.

Answer 1

There's no way to present standard UIImagePickerController with source type other than defined here

https://developer.apple.com/library/ios/documentation/UIKit/Reference/UIImagePickerController_Class/#//apple_ref/c/tdef/UIImagePickerControllerSourceType

However, there is a way to grab screenshots' album and present it in own UI. According to documentation you can do something like this:

let options = PHFetchOptions()
options.predicate = NSPredicate(format: "localizedTitle = Screenshots")
let collections = PHAssetCollection.fetchAssetCollectionsWithType(.SmartAlbum, subtype: .Any, options: options)
let sceenShots = collections.firstObject as? PHAssetCollection

but due to bug (above will crash because of predicate) you can fetch all albums and then filter for screenshots' album (works for iOS8+)

let collections = PHAssetCollection.fetchAssetCollectionsWithType(.SmartAlbum, subtype: .Any, options: nil)
var screenshots: PHAssetCollection?
collections.enumerateObjectsUsingBlock {
    (collection, _, _) -> Void in
    if collection.localizedTitle == "Screenshots" {
        screenshots = collection as? PHAssetCollection
    }
}

Or If you target for iOS9+ you can do like this:

let collections = PHAssetCollection.fetchAssetCollectionsWithType(.SmartAlbum, subtype: .SmartAlbumScreenshots, options: nil)
let screenshots = collections.lastObject as? PHAssetCollection

Please also keep in mind, that it's not possible to grab screenshots from specific app.

Answer 2

I have also considered a different way to access to all the screenshots taken from my app. The idea is to intercept the screenshot with the UIApplicationUserDidTakeScreenshotNotification and then retrieve and save the file URL (or copy the file) :

[[NSNotificationCenter defaultCenter] addObserver:self
                                        selector:@selector(screenshotDetected) name:UIApplicationUserDidTakeScreenshotNotification object:nil];

---

- (void)screenshotDetected {

    PHFetchResult<PHAssetCollection *> *albums = [PHAssetCollection fetchAssetCollectionsWithType:PHAssetCollectionTypeSmartAlbum subtype:PHAssetCollectionSubtypeSmartAlbumScreenshots options:nil];
    [albums enumerateObjectsUsingBlock:^(PHAssetCollection * _Nonnull album, NSUInteger idx, BOOL * _Nonnull stop) {

        PHFetchOptions *options = [[PHFetchOptions alloc] init];
        options.wantsIncrementalChangeDetails = YES;
        options.predicate = [NSPredicate predicateWithFormat:@"mediaType == %d",PHAssetMediaTypeImage];

        PHFetchResult<PHAsset *> *assets = [PHAsset fetchAssetsInAssetCollection:album options:options];
        [assets enumerateObjectsUsingBlock:^(PHAsset * _Nonnull asset, NSUInteger idx, BOOL * _Nonnull stop) {
            // do things
        }];
    }];
}

The problem is the last screenshot, the one that triggered the notification, is not yet available at the time of the code is executed.