[英]How can I display selected images from the Photo Library or Camera in a CollectionView? Gallery view
[英]How to display images that in photo gallery that were just selected?
目標:用戶從她的相冊中選擇照片>點擊“完成”>顯示照片。
問題: “完成”后,照片不會立即顯示。 如果我再次打開選擇器並點擊“取消”,它們就會顯示出來。
當我使用UIImagePickerController時,這種方法效果很好(照片立即顯示出來),但是后來我切換到ELCImagePickerController進行了多次選擇,因此它不再起作用。
預感
collectionView.reloadData()
后嘗試調用collectionView.reloadData()
)。 這沒有用。 如果有幫助,這是我的ViewController.swift
elcImagePickerController
函數
func elcImagePickerController(picker: ELCImagePickerController!, didFinishPickingMediaWithInfo info: [AnyObject]!) {
println("inside elcImagePickerController")
self.dismissViewControllerAnimated(true, completion: nil)
if (info.count == 0) {
return
}
var pickedImages = NSMutableArray()
for any in info {
let dict = any as! NSMutableDictionary
let image = dict.objectForKey(UIImagePickerControllerOriginalImage) as! UIImage
pickedImages.addObject(image)
}
let priority = DISPATCH_QUEUE_PRIORITY_DEFAULT
dispatch_async(dispatch_get_global_queue(priority, 0), {
PHPhotoLibrary.sharedPhotoLibrary().performChanges(
{
for img in pickedImages{
// Request creating an asset from the image
// create multiple creationRequestForAssetFromImage
let createAssetRequest = PHAssetChangeRequest.creationRequestForAssetFromImage(img as! UIImage) // add to main gallery
// / Request editing the album
let albumChangeRequest = PHAssetCollectionChangeRequest(forAssetCollection: self.assetCollection, assets: self.photosAsset)
// Get a placeholder for the new asset and add it to the album editing request
let assetPlaceholder = createAssetRequest.placeholderForCreatedAsset
albumChangeRequest.addAssets([assetPlaceholder])
}
}, completionHandler: {(success, error) in
NSLog("Adding Image to Library -> %@", (success ? "Success" : "Error"))
picker.dismissViewControllerAnimated(true, completion: nil)
}
)
})
我花了一段時間來復制您的情況和錯誤,但是我設法解決了,找到了解決方案!
你是用呼喚正確的道路上collectionView.reloadData()
在completionHandler
,但它需要更多的工作。
1)
在我的測試場景中,我用了一個PHFetchResult
稱為photosAsset
作為主要來源UICollectionView
(我假設你有一個類似的設置)。
您必須更新此PHFetchResult
以反映最近的更改,在我的情況下,我使用了以下行:
self.photosAsset = PHAsset.fetchAssetsInAssetCollection(self.assetCollection, options: nil)
2)
這是正確的,你必須重新加載與視圖collectionView.reloadData()
但里面的代碼completionHandler
沒有主線程/ UI線程上運行。 因此,您必須按以下方式調用它:
dispatch_async(dispatch_get_main_queue(), {self.collectionView?.reloadData()})
總結:
最后,您的completionHandler
應該看起來類似於以下內容:
completionHandler: {(success, error) in
NSLog("Adding Image to Library -> %@", (success ? "Success" : "Error"))
self.photosAsset = PHAsset.fetchAssetsInAssetCollection(self.assetCollection, options: nil)
dispatch_async(dispatch_get_main_queue(), {self.collectionView?.reloadData()})
picker.dismissViewControllerAnimated(true, completion: nil)
}
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