2014-12-02 53 views
1

我正在使用照片部分和集合視圖的應用程序。單元格中的圖像模糊。在桌面視圖中以全屏和縮略圖形式顯示在不同的屏幕上時,它們非常銳利。我有一個名爲Photo的NSManagedObject子類,它導入照片,引用PHAssets,幷包含名爲getAsset()和getImage(size)的方法。使用照片套件和Swift在UICollectionViewCell中模糊圖像

這裏是我的UICollectionViewCell子類代碼:

class PhotoCollectionViewCell: UICollectionViewCell { 

@IBOutlet weak var imageForCell: UIImageView! 
@IBOutlet weak var labelForCell: UILabel! 

func setImage (photo: Photo?, size: CGSize) -> Bool { 

    if photo != nil { 
     if let image = photo?.getImage(size) { 
      var label = photo?.getLabel() 

      imageForCell.contentMode = UIViewContentMode.ScaleAspectFit 
      imageForCell.image = image 
      labelForCell.text = label 
      return true 
     } 
    } 
    return false 
} 

從cellForItemAtIndex在我UICollectionView子類:

if let photo: Photo = listOfPhotos[indexPath.item] as? Photo { 

     var size: CGSize = CGSizeMake(500, 350) 

     if !cell.setImage(photo, size: size) { 
      // Handles a missing photo. 
     } 
    } 

2基於其創建日期從照片NSManagedObject子類中找到照片的方法:

func getAsset() -> PHAsset? { 

    let fetchOptions = PHFetchOptions() 
    fetchOptions.predicate = NSPredicate(format: "creationDate = %@", photoDate) 
    let assets = PHAsset.fetchAssetsInAssetCollection(assetCollection, options: fetchOptions) 
    var asset: PHAsset? 
    if assets.count == 1 { 
     asset = assets.lastObject as? PHAsset 
    } 
    else { 
     // Handles invalid result 
    } 
    return asset 
} 

func getImage(size: CGSize) -> UIImage? { 

    var image: UIImage? 

    if let asset = getAsset() { 
     PHImageManager.defaultManager().requestImageForAsset(asset, targetSize: size, contentMode: PHImageContentMode.AspectFit , options: nil) { (result, info) -> Void in 

      image = result 
      println("P gI: Image gotten. Image Size: \(image?.size), Size: \(size), Date: \(asset.creationDate)") 
     } 
    } 
    else { 
    } 
    return image 
} 

getI中的println()語句法師告訴我,這是獲取每個圖像兩次不同大小,都不是指定的大小。首先獲取每個單元的較小尺寸,然後每個單元的尺寸較大。我懷疑這個較小的圖像會被炸燬以填充我的單元格(我認爲這會讓它變得模糊),並且它不會以較大的尺寸加載(我認爲這很明顯)。輸出記錄:

P gI: Image gotten. Image Size: Optional((64.0,48.0)), Size: (500.0,350.0), Date: 2014-12-04 18:56:20 +0000 
P gI: Image gotten. Image Size: Optional((64.0,48.0)), Size: (500.0,350.0), Date: 2014-12-04 18:56:36 +0000 
P gI: Image gotten. Image Size: Optional((2048.0,1530.0)), Size: (500.0,350.0), Date: 2014-12-04 18:56:20 +0000 
P gI: Image gotten. Image Size: Optional((2048.0,1530.0)), Size: (500.0,350.0), Date: 2014-12-04 18:56:36 +0000 

在我的故事板,我的ImageView和細胞兩者都爲250×175。我的ImageView設置爲看點飛度在檢查器中設置。

回答

1

PhotosFramework首先爲速度獲取較小的大小,然後獲取較大的圖像大小。
你可以告訴它通過設置請求選項,只獲取較大的圖像:

let requestOptions = PHImageRequestOptions() 
requestOptions.deliveryMode = .HighQualityFormat 
PHImageManager.defaultManager().requestImageForAsset(asset, targetSize: size, contentMode: PHImageContentMode.AspectFit , options: requestOptions) { (result, info) in 
    // ... 
} 

看到PHImageRequestOptionsDeliveryMode了更多的選擇。