 //        let b = CGFloat(arc4random_uniform(255))/255.0
 //        view.backgroundColor = UIColor(red: r, green: g, blue: b, alpha: 1)
         
-        self.collectionView!.register(JWPhotoBrowserCell.self, forCellWithReuseIdentifier: reuseIdentifier)
+        self.collectionView!.register(JWPhotoBrowserCell.self, forCellWithReuseIdentifier: PBReuseIdentifier)
         
         self.transitioningDelegate = self
         

    override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        
        //1.获取cell
        let cell:JWPhotoBrowserCell = collectionView.dequeueReusableCell(withReuseIdentifier: reuseIdentifier, for: indexPath) as! JWPhotoBrowserCell
        
        //2.设置cell
        cell.photoBrowserItem =  photoSource[indexPath.item]


import UIKit
 
let PBReuseIdentifier:String = "reuseIdentifier"

class JWPhotoBrowserViewController: UICollectionViewController,UIViewControllerTransitioningDelegate{

