コレクションビューのPNG画像の透明な背景

Question

選択可能な絵文字を表示するコレクションビューがあります。現在のところ、絵文字は私には表示されていますが、これは問題ありませんが、画像ファイル自体には目立たない灰色の背景が目立つようです。

これらの絵文字画像の背景を灰色ではなく透明にすることはできますか？ここで

私のコードです：

import UIKit 

class EmojiPopup: UIView,UICollectionViewDataSource,UICollectionViewDelegate 
{ 
    var collocationView : UICollectionView! 
    var arrImagesList:NSMutableArray! 
    override init(frame: CGRect) 
    { 
     super.init(frame: frame) 
     arrImagesList = NSMutableArray() 
     self.backgroundColor = UIColor.purpleColor().colorWithAlphaComponent(0.1) 
     let layout = UICollectionViewFlowLayout() 
     //header gap 
     layout.headerReferenceSize = CGSizeMake(30,30) 
     //collection view item size 
     layout.itemSize = CGSizeMake(75, 75) 
     layout.minimumInteritemSpacing = 20 
     layout.minimumLineSpacing = 10 
     collocationView = UICollectionView(frame: CGRectMake(50,50,UIScreen.mainScreen().bounds.screenWidth - 100,UIScreen.mainScreen().bounds.screenHeight - 100), collectionViewLayout: layout) 
     self.addSubview(collocationView) 

     collocationView.backgroundColor = UIColor.purpleColor().colorWithAlphaComponent(0.001) 
     collocationView.dataSource = self 
     collocationView.delegate = self 
     collocationView.registerClass(UICollectionViewCell.self, forCellWithReuseIdentifier: "cellIdentifier") 

     let fm = NSFileManager.defaultManager() 
     let path = NSBundle.mainBundle().resourcePath! 
     let items = try! fm.contentsOfDirectoryAtPath(path) 

     for item in items 
     { 
      if item.hasSuffix("png") && item.containsString("@") == false && item.containsString("AppIcon") == false && item.containsString("tick_blue") == false && item.containsString("video_camera") == false 
      { 
       arrImagesList.addObject(item) 
      } 
     } 
    } 
    var completeHandler:((String)->())? 
    func showDetails(viewParent:UIView,doneButtonClick:((String)->())?) 
    { 
     completeHandler = doneButtonClick 
     viewParent.addSubview(self) 
    } 
    func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int 
    { 
     return arrImagesList.count 
    } 

    func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell 
    { 
     let identifier="ImageCell\(indexPath.section)\(indexPath.row)" 
     collectionView.registerClass(ImageViewCell.self, forCellWithReuseIdentifier:identifier) 
     let cell = collectionView.dequeueReusableCellWithReuseIdentifier(identifier, forIndexPath: indexPath) as! ImageViewCell 
     cell.backgroundColor = UIColor(white:1, alpha:0) 
     cell.imgView.image = UIImage(named:arrImagesList[indexPath.row] as! String) 
     cell.imgView.contentMode = .ScaleAspectFit 
     return cell 
    } 
// func collectionView(collectionView: UICollectionView, 
//  layout collectionViewLayout: UICollectionViewLayout, 
//  sizeForItemAtIndexPath indexPath: NSIndexPath) -> CGSize 
// { 
//  let width=UIScreen.mainScreen().bounds.size.width-50 
//  return CGSize(width:width/3, height:width/3) 
// } 

    func collectionView(collectionView: UICollectionView, didSelectItemAtIndexPath indexPath: NSIndexPath) 
    { 
     //let cell=collectionView.cellForItemAtIndexPath(indexPath) as! ImageViewCell 

     UIView.animateWithDuration(0.3, animations:{ 
      self.collocationView.alpha=0 
      }, completion: { finished in 

       if self.completeHandler != nil 
       { 
        self.completeHandler!(self.arrImagesList[indexPath.row] as! String) 
       } 
       self.removeFromSuperview() 
     }) 

    } 
    func showDetails(viewParent:UIView,dictData : [String:String],index:Int,doneButtonClick:(()->())?,cancelBUttonClick:(()->())?) 
    { 
    } 
    required init?(coder aDecoder: NSCoder) { 
     fatalError("init(coder:) has not been implemented") 
    } 
} 

Answer 1

cellForItemAtIndexPath方法で

let cell = collectionView.dequeueReusableCellWithReuseIdentifier(identifier, forIndexPath: indexPath) as! ImageViewCell 
cell.backgroundColor = UIColor(white:1, alpha:0) 
cell.imgView.image = UIImage(named:arrImagesList[indexPath.row] as! String) 
cell.imgView.backgroundColor = UIColor.clearColor() 
cell.imgView.opaque = false 
cell.imgView.contentMode = .ScaleAspectFit 

return cell