声明属性

var collectionView :UICollectionView?
var flowLayout :UICollectionViewFlowLayout?
var arrayM :NSMutableArray?
 var image :UIImage?
 var imageView :UIImageView?

createCollectionView

func createCollectionView() {
        // 将属性初始化
        self.flowLayout = UICollectionViewFlowLayout()
        self.collectionView = UICollectionView(frame: self.view.frame, collectionViewLayout: self.flowLayout!)
        
        self.arrayM = NSMutableArray()
        
        // 准备数据
        for i in 0..<9 {
            self.image = UIImage(named: "\(i).jpg")
            self.arrayM!.addObject(self.image!)
        }
        
        // 设置数据源和代理
        self.collectionView?.dataSource = self
        self.collectionView?.delegate = self
        
        // 流式布局时设置集合视图单元格大小
        self.flowLayout!.itemSize = CGSizeMake(75, 75)
        
        // 注册cell
        self.collectionView!.registerClass(UICollectionViewCell.classForCoder(), forCellWithReuseIdentifier: "collectionReuse")
        
        // 将集合视图添加到视图中
        self.collectionView?.backgroundColor = Theme.BackgroundColor
        self.view.addSubview(self.collectionView!)
    }

UICollectionViewDataSource & UICollectionViewDelegateFlowLayout

extension ViewController : UICollectionViewDataSource,UICollectionViewDelegateFlowLayout {
    
    // MARK:- UICollectionViewDataSource
    // 定义展示的Section的个数
    func numberOfSectionsInCollectionView(collectionView: UICollectionView) -> Int {
        return 1
    }
    
    // 定义展示的UICollectionViewCell的个数
    func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        return arrayM!.count
    }
    
    // 每个UICollectionView展示的内容
    func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
        
        let Reuseidentifier:NSString = "collectionReuse"
        var cell:UICollectionViewCell? = collectionView.dequeueReusableCellWithReuseIdentifier(Reuseidentifier as String, forIndexPath: indexPath) as UICollectionViewCell
        
        if cell == nil {
            print("cell is nil")
            cell = UICollectionViewCell()
        }
        
        self.imageView = UIImageView(frame: CGRectMake(0, 0, 75, 75))
        self.imageView?.image = self.arrayM!.objectAtIndex(indexPath.item) as? UIImage
        
        let label:UILabel? = UILabel(frame: CGRectMake(20,80,75,20))
        label!.text = "{0,\(indexPath.item)}"
        
        cell!.addSubview(imageView!)
        cell!.addSubview(label!)
        
        return cell!
    }
    
    
    // MARK:- UICollectionViewDelegateFlowLayout
    // 设置cell和视图边的间距
    func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, insetForSectionAtIndex section: Int) -> UIEdgeInsets {
        return UIEdgeInsetsMake(10, 20, 10, 20)
    }
    
    // 设置每一个cell最小行间距
    func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumLineSpacingForSectionAtIndex section: Int) -> CGFloat {
        return 30
    }
    
    // 设置每一个cell的列间距
    func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumInteritemSpacingForSectionAtIndex section: Int) -> CGFloat {
        return 10
    }
    
    // 某个Cell被选择的事件处理
    func collectionView(collectionView: UICollectionView, didSelectItemAtIndexPath indexPath: NSIndexPath) {
        
        if indexPath.section == 0 {
            print("选中1区第\(indexPath.row)行")
        } else if indexPath.section == 1 {
            print("选中2区第\(indexPath.row)行")
        } else {
            print("选中3区第\(indexPath.row)行")
        }
        
        
    }
    
}

运行效果