import UIKit

class CustomCollectionViewCell: UICollectionViewCell {
    @IBOutlet weak var label: UILabel!
    @IBOutlet weak var okBtn: UIButton!

    override func awakeFromNib() {
        super.awakeFromNib()
        // 在这里实现对控件的布局
    }

}

import UIKit

class ViewController: UIViewController,UICollectionViewDataSource,UICollectionViewDelegateFlowLayout {

    // UICollectionViewDelegateFlowLayout已经实现了UICollectionViewDelegate： public protocol UICollectionViewDelegateFlowLayout : UICollectionViewDelegate
    @IBOutlet weak var collectionView: UICollectionView!

    private let cellIdentifier = "collectionCell"

    override func viewDidLoad() {
        super.viewDidLoad()
        self.collectionView.dataSource = self
        self.collectionView.delegate = self
        // 从nib中注册cell，适用于通过xib创建cell的情况；如果是通过代码创建的cell，则使用registerClass方法
        collectionView.registerNib(UINib(nibName: "CustomCollectionViewCell", bundle: nil), forCellWithReuseIdentifier:cellIdentifier)
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    // UICollectionViewDataSource
    func numberOfSectionsInCollectionView(collectionView: UICollectionView) -> Int {
        return 1
    }

    func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        return 10
    }

    func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
        let cell = collectionView.dequeueReusableCellWithReuseIdentifier(cellIdentifier, forIndexPath: indexPath) as! CustomCollectionViewCell
        cell.label.text = "success"
        return cell
    }

    // UICollectionViewDelegateFlowLayout
    func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAtIndexPath indexPath: NSIndexPath) -> CGSize {
        return CGSize(width: 200, height: 200)
    }

    func collectionView(collectionView: UICollectionView,layout collectionViewLayout: UICollectionViewLayout, minimumInteritemSpacingForSectionAtIndex section: Int) -> CGFloat {
            return 5.0
    }

    func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumLineSpacingForSectionAtIndex section: Int) -> CGFloat {
            return 1.0
    }

    func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, insetForSectionAtIndex section: Int) -> UIEdgeInsets {
//        let frame : CGRect = self.view.frame
//        let margin  = (frame.width - 90 * 3) / 6.0
        return UIEdgeInsetsMake(1, 1, 10, 1) // margin between cells
    }
}