UICollectionViewDelegateFlowLayout 使用

import UIKit
//UICollectionViewLayout
//itemSize属性
//设定全局的Cell尺寸，如果想要单独定义某个Cell的尺寸，可以使用下面方法：
//    - (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath
//
//minimumLineSpacing属性
//设定全局的行间距，如果想要设定指定区内Cell的最小行距，可以使用下面方法：
//- (CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout minimumLineSpacingForSectionAtIndex:(NSInteger)section
//
//minimumInteritemSpacing属性
//设定全局的Cell间距，如果想要设定指定区内Cell的最小间距，可以使用下面方法：
//- (CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout minimumInteritemSpacingForSectionAtIndex:(NSInteger)section;
//
//scrollDirection属性
//设定滚动方向，有UICollectionViewScrollDirectionVertical和UICollectionViewScrollDirectionHorizontal两个值。
//
//headerReferenceSize属性与footerReferenceSize属性
//设定页眉和页脚的全局尺寸，需要注意的是，根据滚动方向不同，header和footer的width和height中只有一个会起作用。如果要单独设置指定区内的页面和页脚尺寸，可以使用下面方法：
//- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout referenceSizeForHeaderInSection:(NSInteger)section
//- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout referenceSizeForFooterInSection:(NSInteger)section
//
//sectionInset属性
//设定全局的区内边距，如果想要设定指定区的内边距，可以使用下面方法：
//- (UIEdgeInsets)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout insetForSectionAtIndex:(NSInteger)section;
//因为UICollectionViewDelegateFlowLayout实际上是UICollectionViewDelegate的一个子协议，它继承了UICollectionViewDelegate，所以只需要在声明处写上UICollectionViewDelegateFlowLayout就行了。
class ViewController: UIViewController , UICollectionViewDataSource ,UICollectionViewDelegateFlowLayout {
    let cellIdentity = "cellIdentity"
    let cellhead = "cellhead"
    let cellfoot = "cellfoot"
    let sectioncount =
    let datas  =  ["cell1" , "cell2" , "cell3"]
    var collect:UICollectionView!

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
        self.navigationItem.title = "image"
        self.view.backgroundColor = UIColor.whiteColor()

        let layout = UICollectionViewFlowLayout()
        collect = UICollectionView(frame: CGRectMake(, , self.view.frame.size.width-,self.view.frame.size.height-) , collectionViewLayout: layout)
        collect.delegate = self
        collect.dataSource = self
        self.view.addSubview(collect)

        collect.backgroundColor = UIColor.whiteColor()
        collect.layer.borderWidth=

        collect.registerClass(UICollectionViewCell.self, forCellWithReuseIdentifier: cellIdentity)
        collect.registerClass(CollectionReusableView.self, forSupplementaryViewOfKind: UICollectionElementKindSectionHeader, withReuseIdentifier: cellhead)
        collect.registerClass(CollectionReusableView.self, forSupplementaryViewOfKind: UICollectionElementKindSectionFooter, withReuseIdentifier: cellfoot)

    }

    //datasource
    func numberOfSectionsInCollectionView(collectionView: UICollectionView) -> Int {
        return sectioncount
    }
    func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        return datas.count
    }
    func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
        let cell = collectionView.dequeueReusableCellWithReuseIdentifier(cellIdentity, forIndexPath: indexPath)
        cell.layer.borderWidth=

        for v in cell.contentView.subviews{
            v.removeFromSuperview()
        }
        let lab = UILabel(frame: CGRectMake( ,  , cell.frame.size.width- , cell.frame.size.height-))
        lab.numberOfLines =
        lab.text = "\(datas[indexPath.item])（\(indexPath.section)-\(indexPath.item)）"
        cell.contentView.addSubview(lab)
        return cell
    }

    //页眉页脚
    func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, referenceSizeForFooterInSection section: Int) -> CGSize {
        return CGSizeMake(, )
    }
    func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, referenceSizeForHeaderInSection section: Int) -> CGSize {
        return CGSizeMake(, )
    }
    func collectionView(collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, atIndexPath indexPath: NSIndexPath) ->UICollectionReusableView {
        var reusable:CollectionReusableView! = nil

        if kind == UICollectionElementKindSectionHeader {
            reusable = collectionView.dequeueReusableSupplementaryViewOfKind(UICollectionElementKindSectionHeader, withReuseIdentifier: cellhead, forIndexPath: indexPath) as! CollectionReusableView

            reusable.labText(cellhead)
        }else if kind == UICollectionElementKindSectionFooter {
            reusable = collectionView.dequeueReusableSupplementaryViewOfKind(UICollectionElementKindSectionFooter, withReuseIdentifier: cellfoot, forIndexPath: indexPath) as! CollectionReusableView

            reusable.labText(cellfoot)
        }
        reusable.layer.borderWidth=
        return reusable
    }

    //UICollectionViewDelegateFlowLayout
    //设定collectionView(指定区)的边距
    func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, insetForSectionAtIndex section: Int) -> UIEdgeInsets {
        return UIEdgeInsets(top: , left: , bottom: , right: )
    }
    //设定指定区内Cell的最小间距，也可以直接设置UICollectionViewFlowLayout的minimumInteritemSpacing属性
    func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumInteritemSpacingForSectionAtIndex section: Int) -> CGFloat{
        return
    }
    //设定指定区内Cell的最小行距，也可以直接设置UICollectionViewFlowLayout的minimumLineSpacing属性
    func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumLineSpacingForSectionAtIndex section: Int) -> CGFloat {
        return
    }
    //设定指定Cell的尺寸
    func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAtIndexPath indexPath: NSIndexPath) -> CGSize {
        return CGSizeMake(, )
    }

    //当指定indexPath处的item被选择时触发
    func collectionView(collectionView: UICollectionView, didSelectItemAtIndexPath indexPath: NSIndexPath) {
        print("didSelectItemAtIndexPath ++ \(indexPath)")
    }

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