Swift UICollectionView 使用

import Foundation
import UIKit

class MainPageViewController: UIViewController,UICollectionViewDelegate,UICollectionViewDataSource,UICollectionViewDelegateFlowLayout {

var collectionView:UICollectionView?;

let CELL_ID = "cell_id";
let HEAD_ID = "head_id";

override func viewDidLoad() {
super.viewDidLoad();

self.view.backgroundColor = UIColor.blueColor();
self.title = "首页";
createCollectionView();
}

func createCollectionView() {

let flowLayout = UICollectionViewFlowLayout();
collectionView = UICollectionView(frame: CGRectMake(0, 0, SCREEN_WIDTH, SCREEN_HEIGHT),collectionViewLayout:flowLayout);
collectionView!.backgroundColor = UIColor.orangeColor();
collectionView!.delegate = self;
collectionView!.dataSource = self;

collectionView!.registerClass(MainPageSectionZeroCell.self, forCellWithReuseIdentifier: CELL_ID);
collectionView!.registerClass(MainPageSectionZeroHeadView.self, forSupplementaryViewOfKind: UICollectionElementKindSectionHeader, withReuseIdentifier: HEAD_ID);

self.view.addSubview(collectionView!);
}

//MARK: - UICollectionView 代理

//分区数
func numberOfSectionsInCollectionView(collectionView: UICollectionView) -> Int {
return 3;
}

//每个分区含有的 item 个数
func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return 20;
}

//返回 cell
func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {

let cell = collectionView.dequeueReusableCellWithReuseIdentifier(CELL_ID, forIndexPath: indexPath) as! MainPageSectionZeroCell;

return cell;
}

//每个分区的内边距
func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, insetForSectionAtIndex section: Int) -> UIEdgeInsets {
return UIEdgeInsetsMake(10, 10, 10, 10);
}

//最小 item 间距
func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumInteritemSpacingForSectionAtIndex section: Int) -> CGFloat {
return 10;
}

//最小行间距
func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumLineSpacingForSectionAtIndex section: Int) -> CGFloat {
return 10;
}

//item 的尺寸
func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAtIndexPath indexPath: NSIndexPath) -> CGSize {
return CGSizeMake(SCREEN_WIDTH / 4.0 - 50 / 4.0, SCREEN_WIDTH / 4.0 - 50 / 4.0);
}

//每个分区区头尺寸
func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, referenceSizeForHeaderInSection section: Int) -> CGSize {
return CGSizeMake(SCREEN_WIDTH, 40);
}

//返回区头、区尾实例
func collectionView(collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, atIndexPath indexPath: NSIndexPath) -> UICollectionReusableView {

var headview = MainPageSectionZeroHeadView();

if kind == UICollectionElementKindSectionHeader {

headview = collectionView.dequeueReusableSupplementaryViewOfKind(kind, withReuseIdentifier: HEAD_ID, forIndexPath: indexPath) as! MainPageSectionZeroHeadView;

}

return headview;

}

//item 对应的点击事件
func collectionView(collectionView: UICollectionView, didSelectItemAtIndexPath indexPath: NSIndexPath) {
print("index is \(indexPath.row)");
}

}

import Foundation
import UIKit

class MainPageSectionZeroCell: UICollectionViewCell {

override init(frame: CGRect) {
super.init(frame: frame);

let image = UIImage(named: "collts");
let imageV = UIImageView(frame: CGRectMake(0, 0, frame.size.width, frame.size.height));
imageV.image = image;

self.addSubview(imageV);
}

required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}

}

import Foundation
import UIKit

class MainPageSectionZeroHeadView: UICollectionReusableView {

override init(frame: CGRect) {
super.init(frame: frame);

self.backgroundColor = UIColor.whiteColor();
let label = UILabel(frame: CGRectMake(0,0,self.frame.width,self.frame.height));
label.text = "标题";
self.addSubview(label);
}

required init?(coder aDecoder: NSCoder) {
fatalError("init(coder) has not been implemented")
}
}