swift中collectionView的简单用法

Posted 2020-07-12 zhangxianhongx

之前写过OC中collectionView的用法，现在再看看swift中collectionView的用法，有兴趣的朋友，可以两者前后比较下区别，swift现在没有稳定下来，语法更新的比较快，但是它核心的一些东西，已经定型了。这些还是靠读者们自己去挖掘吧。

//这里签署数据源和代理，此时不需要引入layout的代理，也可以。
class AmonViewController: UIViewController ,UICollectionViewDataSource,UICollectionViewDelegate{

    var _collectionView:UICollectionView?;
    var _dataArray:NSArray?;
    
    override func viewWillAppear(animated: Bool) {
        super.viewWillAppear(animated);

        self.tabBarController?.tabBar.hidden = false;

//        let x = self._collectionView!.contentOffset.x/kScreenW;
//        UIView.animateWithDuration(0.25) { () -> Void in
//            
//            self._collectionView?.contentOffset = CGPointMake(kScreenW * CGFloat(Int64(x)) + 10 * CGFloat(Int64(x)), 0);
//        };
    }
    override func viewDidLoad() {
        super.viewDidLoad()
        self.title = "排行";
//此属性设置为false可以解决由于scrollview引起的界面bug
        self.automaticallyAdjustsScrollViewInsets = false;
        self.navigationController?.navigationBar.barTintColor = UIColor.whiteColor();
        let headerView = AmonCirHeadView(frame: CGRectMake(0, 64, kScreenW, 150));
        self.view.addSubview(headerView);
        
    
     //创建layout
        let layOut = UICollectionViewFlowLayout();
    //设置滚动方向
//        layOut.scrollDirection = UICollectionViewScrollDirectionHorizontal;
        layOut.scrollDirection = UICollectionViewScrollDirection.Horizontal;
        layOut.itemSize = CGSizeMake(kScreenW, kScreenH-headerView.bounds.size.height-49-64);
        //垂直方向间距
        layOut.minimumInteritemSpacing = 0;
        //水平方向间距
        layOut.minimumLineSpacing = 0;
        //设置四周得边缘距离
        layOut.sectionInset = UIEdgeInsetsMake(0, 0, 0, 0);
        _collectionView = UICollectionView(frame: CGRectMake(0, headerView.bottom, kScreenW, kScreenH-headerView.bounds.size.height-49-64), collectionViewLayout: layOut);
        self.view.addSubview(_collectionView!);
        
        _collectionView?.delegate = self;
        _collectionView?.dataSource = self;
//是否分页
        _collectionView?.pagingEnabled = true;
        _collectionView?.backgroundColor = UIColor.whiteColor();
    _collectionView?.registerClass(UICollectionViewCell().classForCoder, forCellWithReuseIdentifier: "item");
        
        loadData();
    }

    //data Source
    func numberOfSectionsInCollectionView(collectionView: UICollectionView) -> Int {
        return 1;
    }
    func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        if self._dataArray==nil{
            
            return 0;
        }
        return (self._dataArray?.count)!;
    }
    func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
        let cell = collectionView.dequeueReusableCellWithReuseIdentifier("item", forIndexPath: indexPath);
        
        var imgV = cell.contentView.viewWithTag(2016052519) as? UIImageView;
        var lab = cell.contentView.viewWithTag(2016052520) as? UILabel;
        if imgV == nil{
            imgV = UIImageView(frame: cell.bounds);
            cell.contentView.addSubview(imgV!);
            imgV?.tag = 2016052519;
            imgV!.image = UIImage(named: "AION-天气背景.jpg");
            lab = UILabel();
            lab?.frame = CGRectMake(0, 0, kScreenW, 30);
            lab!.tag = 2016052520;

            lab?.textAlignment = NSTextAlignment.Center;
            lab?.textColor = UIColor.whiteColor();
            lab?.backgroundColor = UIColor.blackColor();
            lab?.alpha = 0.3;
            cell.contentView.addSubview(lab!);
            lab?.numberOfLines = 0;
            lab?.font = UIFont.systemFontOfSize(12);
            lab?.text = "最好看的小说，尽在BQPReader";
        }
//数据解析
        let dic1 = self._dataArray![indexPath.item] as! NSDictionary;
        let dic = dic1.objectForKey("content") as! NSDictionary;
        let title = dic.objectForKey("title") as! String;
        let desc = dic.objectForKey("desc") as! String;
        lab?.text = title + "\n" + desc;
        
        return cell;
    }

    
    func scrollViewDidEndDecelerating(scrollView: UIScrollView) {
//        let x = scrollView.contentOffset.x/kScreenW;
//        UIView.animateWithDuration(0.25) { () -> Void in
        
//        self._collectionView?.contentOffset = CGPointMake(kScreenW * CGFloat(Int64(x)) + 10 * CGFloat(Int64(x)), 0);
//        };
        
    }
    //delegate
    func collectionView(collectionView: UICollectionView, didSelectItemAtIndexPath indexPath: NSIndexPath) {
        let viewC = SecAmonViewController();
        let dic1 = self._dataArray![indexPath.item] as! NSDictionary;
        let dic = dic1.objectForKey("content") as! NSDictionary;
        viewC.title = dic.objectForKey("title") as? String;
        self.navigationController?.pushViewController(viewC, animated: true);
    }
    //自定义的数据请求方法
    func loadData(){
        CoreWork.homeOneSecondThirdList { (responsObject) -> Void in

            let firDic = responsObject;
            if firDic.isKindOfClass(NSDictionary) == false{
                return;
            }
            let secondDic = firDic.objectForKey("data") as! NSDictionary;
            self._dataArray = secondDic.objectForKey("md")?.objectForKey("module") as? NSArray;
            
            self._collectionView?.reloadData();
        }
    
    }
    
}