UIcollectionView 间距

Question

我有 10 个单元格，其中第 6 个单元格的宽度必须与其他单元格不同。我尝试在流委托方法中更改它。但是从第 7 个到第 10 个单元格的间距出了点问题。

 func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAtIndexPath indexPath: NSIndexPath) -> CGSize {

    let widthOfCollectionView  = collectionView.bounds.width - 40;

 // For collectionView use "item" instead of "row" 
    if indexPath.item == 6{
        return CGSizeMake(widthOfCollectionView,100)
    }else{
        return CGSizeMake(widthOfCollectionView/3, 100)
    }
}

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

    return 10;
}

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

func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, insetForSectionAtIndex section: Int) -> UIEdgeInsets{

    return UIEdgeInsetsMake(5, 5, 5, 5);
}

Answer 1

我对你的代码做了如下修改：

 import UIKit

    class ViewController: UIViewController,UICollectionViewDataSource, UICollectionViewDelegate  {

        @IBOutlet weak var sampleCollectionView: UICollectionView!

        let reuseIdentifier = "cell"

        let insetValue: CGFloat = 5.0

        override func viewDidLoad() {
            super.viewDidLoad()
            // Do any additional setup after loading the view, typically from a nib.
        }

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

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

        // make a cell for each cell index path
        func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {

            // get a reference to our storyboard cell
            let cell = collectionView.dequeueReusableCellWithReuseIdentifier(reuseIdentifier, forIndexPath: indexPath)
            // Use the outlet in our custom class to get a reference to the UILabel in the cell

            return cell
        }

        func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAtIndexPath indexPath: NSIndexPath) -> CGSize {

            if indexPath.item == 6{
                return CGSizeMake(collectionView.bounds.width - insetValue * 2,100)
            }else{
                return CGSizeMake(floor((collectionView.bounds.width - insetValue * 4)/3), 100)
            }
        }

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

            return insetValue;
        }

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

        func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, insetForSectionAtIndex section: Int) -> UIEdgeInsets{

            return UIEdgeInsetsMake(insetValue, insetValue, insetValue, insetValue);
        }


    }

最终输出：

要下载示例项目，请使用以下链接：

https://github.com/k-sathireddy/SampleCollectionView

Answer 2

对于小项目的宽度，您应该返回(collectionView.bounds.width - 30)/3，左侧插图为 5，右侧插图为 5，间距 = 30 为 2*10。
对于大项目的宽度，您应该返回collectionView.bounds.width - 10，左侧为 5，右侧插入为 5 = 10。

你可以替换这个

func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAtIndexPath indexPath: NSIndexPath) -> CGSize {

    let widthOfCollectionView  = collectionView.bounds.width - 40;
    if indexPath.item == 6{
        return CGSizeMake(widthOfCollectionView,100)
    }else{
        return CGSizeMake(widthOfCollectionView/3, 100)
    }
}

有

func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAtIndexPath indexPath: NSIndexPath) -> CGSize {

    let smallItemWidth = floor((collectionView.bounds.width - 30)/3 * 1000) / 1000
    let largeItemWidth = collectionView.bounds.width - 10

    if indexPath.item == 6{
        return CGSizeMake(largeItemWidth, 100)
    }else{
        return CGSizeMake(smallItemWidth, 100)
    }
}

*使用 floor() 舍入大小数