Question

我希望我的集合视图只返回特定的数组。我希望它只能从“奥迪”返回到“雪佛兰”或[2 ... 9]。汽车制造和新车制造阵列，都有8的值。他们都应该是相同的，但它给我错误fatal error: Index out of bounds。我做错了什么？？

 var car make = ["Honda","Toyota","AUDI","Bentley","BMW","Mercedes","Buick","Cadillac","KIA","Chevrolet","Corvette","Dodge","FIAT","Ford","GMC","Hyundai","Infiniti","Jaguar","JEEP","LandRover","LEXUS","Mazda","Nissan","RAM","Porsche","Scion","Volkswagen"]

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

            return carmake[2...9].count
    }

    func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
        let cell = viewcontrol.dequeueReusableCellWithReuseIdentifier("cell", forIndexPath: indexPath) as! jobtypeCollectionViewCell

            let newcarmake = carmake[2...9]
            cell.title.text = newcarmake[indexPath.row]
        return cell
    }

Answer 1

carmake[2...9]不是数组，而是ArraySlice和数组切片使用与创建它们的数组相同的索引。因此carmake[2...9]的有效索引为2...9，而不是0...7 正如你所预料的那样。

一种解决方案是创建一个真正的数组：

let newcarmake = Array(carmake[2...9])
cell.title.text = newcarmake[indexPath.row]

或者，用简单的方法引用原始数组偏移计算，例如

cell.title.text = carmake[indexPath.row + 2]

Answer 2

问题在于您的NSIndexPath。你的代码差不多好。它需要一点改变。

func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
    let cell = viewcontrol.dequeueReusableCellWithReuseIdentifier("cell", forIndexPath: indexPath) as! jobtypeCollectionViewCell

    cell.title.text = carmake[indexpath.row + 2]
    return cell
}

newCarMake是一个文本，而不是数组。试试那段代码。

从数组中获取特定值以在NSIndexpath.row中返回

2 个答案: