问题

I have 4 different arrays:

var arrayFirst = ["1"]
var arraySecond = ["2"]
var arrayThird = ["3"]
var arrayFourth = ["4"]

Created a Single Array for collection view.

var collectionArrayStr = [arrayFirst,arraySecond,arrayThird,arrayFourth]

func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
    return collectionArrayStr.count
}

func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
    let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "ViewCell", for: indexPath) as! ViewCell

    print(collectionArrayStr[indexPath.row])
    //output:- (["1"])

    if let indexPathSlctedImage = collectionArrayStr[indexPath.row] as? [String] {
        cell.txtHeading.text = indexPathSlctedImage[indexPath.row] // No exact matches in call to subscript 
    }
    return cell
}

I followed the above approach to combine multiple arrays into a single array, but I got the error when I accessed the index value as given below:

No exact matches in call to subscript

Question: How to get an index value in a single array?

Can someone please explain to me how to do this? I've tried with the above code but haven't had any results yet. Please correct me if I'm doing it wrong.

Any help would be greatly appreciated.

var arrayFirst = ["1"]
var arraySecond = ["2"]
var arrayThird = ["3"]
var arrayFourth = ["4"]

 var collectionArrayStr = [arrayFirst,arraySecond,arrayThird,arrayFourth]

 func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
    return collectionArrayStr.count
}

func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
    let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "ViewCell", for: indexPath) as! ViewCell

    print(collectionArrayStr[indexPath.row])
    //output:- (["1"])

    if let indexPathSlctedImage = collectionArrayStr[indexPath.row] as? [String] {
        cell.txtHeading.text = indexPathSlctedImage[indexPath.row] // No exact matches in call to subscript 
    }
    return cell
}

答案1

得分: 1

You are creating an array of arrays using the following code:

var collectionArrayStr = [arrayFirst, arraySecond, arrayThird, arrayFourth]

What you should do is as follows:

var collectionArrayStr: [String] = []
collectionArrayStr.append(contentsOf: arrayFirst)
collectionArrayStr.append(contentsOf: arraySecond)
collectionArrayStr.append(contentsOf: arrayThird)
collectionArrayStr.append(contentsOf: arrayFourth)

print("collectionArrayStr==\(collectionArrayStr)")

The output will be:

collectionArrayStr==["1", "2", "3", "4"]

Now, you can use it in a cell as follows:

cell.txtHeading.text = collectionArrayStr[indexPath.row]

var collectionArrayStr = [arrayFirst,arraySecond,arrayThird,arrayFourth]

var collectionArrayStr : [String] = []
collectionArrayStr.append(contentsOf: arrayFirst)
collectionArrayStr.append(contentsOf: arraySecond)
collectionArrayStr.append(contentsOf: arrayThird)
collectionArrayStr.append(contentsOf: arrayFourth)

print("collectionArrayStr==\(collectionArrayStr)")

collectionArrayStr==["1", "2", "3", "4"]

cell.txtHeading.text = collectionArrayStr[indexPath.row]

答案2

得分: 0

好像你调用了 indexPath.row 两次？

所以你告诉 collectionView 有多少个 sections 和每个 section 中有多少行。这意味着 indexPath.section 和 indexPath.row。

    if let indexPathSlctedImage = collectionArrayStr[indexPath.section] as? [String] {
        cell.txtHeading.text = indexPathSlctedImage[indexPath.row] 
    }

<details>
<summary>英文:</summary>

It looks like you are calling indexPath.row twice?

So you tell the collectionView the amount of sections and amount of rows in section. That means indexPath.section and indexPath.row.

if let indexPathSlctedImage = collectionArrayStr[indexPath.section] as? [String] {
    cell.txtHeading.text = indexPathSlctedImage[indexPath.row] 
}