swift 3中如何使用UIImage数组为零？

Question

I have one array of png images.

iconeImage = [UIImage(named:"ion-home")!,UIImage(named:"ms-medkit")!,UIImage(named:"ion-edit")!,UIImage(named:"ion-clipboard")!,UIImage(named:"ion-clipboard")!,UIImage(named:"ion-waterdrop")!,UIImage(named:"ion-calendar")!]

and I have one function for table-view which set the image with this array elements

here is the code

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCell(withIdentifier: "MenuTableViewCell") as! MenuTableViewCell
        cell.imgIcon.image = iconeImage[indexPath.row]
        return cell
    }

But it gives me error that iconeImage has nil values. so can you suggest me solutions. I am beginner in swift 3

Here is the screenshot ![two muppets][1]

Answer 1

Instead of holding all images in memory I'd suggest you to store image names:

let iconImages = ["ion-home", "ms-medkit", "ion-edit", "ion-clipboard", "ion-waterdrop", "ion-calendar"]

And preload each image directly when you need it. It will not affect on performance as it is small icons. Also code will look cleaner.

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCell(withIdentifier: "MenuTableViewCell") as! MenuTableViewCell
    cell.imgIcon.image = UIImage(named: iconImages[indexPath.row])
    return cell
}

Double check if all the assets are added to your project. If they are there, image should be displayed.

Try to avoid of using implicitly unwrapped optional (!) in your code. Nil value will crash the app. In your example, imageView.image is an optional, so you can set UIImage(named: "imageName") to it.

Also, you can try to clean build folder, clean project and reinstall the app. Sometimes copying resources failed in Xcode.

Answer 2

Please try the below format

  let img = iconeImage[indexPath.row]
    if let imgData = img {
        cell.imgView.image = UIImage(data:imgData)
    }

Answer 3

You can store your image names instead:

let iconImageNames = ["ion-home","ms-medkit", ... , "ion-calendar")]

Later access them in your method:

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCell(withIdentifier: "MenuTableViewCell") as! MenuTableViewCell
    let name = iconeImage[indexPath.row] ?? yourDefaultImageName
    cell.imgIcon.image = UIImage(named: name)
    return cell
}

As an example

Answer 4

I don't know exactly what is the issue.

But when i have searching over stackoverflow. somewhere i have read that something problem with Assets.xcassets

then i got the error exact of this

And then solve the error with the help of that answer.

and hopefully i resolved the error.

meanwhile the problem is with assets folder.