Question

尝试以编程方式设置按钮的图像时收到“nil”错误。我究竟做错了什么？这些都不是可选项。

@IBOutlet weak var scrollView: UIScrollView!

var imageButton: UIButton!
var index: Int = 0

var images: [UIImage] = [UIImage(named: "image1.png")!, UIImage(named: "image2.png")!, UIImage(named: "image3.png")!, UIImage(named: "image4.png")!, UIImage(named: "image5.png")!, UIImage(named: "image6.png")!, UIImage(named: "image7.png")!, UIImage(named: "image8.png")!, UIImage(named: "image9.png")!, UIImage(named: "image10.png")!, UIImage(named: "image11.png")!, UIImage(named: "image12.png")!, UIImage(named: "image13.png")!, UIImage(named: "image14.png")!, UIImage(named: "image15.png")!, UIImage(named: "image16.png")!, UIImage(named: "image17.png")!, UIImage(named: "image18.png")!, UIImage(named: "image19.png")!, UIImage(named: "image20.png")!, UIImage(named: "image21.png")!, UIImage(named: "image22.png")!, UIImage(named: "image23.png")!, UIImage(named: "image24.png")!, UIImage(named: "image25.png")!, UIImage(named: "image26.png")!, UIImage(named: "image27.png")!, UIImage(named: "image28.png")!, UIImage(named: "image29.png")!, UIImage(named: "image30.png")!]


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

    let screenSize: CGRect = UIScreen.mainScreen().bounds
    let screenWidth = screenSize.width
    //let screenHeight = screenSize.height

    let numWidth: CGFloat = 3
    let numHeight: CGFloat = 10
    self.scrollView.frame.size.width = screenWidth
    let width: CGFloat = (self.scrollView.frame.size.width - (numWidth + 1))/3

    for var i:CGFloat = 0; i < 3; ++i{
        for var j:CGFloat = 0; j < 10; ++j {

            let image: UIImage = images[index] as UIImage!


            imageButton.setImage(image,forState:UIControlState.Normal)
            imageButton.frame = CGRectMake(width*i, width*j, width, width)
            self.scrollView.addSubview(imageButton)

            index++
        }
    }
    scrollView.contentSize.height = (width)*numHeight

Answer 1

我认为你是再次从Image创建Image。

就像

一样

imageButton.setImage(images[index],forState:UIControlState.Normal)

希望它能奏效。

或者你可以这样做：

var images = [String]?

viewDidLoad

中的

images = ["image1.png","image2.png"]
let img : UIImage = UIImage(named: images[index])!
imageButton = UIButton.buttonWithType(UIButtonType.System) as UIButton
button.frame = CGRectMake(100, 100, 100, 100)//Set your own frame
imageButton.setImage(img,forState:UIControlState.Normal)

并检查项目中必须提供的图像

Answer 2

图像需要在Assets.xcassets中作为图像集...工作v.smooth！

如何在Swift / Xcode中设置按钮的图像

2 个答案: