使用Swift，我试图为一个简单的动画创建一个UIImage对象array.上下文帮助animationImages读，"数组必须包含UI图像对象."
我试图按如下方式创建上述数组，但似乎无法获得正确的语法:
var logoImages: UIImage[]
logoImages[0] = UIImage(name: "logo.png")
这引发了:
然后我试着
var logoImages = []
logoImages[0] = UIImage(named: "logo.png")
它抛出:
我查看了这里的文档，但上下文不一样:
你有两个问题(而且没有正则表达式！)
var logoImages: [UIImage] = []
或
var logoImages: Array<UIImage> = []
或
var logoImages = [UIImage]()
或
var logoImages = Array<UIImage>()
Array.append() 或 some of the equivalent syntactic sugar:logoImages.append(UIImage(named: "logo.png")!)
或
logoImages += [UIImage(named: "logo.png")!]
或
logoImages += [UIImage(named: "logo.png")!, UIImage(named: "logo2.png")!]
您需要附加到数组中，因为(摘录from docs):
You can’t use subscript syntax to append a new item to the end of an array. If you try to use subscript syntax to retrieve 或 set a value f或 an index that is outside of an array’s existing bounds, you will trigger a runtime err或. However, you can check that an index is valid bef或e using it, by comparing it to the array’s count property. Except when count is 0 (meaning the array is empty), the largest valid index in an array will always be count - 1, because arrays are indexed from zero.
当然，如果可能的话，你可以随时简化:
var logoImage: [UIImage] = [
UIImage(named: "logo1.png")!,
UIImage(named: "logo2.png")!
]
edit:请注意，UIImage现在有一个"failable" initializer，这意味着它返回一个可选值.我已经更新了所有代码位，以反映这一变化以及对数组语法的变化.