ios - 错误？在IBAction按钮内读取变量

我有一个IBAction，需要从变量中读取。但是，将变量放在viewDidLoad之外时，会收到错误消息


  无法在属性初始化程序中使用实例成员“ animal”；属性初始化程序在“自我”可用之前运行


我的代码如下。当我将变量移回viewDidLoad内部时，错误指出未声明animalName

var animalName = (String(format: "%03d", animal.speciesId!))

@IBAction func megaKeyIBO(_ sender: Any) {
    animalName = (String(format: "%03d", animal.speciesId!)) + "-merg"
}

override func viewDidLoad() {
    super.viewDidLoad()

    //variable was originally here before moving to top
    var animalName = (String(format: "%03d", animal.speciesId!))
}

最佳答案

发生这种情况是因为您试图在属性animal.speciesId之前初始化animalName！已初始化。一种简单的解决方法是：

var animalName: String!

@IBAction func megaKeyIBO(_ sender: Any) {
    animalName = (String(format: "%03d", animal.speciesId!)) + "-merg"
}

override func viewDidLoad() {
    super.viewDidLoad()

    // Initialize on viewDidLoad
    animalName = (String(format: "%03d", animal.speciesId!))
}

关于ios - 错误？在IBAction按钮内读取变量，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/41433042/