swift - 快速将数据传递给变量

Question

我想将按钮标签分配给变量。然后我尝试将此数据发送到 SecondViewController 并将其分配给 var。

@IBAction func goToProducts(_ sender: UIButton) {
    
    performSegue(withIdentifier: TextStrings.ProfileAluVC.goToProducts, sender: self)
    categoryNumber = sender.tag }

将数据传递给 ProductsViewController

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
    if segue.identifier == "goToProducts" {
        let destinationController = segue.destination as! ProductsViewController
        destinationController.categoryNumb = categoryNumber
    }
}

在 ProductsViewController 中，我创建了 var，但没有此数据。我打印这个变量并得到这个:

categoryNumber: 373

categoryNumb: Optional(24)

你能告诉我我该怎么做吗？

Answer 1

需要在performSegue之前先赋值

categoryNumber = sender.tag  
performSegue(withIdentifier: TextStrings.ProfileAluVC.goToProducts, sender: self)

---

或使用sender

performSegue(withIdentifier: TextStrings.ProfileAluVC.goToProducts, sender: sender.tag)  

将数据传递给 ProductsViewController

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
    if segue.identifier == "goToProducts" {
        let destinationController = segue.destination as! ProductsViewController
        destinationController.categoryNumb = sender as! Int
    }
}