如何使用segues将数据传递给另一个Viewcontroller的函数？

Question

我想将数据从一个ViewController传递到另一个ViewController中。函数初始化必须从第一个视图控制器获取输入，并将其分配给goalDescription和goalTypes变量。

我执行以下操作：

第一个ViewController

 @IBAction func nextBtnPressed(_ sender: Any) { 
     if goalTextView.text != "" {
            guard let finishGoalVC = storyboard?.instantiateViewController(withIdentifier: "FinishGoalVC") as? FinishGoalVC else { return }
            finishGoalVC.initData(description: goalTextView.text!, type: goalType)            
            performSegue(withIdentifier: "finishGoalVC", sender: self)

第二个ViewController

 var goalDescription: String!
 var goalType: GoalType!  

    func initData(description: String, type: GoalType) {
        self.goalDescription = description
        self.goalType = type
    } 

我做错了什么，你会建议我做什么？

Answer 1

为了在ViewController之间适当地传递数据，您需要重写prepare(for:sender:)函数。

在您的情况下：

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
    if segue.identifier == "finishGoalVC" { //in case you have multiple segues
        if let viewController = segue.destination as? FinishGoalVC {
            viewController.goalDescription = goalTextView.text! // be careful about force unwrapping.
            viewController.goalType = type  
        }
    }
}