Question

我的ViewController上有一个名为 Validate（）的函数，在另一个控制器的文本字段后调用此函数 DidEndEditing（） 但是当我要启用按钮时，它会给我一个错误找到nil，同时展开可选值 ..

ViewController：

  func validate() {

    var txtboxcount = 0
    var txtboxcountval = 0

    let storyboard = UIStoryboard(name: "Main", bundle: nil)
    let vc = storyboard.instantiateViewController(withIdentifier: "QuestionsPage") as! QuestionsViewController


    var offer = NeedPaymentViewController.details.offer
    var address = NeedPaymentViewController.details.address



    var qsts = QuestionsViewController.question.qsts
    var total = QuestionsViewController.question.totalqsts

    print("qsts: \(qsts) and total: \(total) and offer: \(offer) and address : \(address)")



    if(offer != "" && address != "" && qsts == total) {
      saveBtn.isEnabled = true --> **Error happens Here "Found Nil" **
      saveBtn.backgroundColor = UIColor.red
    }

另一名控制人：

   func validate() {
    let sb = UIStoryboard(name: "Main", bundle: nil)
    let vc = sb.instantiateViewController(withIdentifier: "MainNeedPage") as! NeedDetailsController;
    vc.validate()
  }

   @IBAction func offerTxtDoneEditing(_ sender: Any) {
    NeedPaymentViewController.details.offer = ""
    NeedPaymentViewController.details.address = ""

    NeedPaymentViewController.details.offer = offerTxt.text!
    NeedPaymentViewController.details.address = addressTxt.text!

    validate()
}

Answer 1

您只是实例化VC，当您调用＆＃34; vc.validate（）＆＃34;时，它在视图层次结构中不活动，因此您的saveBtn插座尚未连接，从而导致崩溃。

无论如何......你的结构似乎需要一些改变。让viewcontrollers使用委托进行通信，并将viewcontroller非特定逻辑提取到其他类。

从另一个控制器验证Textfield后，从主控制器启用按钮

1 个答案: