Question

UISegmentedControl.selectedSegmentIndex

产生错误

我尝试使用title属性而不是切换，但它没有帮助，出现了同样的错误。

当我评论整个函数并尝试打印numberOfColumnsSelector.selectedSegmentIndex时，它不会崩溃并打印出正确答案。

控制台输出：＆＃34;致命错误：在打开可选值时意外发现nil＆＃34;

我在下面评论了导致该错误的行：

import UIKit
class ViewController: UIViewController {

    //Declaring variables
    @IBOutlet weak var numberOfColumnsSelector: UISegmentedControl!        
    @IBOutlet weak var populatedPlacesSelector: UITextField!

    var numberOfColumns: Int = 0
    var populatedPlaces: [Int] = []

    // This makes those previously declared variables accessible
    func makeVariablesAccessible () -> ( size: Int, popPlacesArray: [Int] ) {
        // THE LINE BELOW IS THE PROBLEMATIC ONE
        switch numberOfColumnsSelector.selectedSegmentIndex {
        case 0:
            numberOfColumns = 2
        case 1:
            numberOfColumns = 3
        case 2:
            numberOfColumns = 4
        case 3:
            numberOfColumns = 5
        case 4:
            numberOfColumns = 6
        case 6:
            numberOfColumns = 7
        case 8:
            numberOfColumns = 8
        default:
            numberOfColumns = 2
        }

        if populatedPlacesSelector.text != "" {
            var counter = 0
            var popPlaceString = ""
            for c in populatedPlacesSelector.text!.characters {
                if c == "." {
                    populatedPlaces.append(Int(popPlaceString)!)
                    print(populatedPlaces)
                    print(popPlaceString)
                    popPlaceString = ""
                    counter++
                }
                else {
                    popPlaceString.append(c)
                }
            }
        }
        return ( numberOfColumns, populatedPlaces )
    }
}

Answer 1

我发现问题在于我要求另一个ViewController上的值，让它们无法访问，在我修复它之后，它起作用了，谢谢所有帮助过我的人。

获取错误EXC_BAD_INSTRUCTION（代码= I386_INVOP，子代码= 0x0）

1 个答案: