Question

我搜索了一下，当我运行它时，我似乎无法弄清楚为什么我的模拟器屏幕是黑色的。版权页面仍然加载，但后面的视图是黑色。我认为这可能与viewdidLoad()有关。我错了，因为我是Swift的新手。请帮我。感谢。

import UIKit

class ViewController: UIViewController, UIPickerViewDelegate, UIPickerViewDataSource {
    @IBOutlet var Picker: UIPickerView!
    @IBOutlet var Button: UIButton!
    var PlacementAnswer = 0

    var Array = ["First View Controller", "Second View Controller"]

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.

        Picker.delegate = self
        Picker.dataSource = self
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
       // Dispose of any resources that can be recreated.
    }
    func pickerView(pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String! {
        return Array [row]
    }
    func pickerView(pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
        return Array.count
    }
    func numberOfComponentsInPickerView(pickerView: UIPickerView) -> Int {
        return 1
    }
    @IBAction func Select(sender: AnyObject){

        if (PlacementAnswer == 0){
            performSegueWithIdentifier("FirstView", sender: sender)
        }else{
            performSegueWithIdentifier("SecondView", sender: sender)
        }
        return 
    }

    func pickerView(pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
        NSLog("Hello")
        PlacementAnswer = row
    }
}

Answer 1

确保故事板中的所有视图都连接到正确的控制器类，并且您已在故事板中设置了入口点视图。不幸的是，我看到几个人从故事板中删除了入口点。（小右键表示故事板中的箭头）

模拟器上的黑屏（viewDidLoad）？

1 个答案: