相機無響應

Question

請檢查我的代碼，我沒有任何錯誤，但是當我打開視圖控制器時，相機無法啟動，只有黑屏，甚至沒有按鈕也沒有出現。

import UIKit
import AVFoundation

class CameraViewController: UIViewController,UIImagePickerControllerDelegate,UINavigationControllerDelegate {


let picker = UIImagePickerController()
@IBOutlet weak var myImageView: UIImageView!
@IBOutlet weak var cameraView: UIView!

    @IBAction func photoLibrary(_ sender: UIBarButtonItem) {

    picker.allowsEditing = false
    picker.sourceType = .photoLibrary
    picker.mediaTypes = UIImagePickerController.availableMediaTypes(for: .photoLibrary)!
    picker.modalPresentationStyle = .popover
    present(picker, animated: true, completion: nil)
    picker.popoverPresentationController?.barButtonItem = sender
}

@IBAction func shootPhoto(_ sender: UIBarButtonItem) {

    if UIImagePickerController.isSourceTypeAvailable(.camera) {
        picker.allowsEditing = false
        picker.sourceType = UIImagePickerControllerSourceType.camera
        picker.cameraCaptureMode = .photo
        picker.modalPresentationStyle = .fullScreen
        present(picker,animated: true,completion: nil)

    } else {
        noCamera()
    }
}
func noCamera(){
    let alertVC = UIAlertController(
        title: "No Camera",
        message: "Sorry, this device has no camera",
        preferredStyle: .alert)
    let okAction = UIAlertAction(
        title: "OK",
        style:.default,
        handler: nil)
    alertVC.addAction(okAction)
    present(
        alertVC,
        animated: true,
        completion: nil)
}
override func viewDidLoad() {
    super.viewDidLoad()
    picker.delegate = self
}

//MARK: - Delegates
private func imagePickerController(_ picker: UIImagePickerController,
                           didFinishPickingMediaWithInfo info: [String : AnyObject])
{
    var  chosenImage = UIImage()
    chosenImage = info[UIImagePickerControllerOriginalImage] as! UIImage //2
    myImageView.contentMode = .scaleAspectFit //3
    myImageView.image = chosenImage //4
    dismiss(animated:true, completion: nil) //5
}
func imagePickerControllerDidCancel(_ picker: UIImagePickerController) {
    dismiss(animated: true, completion: nil)
}

 }

我只能看到全黑的屏幕，甚至Swift也沒有提示。 我不知道現在該怎么辦。

Answer 1

當您尚未設置初始ViewController時，就會發生這種情況。 請確保要首先加載的ViewController在情節提要中設置為初始ViewController。