Question

在我正在开发的应用程序中，我有一个图像选择器，通过单击视图控制器1上的按钮可以调用该图像选择器。选择图像后，我要将其发送到视图控制器2，以便用户可以输入有关上传之前的图片。

在下面的代码中，我可以正常工作，但是有一件事我不知道。当我选择查看控制器2时，第一个视图控制器始终闪烁到屏幕上，而不是立即选择查看控制器2。这一系列事件似乎是图像选择器被驳回->视图控制器1短暂出现->准备进行筛选->然后视图控制器2加载。

是否可以更改代码，以便在选择图像后立即进行查看控制器2的选择？如果由于取消了图像选择器而未选择图像，我想返回视图控制器1。

import UIKit
import Parse

class UserHome: UIViewController {

var newImage: UIImage?

@IBOutlet weak var welcomeLabel: UILabel!
@IBOutlet weak var imageArea: UIImageView!
@IBOutlet weak var currentUser: UIButton!
@IBAction func tapLogOut(_ sender: Any) {
    PFUser.logOut()
}
@IBAction func tapWeddingInfo(_ sender: Any) {
    opeURLFromString(urlString: weddingURL)
}
@IBAction func tapSlideShow(_ sender: Any) {
    self.performSegue(withIdentifier: "showSlideShow", sender: self)
}
@IBAction func tapAddImage(_ sender: Any) {
    print("tapped add image")
    let imagePicker = UIImagePickerController()
    imagePicker.delegate = self
    imagePicker.sourceType = .photoLibrary
    imagePicker.allowsEditing = false
    self.present(imagePicker, animated: true, completion: nil)
}
override func viewDidLoad() {
    super.viewDidLoad()
    loadPage()
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
    if segue.identifier == "showImageSubmit"{
        let vc = segue.destination as! ImageSubmit
        vc.newImage = newImage
    }
}
func loadPage() {
    print("query a database for images")
    print("load an array with those images")
    // Figure out a way to have images scroll into viewing area
    if let userEmail = PFUser.current()?.username {
        currentUser.setTitle(userEmail, for: [])
    }
    imageArea.image = UIImage(named: userHomeImage)
    welcomeLabel.text = userHomeMsg

    print ("loaded User Home")
    }
}
extension UserHome: UIImagePickerControllerDelegate, UINavigationControllerDelegate {
    public func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {

        if let image = info[UIImagePickerController.InfoKey.originalImage] as? UIImage {
            // Convert image into PFFile data type
            // self.imageArea.image = image
            newImage = image
            self.dismiss(animated: true, completion: nil)
        }
        self.performSegue(withIdentifier: "showImageSubmit", sender: self)
    }

}

Answer 1

您可以使用completion方法中的dismiss。撤消UIImagePickerController之后，下一个控制器出现

public func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {

    guard let image = info[.originalImage] as? UIImage else { 
        // dismiss(animated: true)
        return
    }
    // Convert image into PFFile data type
    // self.imageArea.image = image
    newImage = image

    dismiss(animated: true) {
        self.performSegue(withIdentifier: "showImageSubmit", sender: self)
    }
}

有没有一种方法可以控制在图像选择器完成后锁定到哪个视图控制器

1 个答案: