Segue 图像到另一个视图控制器的问题

Posted 2023-03-11

【中文标题】Segue 图像到另一个视图控制器的问题

【英文标题】：Issue with Segue image to another viewcontroller

【发布时间】：2015-11-02 19:07:47

【问题描述】：

我有 2 个 VC：

第一个 VC 点击时带有 1 个按钮 >> 2 个选项 发布图像表单 cam 或 库

第二个 VC 选择的图像从 VC1 连接到第二个 VC

我试图想通这个错误没有任何成功

致命错误：在展开可选值时意外发现 nil 指着

  imageView.image=info[UIImagePickerControllerOriginalImage] as? UIImage

我将项目上传到了 Dropbox https://www.dropbox.com/s/w7blbnyac9qyxgw/segImage.zip?dl=0

VC1

    class ViewController:UIViewController,UIAlertViewDelegate,UIImagePickerControllerDelegate,UINavigationControllerDelegate,UIPopoverControllerDelegate

    @IBOutlet weak var btnClickMe: UIButton!
    @IBOutlet weak var imageView: UIImageView!
    var picker:UIImagePickerController?=UIImagePickerController()
    var popover:UIPopoverController?=nil

    override func viewDidLoad()
    
        super.viewDidLoad()
        picker!.delegate=self
        // Do any additional setup after loading the view, typically from a nib.
    

    override func didReceiveMemoryWarning() 
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    



    override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) 
        if (segue.identifier == "" ) 
            let destVC : second = segue.destinationViewController as! second
            destVC.pics = imageView.image!
        
    

    @IBAction func btnImagePickerClicked(sender: AnyObject)
    
        let alert:UIAlertController=UIAlertController(title: "Choose Image", message: nil, preferredStyle: UIAlertControllerStyle.ActionSheet)

        let cameraAction = UIAlertAction(title: "Camera", style: UIAlertActionStyle.Default)
            
                UIAlertAction in
                self.openCamera()

        
        let gallaryAction = UIAlertAction(title: "Gallary", style: UIAlertActionStyle.Default)
            
                UIAlertAction in
                self.openGallary()
        
        let cancelAction = UIAlertAction(title: "Cancel", style: UIAlertActionStyle.Cancel)
            
                UIAlertAction in

        

        // Add the actions
        picker?.delegate = self
        alert.addAction(cameraAction)
        alert.addAction(gallaryAction)
        alert.addAction(cancelAction)
        // Present the controller
        if UIDevice.currentDevice().userInterfaceIdiom == .Phone
        
            self.presentViewController(alert, animated: true, completion: nil)
        
        else
        
            popover=UIPopoverController(contentViewController: alert)
            popover!.presentPopoverFromRect(btnClickMe.frame, inView: self.view, permittedArrowDirections: UIPopoverArrowDirection.Any, animated: true)
        
    
    func openCamera()
    
        if(UIImagePickerController .isSourceTypeAvailable(UIImagePickerControllerSourceType.Camera))
        
            picker!.sourceType = UIImagePickerControllerSourceType.Camera
            self .presentViewController(picker!, animated: true, completion: nil)
        
        else
        
            openGallary()
        
    
    func openGallary()
    
        picker!.sourceType = UIImagePickerControllerSourceType.PhotoLibrary
        if UIDevice.currentDevice().userInterfaceIdiom == .Phone
        
            self.presentViewController(picker!, animated: true, completion: nil)
        
        else
        
            popover=UIPopoverController(contentViewController: picker!)
            popover!.presentPopoverFromRect(btnClickMe.frame, inView: self.view, permittedArrowDirections: UIPopoverArrowDirection.Any, animated: true)
        
    
    func imagePickerController(picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : AnyObject])
    
        picker .dismissViewControllerAnimated(true, completion: nil)
        imageView.image=info[UIImagePickerControllerOriginalImage] as? UIImage
    
    func imagePickerControllerDidCancel(picker: UIImagePickerController)
    
        print("picker cancel.")
    

第二个VC

class second: UIViewController 

var pics = UIImage()

@IBOutlet var image: UIImageView!
override func viewDidLoad() 
    super.viewDidLoad()

    if let img = UIImage(named: "pics")
    
        self.image.image = img
    

【参考方案1】：

您的故事板接线错误。

图像实际上应该设置在second 的实例而不是ViewController. 的实例上注意，崩溃发生在ViewController 而不是second

这段代码：

func imagePickerController(picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : AnyObject])

    picker .dismissViewControllerAnimated(true, completion: nil)
    imageView.image=info[UIImagePickerControllerOriginalImage] as? UIImage

正在尝试在ViewController 中设置imageView.image。如果您查看情节提要，ViewController 中没有 UIImageView。

您在ViewController 上定义imageView 的方式是导致此崩溃的原因：

@IBOutlet weak var imageView: UIImageView!

有了!，你在说，“这永远不会是零。”好吧，显然不是这样，因为因为这个 IBOutlet 没有连接到 UIImageView，所以它是 nil。因此，当您尝试访问它时，BOOM！

解决这个问题：

当用户选择图片时转到second 在second的image.imageView属性上设置选中的图片

其他建议： - 在命名中使用一致性，例如 second vs SecondViewController