斯威夫特3 - UIImageView圖像得到收縮

Question

這裏是代碼，準備一個segue，然後從那個segue展開。

override func prepare(for segue: UIStoryboardSegue, sender: Any?) { 

    if segue.identifier == "toTossImageVC" { 
     let dvc = segue.destination as! TossImageViewController 
     dvc.displayedImage = tossPhoto2.image 
    } 
} 

@IBAction func unwindToTossVC(unwindSegue: UIStoryboardSegue) { 

    let dvc = unwindSegue.source as! TossImageViewController 
    self.tossPhoto2.image = dvc.displayedImage 
} 

如可以看到的，我傳遞到目的地VC的圖像中的準備，然後我檢索該圖像的更新版本中（用戶可以標記在目的地VC圖像）放鬆的方法。

self.tossPhoto2是一個UIImage對象，它的contentMode在Interface Builder中設置爲scaleToFill。我的問題是，當我放鬆並將tossPhoto2的圖像分配給dvc.displayedImage時，它會變得非常縮小。之前segueing和標記的圖像：

BeforePhotoFine

然後，當我們標註與標籤的照片後返回到這個VC，這裏的後可怕的縮水照片：

AfterPhotoShrunk

搜索StackOverflow的後和其他地方几個小時，解決這個問題的最好建議是將contentMode設置爲.scaleAspectFit，但這不起作用（並且我希望將它作爲InterfaceToFill在Interface Builder中定義）。

任何想法，爲什麼發生這種情況，我該如何解決這個問題？這是TossImageViewController中的代碼，如果它有幫助的話，但我不明白我可能會無意中縮小圖像。這可以允許用戶添加標籤（實現爲UILabels）到圖像上。

class TossImageViewController: UIViewController, UINavigationControllerDelegate, UIGestureRecognizerDelegate { 
@IBOutlet var tossImage: UIImageView! 
var displayedImage: UIImage! 
let ac = UIAlertController(title: "Select Toss Type", message: nil, preferredStyle: .actionSheet) 
var selectedTossType = String() 
var touchPoint: CGPoint! 


override func viewDidLoad() { 
    super.viewDidLoad() 
    tossImage.image = displayedImage 

    self.tabBarController?.tabBar.isHidden = true 

    let gestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(handleTap)) 
    self.view.addGestureRecognizer(gestureRecognizer) 

    // Set up the action sheet picker 
    let cancelAction = UIAlertAction(title: "Cancel", style: .cancel, handler: nil) 
    ac.addAction(cancelAction) 
    let trashAction = UIAlertAction(title: "Trash", style: .destructive, handler: {(action) -> Void in 
     self.selectedTossType = "Trash" 
     // Write the selected toss type where the tap happened 
     self.displayedImage = self.textToImage(drawText: self.selectedTossType as NSString, inImage: self.displayedImage, atPoint: self.touchPoint, labelWidth: 80) 
     print("Trash tag") 
    }) 
    ac.addAction(trashAction) 
    let sinkAction = UIAlertAction(title: "Sink Disposal", style: .destructive, handler: {(action) -> Void in 
     self.selectedTossType = "Sink Disposal" 
     // Write the selected toss type where the tap happened 
     self.displayedImage = self.textToImage(drawText: self.selectedTossType as NSString, inImage: self.displayedImage, atPoint: self.touchPoint, labelWidth: 120) 
    }) 
    ac.addAction(sinkAction) 
    let saveAction = UIAlertAction(title: "Save for Later", style: .destructive, handler: {(action) -> Void in 
     self.selectedTossType = "Save for Later" 
     // Write the selected toss type where the tap happened 
     self.displayedImage = self.textToImage(drawText: self.selectedTossType as NSString, inImage: self.displayedImage, atPoint: self.touchPoint, labelWidth: 140) 
    }) 
    ac.addAction(saveAction) 
    let animalAction = UIAlertAction(title: "Animal", style: .destructive, handler: {(action) -> Void in 
     self.selectedTossType = "Animal" 
     // Write the selected toss type where the tap happened 
     self.displayedImage = self.textToImage(drawText: self.selectedTossType as NSString, inImage: self.displayedImage, atPoint: self.touchPoint, labelWidth: 80) 
    }) 
    ac.addAction(animalAction) 
    let sharingAction = UIAlertAction(title: "Sharing", style: .destructive, handler: {(action) -> Void in 
     self.selectedTossType = "Sharing" 
     // Write the selected toss type where the tap happened 
     self.displayedImage = self.textToImage(drawText: self.selectedTossType as NSString, inImage: self.displayedImage, atPoint: self.touchPoint, labelWidth: 80) 
    }) 
    ac.addAction(sharingAction) 
    let compostAction = UIAlertAction(title: "Compost", style: .destructive, handler: {(action) -> Void in 
     self.selectedTossType = "Compost" 
     // Write the selected toss type where the tap happened 
     self.displayedImage = self.textToImage(drawText: self.selectedTossType as NSString, inImage: self.displayedImage, atPoint: self.touchPoint, labelWidth: 80) 
    }) 
    ac.addAction(compostAction) 

} 

override func viewWillDisappear(_ animated: Bool) { 
    self.tabBarController?.tabBar.isHidden = false 
} 

@IBAction func cancel(_ sender: Any) { 
    navigationController!.popViewController(animated: true) 
} 

func textToImage(drawText text: NSString, inImage image: UIImage, atPoint point: CGPoint, labelWidth: CGFloat) -> UIImage { 

    let label = UILabel(frame: CGRect(x: (point.x - labelWidth/2), y: point.y, width: labelWidth, height: 20)) 
    label.textColor = .red 
    label.shadowColor = .yellow 
    label.text = text as String 
    label.textAlignment = .center 
    self.view.addSubview(label) 

    let scale = UIScreen.main.scale 
    UIGraphicsBeginImageContextWithOptions(image.size, false, scale) 
    view.layer.render(in: UIGraphicsGetCurrentContext()!) 
    let taggedImage = UIGraphicsGetImageFromCurrentImageContext() 
    UIGraphicsEndImageContext() 

    return taggedImage! 
} 

Answer 1

確定 - 它看起來像這樣的問題......

你必須在你的UIImageViewTossImageViewController - 我不知道它的大小，但讓我們說這是300×300。您設置了.image = displayedImage。到目前爲止，這麼好......你看到你的圖像縮放以適應屏幕。

接下來，用戶交互之後，你叫textToImage(...)，我猜你正在努力文本繪製到原始圖像？如果是這樣，那不是發生了什麼事。

相反，你要添加UILabel到self.view，創造3000 x 2002圖形上下文，然後返回UIGraphicsGetImageFromCurrentImageContext() ...但是，圖像是當前視圖 - 這也許是750 x 1334和坐在的的左上角語境。

你需要做的是，無論是：

一）創建一個3000 x 2002的UIView，在一個UIImageView添加圖像作爲這一觀點的子視圖，然後添加的UILabel（尺寸相對於大的圖像）作爲另一個子視圖。然後從得到上下文的圖片。或...

b）使用Context和圖像drawInRect和字符串drawInRect函數。

這個職位有一些討論和解決方案（包括對象 - 和SWIFT）：How to write text on image in Objective-C (iOS)?