如何使用平移，旋转和捏手势编辑后保存UIImage

Question

我试图使用UIPanGesture，UIRotateGesture和UIPinchGesture来实现编辑图像。编辑完成后，我希望保存已编辑的UIImage。

我完成了编辑图像功能。

但我不知道如何保存完全像本机iOS相机应用程序一样完美。

Pan手势工作正常。

我的问题是旋转和缩放。

如何设置UIImage的中心定位点？

当我从转换信息保存的UIImage然后UIImage的结果看起来是不同的，因为旋转和缩放，那么它总是采用基于（0,0）

@IBAction func showEditedImage(_ sender: Any) { 


     let image = preview.image! 
     var drawingRect : CGRect = CGRect.zero 
     drawingRect.size = preview.frame.size 

     let scale = transformedImg.frame.width/(preview.image?.size.width)! 
     let height = (preview.image?.size.height)! * scale 

     UIGraphicsBeginImageContextWithOptions(CGSize(width: transformedImg.frame.width, height: height), false, 0) 

     let context = UIGraphicsGetCurrentContext() 
     context!.concatenate(preview.transform) 

     image.draw(in: CGRect(x: 0, y: 0, width: transformedImg.frame.width, height: height)) 
     resultsImg = UIGraphicsGetImageFromCurrentImageContext() 
     UIGraphicsEndImageContext(); 

     transformedImg.image = resultsImg 
    } 

这里是我的所有代码。

import UIKit 

class ViewController: UIViewController { 


    @IBOutlet weak var preview: UIImageView! 
    @IBOutlet weak var frame: UIView! 
    @IBOutlet weak var transformedImg: UIImageView! 

    //save edited image 
    var resultsImg : UIImage! 

    override func viewDidLoad() { 

     resultsImg = UIImage() 
     super.viewDidLoad() 
    } 


     @IBAction func showEditedImage(_ sender: Any) { 


    let image = preview.image! 
    var drawingRect : CGRect = CGRect.zero 
    drawingRect.size = preview.frame.size 

    let scale = transformedImg.frame.width/(preview.image?.size.width)! 
    let height = (preview.image?.size.height)! * scale 

    UIGraphicsBeginImageContextWithOptions(CGSize(width: transformedImg.frame.width, height: height), false, 0) 

    let context = UIGraphicsGetCurrentContext() 
    context!.concatenate(preview.transform) 

    image.draw(in: CGRect(x: 0, y: 0, width: transformedImg.frame.width, height: height)) 
    resultsImg = UIGraphicsGetImageFromCurrentImageContext() 
    UIGraphicsEndImageContext(); 

    transformedImg.image = resultsImg 
} 

    @IBAction func pinchaction(_ sender: UIPinchGestureRecognizer) { 

     preview.transform = preview.transform.scaledBy(x: sender.scale, y: sender.scale) 

     sender.scale = 1 
    } 

    @IBAction func rotateaction(_ sender: UIRotationGestureRecognizer) { 

     let rotate = sender.rotation 
     preview.transform = preview.transform.rotated(by: rotate) 


     sender.rotation = 0 

    } 

    @IBAction func panaction(_ sender: UIPanGestureRecognizer) { 

     let points = sender.translation(in: self.frame) 
     preview.transform = preview.transform.translatedBy(x: points.x, y: points.y) 

     let translatedCenter = CGPoint(x:self.frame.center.x + points.x, y:self.frame.center.y + points.y) 

     sender.setTranslation(CGPoint.zero, in: self.frame) 

    } 



} 

环境：XCode9 +斯威夫特4

更新2017年10月14日

我解决我的问题

@IBAction func showEditedImage(_ sender: Any) { 

     let image = preview.image! 
     var drawingRect : CGRect = CGRect.zero 
     drawingRect.size = preview.frame.size 

     let scale = transformedImg.frame.width/(preview.image?.size.width)! 
     let height = (preview.image?.size.height)! * scale 


     UIGraphicsBeginImageContextWithOptions(CGSize(width: transformedImg.frame.width, height: height), false, 0) 

     let context = UIGraphicsGetCurrentContext() 

     //Set Center Position before Scale, Rotate Image 
     context?.translateBy(x: transformedImg.frame.width/2, y: height/2) 

     //Applied Translate, Scale, Rotate 
     context!.concatenate(preview.transform) 

     context?.translateBy(x: -(transformedImg.frame.width/2), y: -(height/2)) 

     image.draw(in: CGRect(x: 0, y: 0, width: transformedImg.frame.width, height: height)) 
     resultsImg = UIGraphicsGetImageFromCurrentImageContext() 
     UIGraphicsEndImageContext(); 

     transformedImg.image = resultsImg 
    } 

Answer 1

我有一个名为MyView的透明背景UIIView和我添加的UIImageView到MyView的作为子视图，然后我申请UIRotationGestureRecognizer上MyView的使这里旋转我的形象是UIRotationGestureRecognizer我@IBAction FUNC ....

@IBAction func rotateGesture(sender: UIRotationGestureRecognizer) { 
    if let view = sender.view { 
     view.transform = CGAffineTransformRotate(view.transform, sender.rotation) 
     sender.rotation = 0 
    } 
} 

Answer 2

我实现雨燕2.3这个功能，所以你可以在Swift 4中使用它。

fun SaveImage() 
{ 
    if myImageView != nil 
    { 
     // You should hide here your Buttons,Labels, etc. 

    let layer = UIApplication.sharedApplication().keyWindow!.layer 
    let scale = UIScreen.mainScreen().scale 
    UIGraphicsBeginImageContextWithOptions(layer.frame.size, false, scale); 

    layer.renderInContext(UIGraphicsGetCurrentContext()!) 
    let screenshot = UIGraphicsGetImageFromCurrentImageContext() 
    UIGraphicsEndImageContext() 

     // Now here you can UnHide(Show) your Buttons,Labels,etc 
    UIImageWriteToSavedPhotosAlbum(screenshot, nil, nil, nil) 
    let alert = UIAlertView(title: "Alert !!", 
     message: "Your image has been saved to Photo Library", 
     delegate: nil, 
     cancelButtonTitle: "OK") 
    alert.show() 

    } 
    else 
    { 
     let alert = UIAlertView(title: "Alert !!", 
      message: "Please first Select/Capture Image", 
      delegate: nil, 
      cancelButtonTitle: "OK") 
     alert.show() 
    } 

}