ios - 如何使用 UIImagePicker/Swift 调整照片大小

Question

在相机快速拍摄照片后，我无法调整照片大小。目前，我的场景中有一个 100 x 100 的 ImageView (用于个人资料照片)，但是当我运行该应用程序时，使用相机后照片永远不会显示。这是我的代码。我缺少的是:

@IBAction func employeePhotoButton(sender: AnyObject) {

    if UIImagePickerController.isSourceTypeAvailable(UIImagePickerControllerSourceType.Camera) {
        var imagePicker = UIImagePickerController()
        imagePicker.delegate = self
        imagePicker.sourceType = UIImagePickerControllerSourceType.Camera;
        imagePicker.allowsEditing = false
        self.presentViewController(imagePicker, animated: true, completion: nil)

        func resizeImage(image: UIImage, newWidth: CGFloat) -> UIImage {

            let scale = newWidth / image.size.width
            let newHeight = image.size.height * scale
            UIGraphicsBeginImageContext(CGSizeMake(newWidth, newHeight))
            image.drawInRect(CGRectMake(0, 0, newWidth, newHeight))
            let newImage = UIGraphicsGetImageFromCurrentImageContext()
            UIGraphicsEndImageContext()

            return newImage
        }

        func imagePickerController(picker: UIImagePickerController, didFinishPickingImage image: UIImage!, editingInfo: [NSObject : AnyObject]!) {

            employeePhoto.image = resizeImage(image!, newWidth: 100)

            self.dismissViewControllerAnimated(true, completion: nil);
        }


    }
}

Answer 1

尝试这样的事情(注意这是使用 Swift3 语法):

// your IBAction could look something like this
@IBAction func employeePhotoButton(sender: AnyObject) 
{
    if UIImagePickerController.isSourceTypeAvailable(UIImagePickerControllerSourceType.Camera) 
    {
        showImagePicker(.camera)
    }
    else
    {
        print("camera not available")
    }
}

// your function in your view controller to display the image picker with whichever
// source type you want, check for source type availability before calling
func showImagePicker(sourceType:UIImagePickerControllerSourceType)
{
    // instantiates and configures class var
    self.imagePickerController = UIImagePickerController.init()
    self.imagePickerController?.modalPresentationStyle = .currentContext
    self.imagePickerController?.sourceType = sourceType
    self.imagePickerController?.delegate = self
    self.imagePickerController?.allowsEditing = false

    // present controller
    self.present(self.imagePickerController!, animated: true, completion: nil)
}


// Image picker delegate function
func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any])
{
    // dismiss the picker view controller
    print("Selected media with info: \(info)")
    self.dismiss(animated: true, completion: nil)

    // no longer need this so nil out now
    self.imagePickerController = nil

    // check our image is valid
    guard (info[UIImagePickerControllerOriginalImage] != nil) else {
        print("No image found to load...")
        return
    }

    // sets our 'selectedImg' class var for use elsewhere if needed
    selectedImg = info[UIImagePickerControllerOriginalImage] as? UIImage

    // verify the image is not nil
    guard selectedImg != nil  else {
        print("selected image is nil")
        return
    }

    // resize our selected image
    let resizedImage = selectedImg.convert(toSize:CGSize(width:100.0, height:100.0), scale: UIScreen.main.scale)

    // TODO: whatever you want to do with your resized image
    employeePhoto.image = resizedImage
}


extension UIImage
{
    // convenience function in UIImage extension to resize a given image
    func convert(toSize size:CGSize, scale:CGFloat) ->UIImage
    {
        let imgRect = CGRect(origin: CGPoint(x:0.0, y:0.0), size: size)
        UIGraphicsBeginImageContextWithOptions(size, false, scale)
        self.draw(in: imgRect)
        let copied = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()

        return copied!
    }
}