UIImageView aspect fit and center

Question

I have an image view  declared programmatically  and I am setting its image  also programmatically   However  I find myself unable to set the image to both fit the aspect and align centre to the image view   In other words  I want the image to    Scale down to fit the aspect  if the image is large  Centre but not scale up  if the image is small    How do I get that

User · Answer

This subclass uses center if the image is not larger than the view, otherwise it scales down. I found this useful for a UIImageView that changes the size.

The image it displays is smaller than the view for large sizes, but larger than the view for small sizes. I want it only to scale down, but not up.

class CenterScaleToFitImageView: UIImageView {
    override var bounds: CGRect {
        didSet {
            adjustContentMode()
        }
    }

    override var image: UIImage? {
        didSet {
            adjustContentMode()
        }
    }

    func adjustContentMode() {
        guard let image = image else {
            return
        }
        if image.size.width > bounds.size.width ||
            image.size.height > bounds.size.height {
            contentMode = .ScaleAspectFit
        } else {
            contentMode = .Center
        }
    }
}

User · Answer

You can achieve this by setting content mode of image view to UIViewContentModeScaleAspectFill   Then use following method method to get the resized uiimage object   -  UIImage  setProfileImage  UIImage   imageToResize onImageView  UIImageView   imageView       CGFloat width   imageToResize size width      CGFloat height   imageToResize size height      float scaleFactor      if width  gt  height                scaleFactor   imageView frame size height   height            else               scaleFactor   imageView frame size width   width             UIGraphicsBeginImageContextWithOptions CGSizeMake width   scaleFactor  height   scaleFactor   NO  0 0        imageToResize drawInRect CGRectMake 0  0  width   scaleFactor  height   scaleFactor        UIImage  resizedImage   UIGraphicsGetImageFromCurrentImageContext        UIGraphicsEndImageContext         return resizedImage      Edited Here  Swift Version   func setProfileImage imageToResize  UIImage  onImageView  UIImageView  - gt  UIImage       let width   imageToResize size width     let height   imageToResize size height      var scaleFactor  CGFloat      if width  gt  height                scaleFactor   onImageView frame size height   height            else               scaleFactor   onImageView frame size width   width             UIGraphicsBeginImageContextWithOptions CGSizeMake width   scaleFactor  height   scaleFactor   false  0 0      imageToResize drawInRect CGRectMake 0  0  width   scaleFactor  height   scaleFactor       let resizedImage   UIGraphicsGetImageFromCurrentImageContext       UIGraphicsEndImageContext        return resizedImage

User · Answer

let bannerImageView   UIImageView    bannerImageView contentMode    ScaleAspectFit  bannerImageView frame   CGRectMake cftX  cftY  ViewWidth  scrollHeight

User · Answer

For people looking for UIImage resizing    implementation UIImage  Resize   -  UIImage   scaledToSize  CGSize size       UIGraphicsBeginImageContextWithOptions size  NO  0 0f        self drawInRect CGRectMake 0 0f  0 0f  size width  size height        UIImage  image   UIGraphicsGetImageFromCurrentImageContext        UIGraphicsEndImageContext        return image     -  UIImage   aspectFitToSize  CGSize size       CGFloat aspect   self size width   self size height      if  size width   aspect  lt   size height                return  self scaledToSize CGSizeMake size width  size width   aspect          else           return  self scaledToSize CGSizeMake size height   aspect  size height             -  UIImage   aspectFillToSize  CGSize size       CGFloat imgAspect   self size width   self size height      CGFloat sizeAspect   size width size height       CGSize scaledSize           if  sizeAspect  gt  imgAspect       increase width  crop height             scaledSize   CGSizeMake size width  size width   imgAspect             else      increase height  crop width             scaledSize   CGSizeMake size height   imgAspect  size height                 UIGraphicsBeginImageContextWithOptions size  NO  0 0f       CGContextRef context   UIGraphicsGetCurrentContext        CGContextClipToRect context  CGRectMake 0  0  size width  size height         self drawInRect CGRectMake 0 0f  0 0f  scaledSize width  scaledSize height        UIImage  image   UIGraphicsGetImageFromCurrentImageContext        UIGraphicsEndImageContext        return image      end

User · Answer

I solved this problem like this    setImage to UIImageView  with UIViewContentModeScaleAspectFit  get imageSize  CGSize imageSize   imageView image size  UIImageView resize   imageView sizeThatFits imageSize  move position where you want    I wanted to put UIView on the top center of UICollectionViewCell  so  I used this function   -  void setImageToCenter  UIImageView   imageView       CGSize imageSize   imageView image size       imageView sizeThatFits imageSize       CGPoint imageViewCenter   imageView center       imageViewCenter x   CGRectGetMidX self contentView frame        imageView setCenter imageViewCenter       It works for me

User · Answer

Swift  yourImageView contentMode    center   You can use the following options to position your image    scaleToFill scaleAspectFit      contents scaled to fit with fixed aspect  remainder is transparent redraw    redraw on bounds change  calls -setNeedsDisplay  center    contents remain same size  positioned adjusted  top bottom left right topLeft topRight bottomLeft bottomRight

User · Answer

your imageview setContentMode UIViewContentModeCenter

User · Answer

In swift language we can set content mode of UIImage view like following as    let newImgThumb   UIImageView frame  CGRect x  10  y  10  width  100  height  100   newImgThumb contentMode    scaleAspectFit

User · Answer

Just pasting the solution   Just like  manohar said  imageView contentMode   UIViewContentModeCenter  if  imageView bounds size width  gt    UIImage  imagesArray i   size width  amp  amp  imageView bounds size height  gt    UIImage  imagesArray i   size height           imageView contentMode   UIViewContentModeScaleAspectFit      solved my problem

User · Answer

Updated answer  When I originally answered this question in 2014  there was no requirement to not scale the image up in the case of a small image   The question was edited in 2015   If you have such a requirement  you will indeed need to compare the image s size to that of the imageView and use either UIViewContentModeCenter  in the case of an image smaller than the imageView  or UIViewContentModeScaleAspectFit in all other cases   Original answer  Setting the imageView s contentMode to UIViewContentModeScaleAspectFit was enough for me  It seems to center the images as well  I m not sure why others are using logic based on the image  See also this question  iOS aspect fit and center

[ios] UIImageView aspect fit and center

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