Load an image in UIImageView and resize the container - swift

Question

I have an s3 link using which I need to load an image in UIImageView. I don't have the dimensions of image with me. I have defined mainImageView (leading and trailing constraints) in storyboard

In the code, I am loading the image using:

mainImageView.setImageWith(URL(string: ("https:" + (content?.imagePath)!)), placeholderImage: nil)

Do we have any way of resizing the container once the image loads? I want the container to take the dimensions (height and width) of the image. I heard that there is something called content wrap in Android to achieve the same. However, I am unable to find an equivalent in iOS.

Answer 1

If you are using Autolayout, you dont actually have to do much as UIImageView has an intrinsic size which makes it take the width and height of the image. In your .xib or .storyboard you need to position the image view so that it can resolve its position(horizontal and vertical). For size you can provide a default image(ow autolayout will show error).

When you will change the image at runtime, the imageview will take the size of its image.

Answer 2

You can resize the image by modifying its frame to the image's size:

mainImageView.frame = CGRect(origin: mainImageView.frame.origin, size: mainImageView.image.size)

If you are using Auto Layout, you need to modify the height and width constraints accordingly or let the layout to its job.

Answer 3

You can achieve it using:

imgView.frame = [self frameForImage:self.image inImageViewAspectFit:imgView];

function implementation:

-(CGRect)frameForImage:(UIImage*)image inImageViewAspectFit:(UIImageView*)imageView
{
    float imageRatio = image.size.width / image.size.height;
    float viewRatio = imageView.frame.size.width / imageView.frame.size.height;
    if(imageRatio < viewRatio) {
        float scale = imageView.frame.size.height / image.size.height;
        float width = scale * image.size.width;
        float topLeftX = (imageView.frame.size.width - width) * 0.5;
        return CGRectMake(topLeftX, 0, width, imageView.frame.size.height);
    } else {
        float scale = imageView.frame.size.width / image.size.width;
        float height = scale * image.size.height;
        float topLeftY = (imageView.frame.size.height - height) * 0.5;
        return CGRectMake(0, topLeftY, imageView.frame.size.width, height);
    }
}