How to scale a UIImageView proportionally?

Question

I have a UIImageView and the objective is to scale it down proportionally by giving it either a height or width.

UIImage *image = [[UIImage alloc] initWithData:[NSData dataWithContentsOfURL:[NSURL URLWithString:@"http://farm4.static.flickr.com/3092/2915896504_a88b69c9de.jpg"]]];
UIImageView *imageView = [[UIImageView alloc] initWithImage:image]; 

//Add image view
[self.view addSubview:imageView];   

//set contentMode to scale aspect to fit
imageView.contentMode = UIViewContentModeScaleAspectFit;

//change width of frame
CGRect frame = imageView.frame;
frame.size.width = 100;
imageView.frame = frame;

The image did get resized but the position is not at the top left. What is the best approach to scaling image/imageView and how do I correct the position?

Answer 1

I've seen a bit of conversation about scale types so I decided to put together an article regarding some of the most popular content mode scaling types.

The associated image is here:

Answer 2

I used following code.where imageCoverView is UIView holds UIImageView

if (image.size.height<self.imageCoverView.bounds.size.height && image.size.width<self.imageCoverView.bounds.size.width)
{
    [self.profileImageView sizeToFit];
    self.profileImageView.contentMode =UIViewContentModeCenter
}
else
{
    self.profileImageView.contentMode =UIViewContentModeScaleAspectFit;
}

Answer 3

one can resize an UIImage this way

image = [UIImage imageWithCGImage:[image CGImage] scale:2.0 orientation:UIImageOrientationUp];

Answer 4

This works fine for me Swift 2.x:

imageView.contentMode = .ScaleAspectFill
imageView.clipsToBounds = true;

Answer 5

Set your UIimageview by scale.........

Answer 6

UIImage *image = [[UIImage alloc] initWithData:[NSData dataWithContentsOfURL:[NSURL URLWithString:@"http://farm4.static.flickr.com/3092/2915896504_a88b69c9de.jpg"]]];
UIImageView *imageView = [[UIImageView alloc] initWithImage:image]; 


//set contentMode to scale aspect to fit
imageView.contentMode = UIViewContentModeScaleAspectFit;

//change width of frame
//CGRect frame = imageView.frame;
//frame.size.width = 100;
//imageView.frame = frame;

//original lines that deal with frame commented out, yo.
imageView.frame = CGRectMake(10, 20, 60, 60);

...

//Add image view
[myView addSubview:imageView]; 

The original code posted at the top worked well for me in iOS 4.2.

I found that creating a CGRect and specifying all the top, left, width, and height values was the easiest way to adjust the position in my case, which was using a UIImageView inside a table cell. (Still need to add code to release objects)