iOS 7 Programming Cookbook

1.22. Displaying Images with UIImageView

Problem

You would like to display images to your users on your app’s UI.

Solution

Use the UIImageView class.

Discussion

The UIImageView is one of the least-complicated classes in the iOS SDK. As you know, an image view is responsible for displaying images. There are no tips or tricks involved. All you have to do is instantiate an object of type UIImageView and add it to your views. Now, I have a picture of a MacBook Air, and I would like to display it in an image view. Let’s start with our view controller’s implementation file:

#import "ViewController.h"

@interface ViewController ()
@property (nonatomic, strong) UIImageView *myImageView;
@end

@implementation ViewController

Go ahead and instantiate the image view and place the image in it:

- (void)viewDidLoad{
    [super viewDidLoad];

    UIImage *macBookAir = [UIImage imageNamed:@"MacBookAir"];
    self.myImageView = [[UIImageView alloc] initWithImage:macBookAir];
    self.myImageView.center = self.view.center;
    [self.view addSubview:self.myImageView];

}

Now if we run the app, we will see something similar to Figure 1-60.

Figure 1-60. An image view that is too big to fit on the screen

I should mention that the MacBook Air image that I’m loading into this image view is 980×519 pixels, and as you can see, it certainly doesn’t fit into the iPhone screen. So how do we solve this problem? First, we need to make sure that we ...