CODEWITHSUNDEEP
iosswiftuiimageviewcore-graphics
Jamil
Jamil

Reputation: 940

How to add image to UIImageView?

I'm trying to add image to UIImageView, but after I do it UIImageView is nil. Here's my code:

    class ViewController: UIViewController {

    @IBOutlet var myView: UIView!
    @IBOutlet weak var testImg: UIImageView!
    override func viewDidLoad() {
        super.viewDidLoad()
        UIGraphicsBeginImageContext(CGSize(width: 500,height: 500))
                var path = UIBezierPath()
        path.lineWidth = 1.0
        path.moveToPoint(CGPoint(x: 150, y: 150))
        var x = 151
        for ;x<300;x++
        {
            path.addLineToPoint(CGPoint(x: x, y: x))
            path.moveToPoint(CGPoint(x: x, y: x))
        }
        path.stroke()
        let img = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
                testImg = UIImageView(image: img)
        testImg.frame = CGRect(x: 0,y: 0,width: 500,height: 500)
        myView.addSubview(testImg)
        // Do any additional setup after loading the view, typically from a nib.
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }
}

When I try to set frame for UIImageView, I got this error:

fatal error: unexpectedly found nil while unwrapping an Optional value

Probably, i don't create image correctly.

UPDATE

testImg = UIImageView(image: img)

This line of code overwrites IBOutlet of UIImageView, removing it and doing simply testImg.image = img fixed problem.

Upvotes: 4

Views: 12326

Answers (3)

pedrouan
pedrouan

Reputation: 12910

Simply:

if let image = img {
    // you don't have to instantiate an imageView again, IBOutlet handles it for you    
    testImg.image = image
    print("Works")
    // if you don't see this output in your debug console, the condition never succeeds and an img is really nil
}

Upvotes: 0

xmhafiz
xmhafiz

Reputation: 3538

The error should be related to the way you push or present the ViewController. Seems the outlet is not created yet when you show or present it. Should use instantiateViewControllerWithIdentifier as below example

let viewController = self.storyboard?.instantiateViewControllerWithIdentifier("YourStoryBoardId")
self.navigationController?.pushViewController(viewController!, animated: true)

Upvotes: 0

Lankan
Lankan

Reputation: 151

Easy way : Drag and drop that image to your file view/project navigator on Xcode.

Select the image view - Then attribute inspect - Under image - Select the file name of the image you wish to load.

Enjoy the drags and drops whenever you can.

Hardway: 

if let filePath = Bundle.main.path(forResource: "imageName", ofType:     "jpg"), let image = UIImage(contentsOfFile: filePath) {    imageView.contentMode = .scaleAspectFit
    imageView.image = image
}

Upvotes: 2

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