How to show image from url in ios swift

Question

I am trying to load image from url in my ios app swift. I have written following code.

 let imageURL =  minHost + "\(userData["profileImage"])"
 let url = URL(string: imageURL)!
 let imageData = try? Data(contentsOf: url)
 profileImage.image = UIImage(data: imageData!)

Now imageURL is having proper url, but imageData receives nil and because of this, last line through an error Fatal error: Unexpectedly found nil while unwrapping an Optional value

score 2 · Answer 1 · answered May 22 '19 at 09:16

Instead of fetching image using Data(contentsOf:) method, use URLSession to perform network calls.

let imageURL =  minHost + "\(userData["profileImage"])"

if let url = URL(string: imageURL) {
    URLSession.shared.dataTask(with: url) {[weak self] (data, urlResponse, error) in
        if let data = data {
            DispatchQueue.main.async {
                self?.profileImage.image = UIImage(data: imageData)
            }
        }
    }.resume()
}

Important Note: Avoid using forced unwrapping (!) unnecessarily. It might result in unwanted app crashes. Instead use guard or if-let to unwrap optionals.

score 1 · Answer 2 · answered May 22 '19 at 09:14

1

Try this at Playground. Loading image from the URL takes some time, and need to be executed at another Thread, different from the main thread.

import UIKit

let url = URL(string: "https://cdn.arstechnica.net/wp-content/uploads/2018/06/macOS-Mojave-Dynamic-Wallpaper-transition.jpg")!
var image = UIImage()

DispatchQueue.global().async {
    if let data = try? Data(contentsOf: url) {
        DispatchQueue.main.async {
            image = UIImage(data: data)!
        }
    }
}

image

answered May 22 '19 at 09:14

Abjox

579
1
4
14

yoyo. It works! I have tested :)) – Volodymyr May 22 '19 at 09:36
Please, mark the answer as answered if it helped!) – Abjox May 22 '19 at 09:43
You are strongly discouraged from loading data from a remote URL with synchronous `Data(contentsOf` API even on a background thread. – vadian May 22 '19 at 12:28

score 0 · Answer 3 · answered May 22 '19 at 09:02

you can try like this:

        let url = URL(string: "image url here")
        if url != nil {
            DispatchQueue.global().async { [weak self] in
                if let data = try? Data(contentsOf: url!) {
                    if let image = UIImage(data: data) {
                        DispatchQueue.main.async {

                            self.profileImage.image = image

                        }
                    }
                }
            }
        }

score 0 · Answer 4 · answered May 22 '19 at 09:05

0

Try This

let url = URL(string:imageURL)
if let data = try? Data(contentsOf: url!)
{
    profileImage.image = UIImage(data: data, scale: 1.0)!
}

answered May 22 '19 at 09:05

steveSarsawa

1,559
2
14
31

score 0 · Answer 5 · answered May 22 '19 at 09:07

Never do the downloading task on main thread. if you do, you will not able to access components in current visible screens properly. It should be always on the background thread.

    if let url = URL(string: "https://....") {

        DispatchQueue.global(qos: .background).async { 

            if let data = try? Data(contentsOf: url) {

                if let image = UIImage(data: data) {

                    DispatchQueue.main.async {

                        self.profileImage.image = image
                    }
                }
            }
        }
    }

*Never do the downloading* with `Data(contentsOf:)` not even on a background thread — vadian, May 22 '19 at 12:29

How to show image from url in ios swift

5 Answers5