SDWebImage changing images while tableview scrolling

Question

There is a TableView with Cells and there is ImageView in each of them. I use SDWebImage to load images and it works fine, but when I scroll fast - I see that images in cells are changing few times before it will be right image.

Why is it happening? What should I do?

p.s. I tried use it with or without placeholder with same result

imageView.sd_setImage(with: URL(string : myImageURL), placeholderImage: UIImage(named: "default.jpg"))

score 5 · Answer 1 · answered Feb 12 '17 at 08:49

5

In your prepareForReuse() try adding:

imageView.sd_cancelCurrentImageLoad()

It will cancel the previous image downloading and then it won't happen.

Also, I would suggest using the sd_setImage with the completion block, that way you can also make sure it loads correctly.

answered Feb 12 '17 at 08:49

unkgd

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What can you recommend to check in this completion block? – moonvader Feb 12 '17 at 09:12
usually I add a fade animation to make the image appear more smoothly, when you add a fade-in transition to the image, users don't notice when you have hard image transitions, sometimes I also checked if the image matches the object (object was cleared upon a private initializer in the cell itself). But also SDWebImage's method with completion block works better. – unkgd Feb 12 '17 at 09:25

score 4 · Answer 2 · edited Oct 15 '22 at 16:31

4

// This will prevent sdwebimage load wrong url
guard let imgUrl = "Your image url.jpg" else { return }
imageView.sd_setImage(with: URL(string: imgUrl), placeholderImage: UIImage(named: "Your placeholder image.png"))


// Or you can match the url using this code, so the downloader won't catch the wrong url
if imgUrl == "Your image url" {
    imageView.sd_setImage(with: URL(string: imgUrl), placeholderImage: UIImage(named: "Your placeholder image.png"))
}


// This is will clean your UIImageView, and cancel download progress when cell is not visible (will reuse)
class YourCell: UITableViewCell {
    override prepareForReuse() {
        imageView.sd_cancelCurrentImageLoad()
        imageView.image = nil
    }
}

edited Oct 15 '22 at 16:31

miken32

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answered May 02 '17 at 07:10

Andrian Rahardja

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You better add this as comment - not an answer – moonvader May 02 '17 at 08:54
@moonvader hei is my Answer solved your problem? if yes please upvote, if not, please upvote too, because i already provide an answer. – Andrian Rahardja May 02 '17 at 18:48

score 1 · Answer 3 · answered Feb 12 '17 at 08:07

1

Firstly, you can use placeholder image of SDWebImage.

imageView.sd_setImage(with: URL(string: "http://www.domain.com/path/to/image.jpg"), placeholderImage: UIImage(named: "placeholder.png"))

Secondly, you can clean image when cell was reused.

class YourCell: UITableViewCell {
    override prepareForReuse() {
        // sample code
        imageView.image = nil
    }
}

answered Feb 12 '17 at 08:07

Lumialxk

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I tried to combine both methods that you suggest, but when I scroll fast - I still see that images are changing few times – moonvader Feb 12 '17 at 08:11
@moonvader I wonder how many times did you set the image for one cell. – Lumialxk Feb 12 '17 at 08:17
In cellForRowAt of my table I run function getImage(imageView: cell.ImageView, item_id: id) it takes imageview and id of item that it should find image for, after this it uses sd_setImage to load image to this imageview – moonvader Feb 12 '17 at 08:26

score 0 · Answer 4 · answered Feb 12 '17 at 15:33

0

Use

let cell = tableView.dequeueReusableCell(withIdentifier: "Cell", for: indexPath) as! NewsTableViewCell

Instead of

let cell = tableView.dequeueReusableCell(withIdentifier: "Cell") as! NewsTableViewCell

Hope it will solve Your problem. It is repeating because of reusability of Cell

answered Feb 12 '17 at 15:33

vp2698

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While your diagnosis is correct, this is not a solution to the problem. Cell reuse is a great optimisation technique so you should instead try to work with it, not around it. – Balázs Vincze May 03 '21 at 22:10

SDWebImage changing images while tableview scrolling

4 Answers4