iOS use cached image with SDWebImage properly

Question

I am using SDWebImage to get pictures.

let's say I have two view controllers A and B. B is the next view of A. they need to show the same image:

[iconIamgeView setImageWithURL:[NSURL URLWithString:@"http://www.example.com/icon.jpg"];

I thought SDWebImage would cache http://www.example.com/icon.jpg after this code in A, so B was going to use the cache. Thus there should not be a detectable latency when I used this code to show the same image in B. However, it seems that I was wrong. there was an obvious latency when I wanted to show this image in B.

How can I use the cache properly? thanks!

do u have #import added? and the settings properly set? it should have worked — Firdous, Apr 24 '13 at 10:15
yes, I have imported the header. I can use SDWebImage successfully without the cache part. what do you mean "the settings properly set"? thanks! — Brian, Apr 24 '13 at 10:45
yeah, as I can use it, I think I've installed it successfully. So, in normal case, SDWebImage should cache the image when using `setImageWithURL`, right? — Brian, Apr 24 '13 at 11:38

score 0 · Accepted Answer · answered Apr 24 '13 at 15:12

I am sorry that the problem I mentioned in the question was not the real problem.

[iconIamgeView setImageWithURL:[NSURL URLWithString:@"http://www.example.com/icon.jpg"];

this code does the cache work well.

the real problem is my code of setting image was not on the main thread, so I could not show the image immediately. I used dispatch_async to solve the problem:

dispatch_async(dispatch_get_main_queue(), ^{
    [iconIamgeView setImageWithURL:[NSURLURLWithString:@"http://www.example.com/icon.jpg"];
});

hope this answer may help someone who faces the same issue.

score 0 · Answer 2 · edited Mar 28 '14 at 22:00

0

NSURL *imageURL = [NSURL URLWithString:[linkImageArray objectAtIndex:index]];
UIImage *placeholderImage = [UIImage imageNamed : [linkImageArray objectAtIndex: index]];

[imageView setImageWithURL:imageURL
          placeholderImage:placeholderImage
                   options:SDWebImageRefreshCached
                 completed:^(UIImage *image, NSError *error, SDImageCacheType cacheType)
                   {
                       NSLog(@"image loaded");
                   }];

edited Mar 28 '14 at 22:00

atticus

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answered Feb 28 '14 at 06:15

user2632844

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Please fix the post. Currently, it is a dumped mess. – László Papp Feb 28 '14 at 06:32

iOS use cached image with SDWebImage properly

2 Answers2