I'm displaying a list of icons downloaded from the web with text in a table view. The icons can be changed on server side and I need to replace them as soon as new icons are getting available. I try using the following code:
[imgView setImageWithURL:url placeholderImage:[UIImage imageNamed:#"table_avatar_icon"] options:SDWebImageCacheMemoryOnly];
And call [[SDImageCache sharedImageCache] clearMemory]; In my refresh callback, but it does not purge the contents of the cache. More to it, even if I close the application and open it again the image is still there.
I found only one way to clear the cache and it is by calling [[SDImageCache sharedImageCache] clearDisk];. Which only works after I close and reopen the app.
How can I force SDWebImage to not to use disk caching?
SDImageCache *imageCache = [SDImageCache sharedImageCache];
[imageCache clearMemory];
[imageCache clearDisk];
Don't forget to put these lines of code in your didReceiveMemoryWarning, too.
Located the source if an issue. It seems that I was deceived by the Singleton pattern used in SDImageCache. The cache for extension that is used over UIImageView is being controlled by SDWebImageManager which has an instance variable of SDImageCache. If you want to clear the cache for extension you have to call its imageCache's methods like clearDisk and clearMemory.
Only following code worked for me : Swift 5.0, Xcode 11, iOS 13, SDWebImage pod 5.0
SDWebImageManager.shared.imageCache.clear(with: .all) {
print("deleted all")
}
where you choose options like SDImageCacheType.disk, SDImageCacheType.memory, SDImageCacheType.disk
Also if you want to remove specific image from cache use following:
SDWebImageManager.shared.imageCache.removeImage(forKey: "url of image", cacheType: .all)
Except SDImageCache methods, I strongly advise you to check your image urls. In my situation I tried every method for imageCache and memory issue was still continue. Crashes were occur mainly on iPhone 4s because of hardware it couldn't handle it.
Main issue was url ampersand encoding!
In example, check out these urls: first url is using "&" and second one is not. Because of ampersand my JSON library can't read the width and width value get much higher then it should be. That is why I had a memory issue.
1) /select.php?imageid=101961221 "&" ;width=100 "&" ;isWatermarked=true
2) /select.phpimageid=101961221&width=100&isWatermarked=true
Also the latest versions of SDWebImage library has include UIImageView+WebCache.h class and it really nicely handle cache problems.
The icons can be changed on server side,
so you need to load with refresh cached every time.
if you're using latest SDWebImage framework (5.12.x)
you can call it like this,
[imgView sd_setImageWithURL:[NSURL URLWithString:urlStr] placeholderImage:[UIImage imageNamed:#"xxx" options:SDWebImageRefreshCached];
edit at 220112.
Related
I want to clear cache used by MHLazyTableImages for images when i changed images from server. but i am unable to find where it is storing that images. So Will you please guide me.
for clearing your MHLazyTableImages cache write following code line...
[[MHImageCache sharedInstance] flushMemory];
OR
instead of MHLazyTableImages, you use EGOImageView from EGOImageLoading
From my server I'm pulling down a url that is supposed to simply be a profile image. The relevant code for pulling down the image from the urls is this:
NSString *urlString = [NSString stringWithFormat:#"%#%#",kBaseURL,profile_image_url];
profilePic = [UIImage imageWithData:[NSData dataWithContentsOfURL:[NSURL URLWithString:urlString]]];
My url is in the format (note no file extension on the end since its dynamically rendered)
localhost:8000/people/1/profile_image
If I load the url in my browser the image displays; however the code above for pulling down the UIImage does not work. I've verified that the code does pull an image from a random site on the interwebs.
Any thoughts on why this is happening?
Does it work if you feed NSURL
http://localhost:8000/people/1/profile_image
I imagine that the http:// is important here (so that the NSURL knows whether it's pointing at a file or remote URL).
The reason you can't display it in a UIImageView is because the UIImageView doesn't know what format it's in (jpeg,png,etc.)
A good way for future coding is always use extensions. Don't take short cuts, they will always end up worse and you'll have to fix them over and over again.
First check for the following :
Permissions: change from read only to read and write.
I have tried many methods in my project to display pic from server and the most prominent issue i have found is that by default, your localhost folders are read only and you need to change permission as well.... Initially i thought read only wudnt matter if i am just loading the picture beacuse technically i am only reading the contents , right. But it did matter.
White Spaces
One more thing you coud check for is the name of your image containing white spaces, if they are then you need to remove white spaces from your image name while making URL request.
Try adding extensions if nothing works out
If eveythings fine , try to load the image with extensions which would obviously work.
Provide us with some initial coding as well
Let us know about your code snippets and console outputs which could help the community to reach the solution of the problem in a more prominent manner.
I'm currently using TTThumbsViewController in my project. I'm getting all the urls for TTPhotoVersionLarge and TTPhotoVersionThumbnail from the web so I can't tell that a url for the thumb images will work or not.
Currently the TTThumbsViewController will just display an empty image if the thumb url can't be loaded.
So I want to be notified if a thumb fails to load and do extra error handling when that happens like:
Try to load the url for TTPhotoVersionLarge
If that fails again display an error image (which is included in the bundle)
I have looked into the three20 code but can't find a proper place where I can implement this proper error handling.
The Three20 library is great, but I've found that it's often hard to change parts of their library such as this. For instance, TTThumbsViewController basically only allows you to set the dataSource and then takes care of the rest. If you want more control, perhaps look into code such as AQGridView: http://quatermain.tumblr.com/post/528737778/aqgridview-lives-for-my-ipad-dev-camp-hackathon
I've chosen to use that over Three20's equivalent because it gives you more control over what happens with your data.
Edit: In response to using TTThumbsViewController heavily, you may want to look at this method in TTTHumbsViewController.m:
- (NSString*)URLForPhoto:(id<TTPhoto>)photo {
if ([photo respondsToSelector:#selector(URLValueWithName:)]) {
return [photo URLValueWithName:#"TTPhotoViewController"];
} else {
return nil;
}
}
It looks like you should be able to specify a different value there so long as you can find something to add to the if statement determining if the initial loading failed from the dataSource.
I am learning iPhone development, and have built a simple app that has an image that changes to another image when you tap it.
If i build it to the simulator, it works fine, but if i build it to the device the images dont appear. i feel like they aren't being copied across. I have checked they have been named correctly and i have made sure i imported them to 'resources'
I dont think it is a problem with the code because i added a thing to also make text appear when the image is tapped, and this works, so a button is still there doing something, it just doesn't have an image on it.
-(IBAction)changeImage:(id)sender {
[fortuneCookieButton setImage:[UIImage imageNamed:#"Image2.jpg"] forState:UIControlStateNormal];
label.hidden = NO;
}
-(IBAction)restoreImage:(id)sender {
[fortuneCookieButton setImage:[UIImage imageNamed:#"Image1.jpg"] forState:UIControlStateNormal];
label.hidden = YES;
}
Does the case (upper/lower) of all your file names match exactly for all letters? Source code & project & Mac?
just to share with you, I had this same problem and I found out the solution: I was using lower case in the file name and upper case in code. The thing is on Simulator there was no problem because Mac file system is case-insensitive but in the iPad it didn't work because iOS file system is case sensitive. ;-)
I had this problem. Bizarrely the image had been working in the past, then just stopped appearing on the device one day.
It was a PNG.
I opened it in GIMP and saved it again. Then it went back to working again. No idea why.
Crazy.
Is it the case with only PNG images or also for JPG & other format you're having same issue. If it's only for PNG image, then it might be possible they're not being compressed. Try the following way.
Select your project target & go into its info. Here go into the build tab. In the configuration select "All Configurations" from Configuration section. Now, write "COMPRESS_PNG_FILES' in the search bar. And see the status of the check-box. IF it's unchecked, then make it checked & it will work. But if it's already checked, then there should be other reason in your project.
In the later case, I would request you to create a new dummy project & check by adding 2-3 images whether it's coming or not.
Clear caches delete the previous build and try again.
I also had same problem, and it was caused by a different reason: my project has image files with the same name! Since my app has many images, I inadvertently included images with the same name. Simulator is more tolerant and show the images just fine; however, when built on device, neither of the images of the same name were copied to the build directory. Obviously xcode is more picky for device: since all images go to the same directory, the file names must be different. When there are files with the same name, xcode refuses to copy any of them since it doesn't know which one to pick.
I have the same problem. In my case, the issues is to do with the UILabel above the UIImageView that shows the image. When I change the type of UILabel to AttributedText (In Property Inspector), my real devices cannot load the image. When I change it back to Plain, it works now. I use XCode 6.2.
on top of all suggestions - it wasn't work for me until I restarted the device
I have create an application on iphone using objective-c.In this application i am just displaying different players images stored in one folder, which will be run perfectly on simulator. But when I deploy it on iphone it is not showing the images of the player.
for that the code is:
UIImageView *imageplayer = [[UIImageView alloc]initWithFrame: CGRectMake(imgx, imgy+45,135,150)];
imageplayer.image = [UIImage imageNamed:playerpng];
if(imageplayer.image == nil)
[imageplayer setImage:[UIImage imageNamed:playerjpg]];
if(imageplayer.image == nil)
[imageplayer setImage:[UIImage imageNamed:#"noimage.png"]];
[self.view addSubView:imageplayer];
Plz solve this query.
Thanks in advance
Sometimes xCode doesent update correctly the bundle, try cleaning and building again.
I am currently experiencing this problem as well. I was able to correct it after a bit of debugging and reviewing the build file.
When I do an ls -l, I noticed that some of my png files have a # symbol beside the permissions. When I followed that up with a ls -l#, it showed that the files with an '#' had an attribute set 'com.apple.quarantine'. This attribute is given to a file (often from a zip, jar, or other executable) that is downloaded from the net. You can get rid of this attribute by performing:
xattr -d com.apple.quarantine *.png
Then, select the images in XCode, and check that the checkbox under the target is checked. In my case, it was not, so the images weren't being included in the bundle.
I had the same problem, solved by using all lowercase for the file name in code - image.jpg, but it does not seem to make any difference what case the actual file name is, e.g. Image.jpg
check name of image file. It must be "noimage.png"
not Noimage.png or noimage.PNG
Just to clarify, does the "noimage.png" display, or is the program loading a player image but failing to display it? Or is nothing loading.
These should easily be determined in debug mode.
A few additional things to check...
1) Just for testing, start out with PNG versions of the player files. This is the primary format on the iPhone and might eliminate a file format issue or other anomaly that the simulator is not sensitive to.
2) With regard to fixing in an image editor, specifically make sure that the image is set to a DPI of 72 pixels/inch. The iPhone and particularly Interface Builder are very sensitive to this being correct and will sometimes not display or will display a very blurred version of the image if incorrect.
3) Make sure the image(s) haven't been added multiple times (from different directories and/or to different group folders). We encountered a situation where we had inadvertently imported the same images at two different layers within the project hierarchy and this can cause unexpected behavior within the iPhone (selecting randomly or failing to select).
4) Make sure the Get Info -> Targets has your particular target checked. The simulator may still see the image but it will not get deployed to the iPhone.
5) Make sure you can view the image within XCode and that it looks correct.
Barney
This happens to me sometimes. I once spent half a night trying to figure out what was wrong. In this end, this is what worked: open the image with an image editor and save it again. That's all. I'm using the free Acorn image editor to do this. Haven't tried it with Photoshop. (After all, it seems that Photoshop might be responsible for introducing the error in the first place, although that's far from sure.)
I don't know what causes the problem. I usually get it when I use png files that have been sent to me. Could be a simple file permissions problem, or some more subtle problem with the image format. I would be very interested in hearing the opinion of better-informed people.
In any case, if all else fails just try this: open the image with Acorn, save over the original file. Works for me.
Make sure the image files are added to your XCode project.
After some investigation, Michael's comment seems to have a solved it for me. I had all lower case as the file name but was following variable convention and had the png file with an upper case for the second part of the file name. Here my file was putback.png but was referenced in my code as putBack.png
UIImage *putBackImage = [UIImage imageNamed:#"putBack.png"]; //wrong
UIImage *putBackImage = [UIImage imageNamed:#"putback.png"]; //correct
Select correct target while adding image files to your project. Following are steps to make it further clear
Select Add Files to "YourProjectName"
In opening window there is an "Add to targets" option at bottom that shows all available targets
Check target or multiple targets in which you want to add images
Press "Add" button and you are ready to go