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.
Related
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.
This seems to me as a bug because I have changed images with:
someImage.image = [UIImage imageNamed:#"anotherImage.png"];
and I have never had a problem. so let me show you what I have:
I have placed an UIImageView:
note that imgObjetivos is conected to this UIImageView.
I have a method that get's called when clicking the following button:
and the method contains:
as you can see I just want to change the current image with:
so when I run the application in the simulator everything looks great:
and when I press the button the image changes successfully:
Now why is it that when I run the application on my iPad the image does not change!? when I press the button the image disappears instead of getting a new image like in the simulator. I just learned objective-c and I am starting to dislike it. What am I doing wrong?
EDIT
I found a solution I changed the name of the image and now it works:
but this makes no sense. Which names works and which ones do not? I also have make sure that I don't have two images with the same name and that is not the case. when I have a few letters after the '_' underscore it does not work. This is really strange. I am starting to dislike objective-c :(
I've had the same problem before. The problem is that the image that you're using to replace the previous image is corrupted or say is not in it's original format.
In my case, I downloaded images in the web which was .jpg format and renamed it as .png format which actually made it .png. so in short term, ipad does not support the functionality for converting image format by just renaming the extension. you have to have a proper converter or something.
I would go with removing the image file from the project, clean the project and add the file back.
I had to rename the image name to something else I don't understand why... I thought that the problem was because I previously deleted that image that contained the same name but that is not the case because I imported the image with a similar name to the solution and I had the same problem. for example the original name of the image was objetivosFoto_h.png and when I renamed to objetivosFoto_ho.png it still did not work but when I renamed to objetivosFoto_horizontal.png it worked.
I need an undefined amount of text and one or more pictures to be scrollable as one entity. I'm quite surprised that this doesn't seem to be provided by default, I thought I've seen that several times before... I tried to google, but all I find doesn't fit. The images won't be wider than the screen, but in between lines of text.
I need something that let's me do something like:
image
textA
textA goes on
__ screen ends here, content goes on
textA goes on
textA goes on
image
image
textB
textB goes on
image
textC
The content for the text would come out of a plist, but I THINK I can predict it will be REALLY static, so I could just set the Text in IB and create a view for every content -.-.
I've read about Web View, but as far as I got it, you'd need internet connection to make that work, and the app should work without any internet connection at all.
Any suggestions or experiences concerning that?
Thanks a lot!
There different way to get things done:
If you have static content and want a complicated layout and know how to do it in html you should go with UIWebview and a bundled html file and images and load it with something like:[webView loadRequest:[NSURLRequest requestWithURL:[NSURL fileURLWithPath:[[NSBundle mainBundle] pathForResource:#"MyStuff" ofType:#"html"]]]];
You can also do a layout with UILabels and UIImageviews and arrange all of this onto one UIScrollview
If it's more dynamic you should go with the latter, but you need to program sort of layout algorithms that handle different number/sizes of images, number/length of test paragraphs and so on.
One option, as you mention, is UIWebView.
It does not require a connection, since you can load a static HTML into it executing:
– loadHTMLString:baseURL:
By specifying a baseURL that "points" to your bundle, you can also include images as resources in your Xcode project and have them displayed (by using <img src=... /img in your HTML):
NSString* basePath = [[NSBundle mainBundle] bundlePath];
[_label loadHTMLString:text baseURL:[NSURL fileURLWithPath:basePath]];
You don't need an internet connection to make a web view work. Look at this method on UIWebView:
- (void)loadHTMLString:(NSString *)string baseURL:(NSURL *)baseURL
I am looking for a way to programmatically (in obj-c) generate a PDF file from a local html file. I am dynamically generating the html from user inputs, I need to create the PDF and send it to the user (via email). I am having difficulty with the PDF generation portion.
I have the code to create a PDF using CGPDFContextCreateWithURL but I am struggling with drawing the page using quartz.
I have searched extensively on SO as well as the internet to no avail.
Any help is much appreciated!
To generate a pdf from an HTML, you need to render the html into a web view, and take snapshots of the web view, and render them into an image context.
The tutorial might be helpful:
http://www.ioslearner.com/convert-html-uiwebview-pdf-iphone-ipad/
I've written a little piece of code that takes an NSAttributedString from DTCoreText, and renders it into a paged PDF file. You can find it on my GitHub Repository. It won't render images or complex html, but it should serve for most uses. Plus, if you're familiar with CoreText, you can extend my PDF frame setter to generate these items.
So what it does now: Give it an HTML string, and it will use DTCoreText to generate an NSAttributedString, then render that into a PDF. It hands back the location that it saved the PDF file in the app's Documents folder.
Why not use a WebService, send the HTML page to this and retrieve the PDF-file ?
That way you can use iTextSharp and C#, and you're done in about 2 minutes.
Plus (if you're evil) you can store and see all the data on your server.
I haven't tried this myself so i have nothing to offer concrete but I'd have to imagine there has to be an easy way to do this on iPhone due to the imaging model. I'd look deeper into the documentation.
As to pushing back with the client that is up to you but there are probably multiple reasons for wanting to keep everything local. Frankly I would not be pleased at all to here from somebody I hired that he couldn't manage this particular task. So think long and hard about this push back. Oh even if you do push back a webserver is a poor choice. I'd go back a step further and investgate why you need something in HTML in the first place.
I've never tried this so I have no idea if it'll work, but how about loading the HTML into a UIWebView, and then make the view draw itself into a PDF context? E.g.
UIWebView *webview = [[UIWebView alloc] initWithFrame:CGRectMake(...)];
[webview loadHTMLString:html baseURL:...];
Then:
- (void)webViewDidFinishLoad:(UIWebView *)webview {
CGPDFContextRef pdfContext = CGPDFContextCreateWithURL(...);
[webview.layer drawInContext:pdfContext];
...
}
I made it by following this SO: https://stackoverflow.com/a/13342906/448717
In order to maintain the same content's proportions I had to multiply the size of the WKWebView 1.25 times the printableRect's size set for the UIPrinterRenderer, as the screen points differs from the PostScript's... I guess.
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