SDWebImage Download image and store to cache for key

问题:

Hello I am using the SDWebImage framework in a project and I want to download and cache images, but I think my code is storing an image in the cache twice? Is there any way to store the image in the cache by a key only once? Here is my code.

         SDWebImageManager *manager = [SDWebImageManager sharedManager];          [manager downloadWithURL:[NSURL URLWithString:url] options:0 progress:^(NSUInteger receivedSize, long long expectedSize) {            } completed:^(UIImage *image, NSError *error, SDImageCacheType cacheType, BOOL finished) {              if(image){                 NSString *localKey = [NSString stringWithFormat:@"Item-%d", i];                 [[SDImageCache sharedImageCache] storeImage:image forKey:localKey];             }            }];   

Is there something that I missed? Looks like doing this in my allocations instrument is pilling up a lot of memory.

回答1:

I'm surprised nobody answered this question, but I've had a similar question and came across this, so I'll answer it for people viewing this going forward (assuming you've sorted this out yourself by now).

To directly answer your question, yes, you are caching the image twice.

Download calls to SDWebImageManager automatically cache images with keys based on the absoluteString of the image's url. If you want your own key, you can use the download call on SDWebImageDownloader which as far as I can tell does NOT cache by default. From there you can call the sharedImageCache as you're already doing and cache with whatever key you want.

That aside, it is strange you're seeing allocations piling up in any case as SDWebImage likes to cache to disk and not memory generally. Maybe something else is going on at the same time?

Hope this helps,

-Brandon

回答2:

In Swift use the code below to download an image and to store it in the cache:

//SDWebImageManager download image with High Priority       SDWebImageManager.sharedManager().downloadImageWithURL(NSURL(string: imageUrl), options: SDWebImageOptions.HighPriority, progress: { (receivedSize :Int, ExpectedSize :Int) in             SVProgressHUD.show()             }, completed: { (image :UIImage!, error:NSError!, cacheType :SDImageCacheType, finished :Bool,imageUrl: NSURL!) in                 if(finished) {                     SVProgressHUD.dismiss()                     if((image) != nil) {                         //image downloaded do your stuff                     }                 }         }) 

Swift 3 version:

SDWebImageManager.shared().downloadImage(with: NSURL(string: "...") as URL!, options: .continueInBackground, progress: {  (receivedSize :Int, ExpectedSize :Int) in  }, completed: {  (image : UIImage?, error : Error?, cacheType : SDImageCacheType, finished : Bool, url : URL?) in  }) 

Objective-C version:

[[SDWebImageDownloader sharedDownloader] downloadImageWithURL:[NSURL URLWithString:imageUrl] options:SDWebImageDownloaderUseNSURLCache progress:nil completed:^(UIImage *image, NSData *data, NSError *error, BOOL finished) {                      if (image && finished) {                         // Cache image to disk or memory                         [[SDImageCache sharedImageCache] storeImage:image forKey:CUSTOM_KEY toDisk:YES];                          }                 }];  

回答3:

Try APSmartStorage (https://github.com/Alterplay/APSmartStorage) instead of SDWebImage.

APSmartStorage gets data from network and automatically caches data on disk or in memory in a smart configurable way. Should be good enough for your task.

回答4:

SDWebImage caches the image both to disk as well as memory. Let's go through this:

1. You download the image from a new url.
2. It gets cached to memory and disk.
3. If you call the image in the same session, it is retrieved from the memory.
4. Let's say you re-run the app and then access the url, it will check the memory, where the image won't be there, then it will check the disk, and get it from there. If not, it will download it.
5. The image stays in disk for a week by the standard setting.

So, you don't need to worry about caching. SDWebImage takes care of it pretty damn well.

You can do custom implementation for caching as well as image refresh from the cache in case you want the settings as per your HTTP caching header as well.

You can find the complete details on their github page here.

回答5:

//CREATE A CUSTOME IMAGEVIEW AND PASS THE IMAGE URL BY ARRAY(INDEXPATH.ROW)

(void) loadImage:(NSString *)imageLink{      imageLink = [imageLink stringByReplacingOccurrencesOfString:@" " withString:@"%20"];      SDWebImageManager *manager = [SDWebImageManager sharedManager];      [manager loadImageWithURL:[NSURL URLWithString:imageLink] options:SDWebImageDelayPlaceholder progress:^(NSInteger receivedSize, NSInteger expectedSize, NSURL * _Nullable targetURL) {      } completed:^(UIImage * _Nullable image, NSData * _Nullable data, NSError * _Nullable error, SDImageCacheType cacheType, BOOL finished, NSURL * _Nullable imageURL) {          imageFrame.image = image;      }]; } 

回答6:

SDWebImageManager *manager = [SDWebImageManager sharedManager];  [manager downloadImageWithURL:ImageUrl options:0 progress:^(NSInteger receivedSize, NSInteger expectedSize)  {   } completed:^(UIImage *image, NSError *error, SDImageCacheType cacheType, BOOL finished, NSURL *imageURL) {      if(image){           NSLog(@"image=====%@",image);     } }]; 

文章来源: SDWebImage Download image and store to cache for key