iOS multi-image download

1 iOS multi-image download, download images in cell, Cache optimizer. 2 3 (App.icon is the image address)4 5 //Take the picture out of the memory cache first6UIImage *image =Self.images[app.icon];7     if(image) {//There are pictures in memory8Cell.imageView.image =image;9}Else{//no pictures in memoryTen         //Get library/caches folder OneNSString *cachespath =[Nssearchpathfordirectoriesindomains (Nscachesdirectory, Nsuserdomainmask, YES) firstobject]; A         //Get file name -NSString *filename =[App.icon lastpathcomponent]; -         //calculate the full path of a file theNSString *file =[Cachespath stringbyappendingpathcomponent:filename]; -         //loading the sandbox's file data -NSData *data =[NSData Datawithcontentsoffile:file]; -          +         if(data) {//Direct use of pictures in sandbox -UIImage *image =[UIImage Imagewithdata:data]; +Cell.imageView.image =image; A             //Save in Dictionary atSelf.images[app.icon] =image; -}Else{//Download Image -[Self.queue addoperationwithblock:^{ -                 //download pictures, multithreading -NSData *data =[NSData Datawithcontentsofurl:[nsurl URLWithString:app.icon]; -UIImage *image =[UIImage Imagewithdata:data]; in                  -[Nsthread Sleepfortimeinterval:1.0]; to                  +                 //back to main thread display picture -[[Nsoperationqueue Mainqueue] addoperationwithblock:^{ theCell.imageView.image =image; *                 }]; $                 Panax Notoginseng                 //Save in Dictionary -Self.images[app.icon] =image; the                 //writing picture file data into a sandbox + [Data writetofile:file atomically:yes]; A             }]; the}

iOS multi-image download