iOS Development Swift version asynchronously loads network pictures (with cache and default Picture)

<span id="Label3"></p>The swift version of iOS development asynchronously loads network pictures<p><p><span style="font-size: 16px;">With the Sdwebimage asynchronous load network picture function is similar, just the code is relatively simple, the function is not perfect and powerful sd, support default add picture, support local Cache.</span><br></p></p> <p><p><span style="font-size: 16px;">the core code for loading images asynchronously is as Follows:</span><br></p></p> <pre class="brush:shell;toolbar: true; auto-links: false;"> func setzyhwebimage (url:nsstring?, defaultimage:nsstring?, iscache:bool) {         var ZYHImage:UIImage?         if url == nil {             return        }        // Set default picture         if defaultImage != nil {             self.image=uiimage (named: defaultImage!)         }        //whether to cache processing         if isCache {         //cache Management class             var data: Nsdata?=zyhwebimagechchecenter.readcachEfromurl (url!)             if data != nil {                 zyhimage= UIImage (data: data!)                 self.image= zyhimage            }else{             //getting Asynchronous Threads                 var dispath=dispatch_get_global_queue (DISPATCH_QUEUE_PRIORITY_HIGH,  0)                  Dispatch_async (dispath, {  ()  -> Void in                     var url:nsurl&nbsP;= nsurl (string: url!)!                      var data:nsdata?=nsdata (contentsofurl: url)                      if data != nil  {                         zyhimage=uiimage (data: data!)                          //write Cache                           Zyhwebimagechchecenter.writecachetourl (url!, data: data!)                 &nbSp;       //refresh ui          in main thread                dispatch_async ( Dispatch_get_main_queue (), {  ()  -> Void in                              //refresh Main ui                             self.image=zyhimage                          })                      }                                      })             }         }else{             var dispath=dispatch_get_global_queue (dispatch_queue_priority_high, 0)              dispatch_async (dispath, {  ()  ->  void in                 Var url:nsurl = nsurl (string: url!)!                 var data: Nsdata?=nsdata (contentsofurl: url)                  if data != nil {                    zyhimage =uiimage (data: data!)                      //write Cache                      dispatch_async (dispatch_get_main_queue (), {  ()  -> Void  in                         //refresh Main ui                         self.image=ZYHImage                      })                 }                             })          }    }    }</pre> <p><p> <span style="font-size:16px;"> Cache processing Here is the way to write files, through the file name to manage the cache, the framework is not perfect, followed by the addition of cache cleanup Functions. The core code for the cache is as follows: </span> <br> </p></p> <pre class="brush:shell;toolbar: true; auto-links: false;">Class func readcachefromurl (url:nsstring)->nsdata? {        var data:nsdata?         var path:nsstring=zyhwebimagechchecenter.getfullcachepathfromurl (url)          if nsfilemanager.defaultmanager (). Fileexistsatpath (path)  {             data=nsdata.datawithcontentsofmappedfile (path)  as?  NSData        }         return data    }        class func  Writecachetourl (url:nsstring, data:nsdata) {        var path: Nsstring=zyhwebimagechchecenter.getfullcachepathfromurl (url)        println ( Data.writetofile (path, atomically: true))     }    //set Cache Path     class func  Getfullcachepathfromurl (url:nsstring)->nsstring{        var  Chchepath=nshomedirectory (). stringbyappendingstring ("/library/caches/mycache")          var filemanager:nsfilemanager=nsfilemanager.defaultmanager ()          filemanager.fileexistsatpath (chchepath)          if ! (filemanager.fileexistsatpath (chchepath))  {             filemanager.createdirectoryatpath (chchepath, withintermediatedirectories: true,  Attributes: nil, error: nil)         }         //for string Processing         var newurl: nsstring     &Nbsp;  newurl=zyhwebimagechchecenter.stringtozyhstring (url)          chchepath=chchepath.stringbyappendingformat ("/%@",  newurl)          return chchePath    }         class func stringtozyhstring (str:nsstring)->nsstring{         var newstr:nsmutablestring=nsmutablestring ()          for var i:nsinteger=0; i < str.length; i++ {             var c:unichar=str.characteratindex (i)              if  (c>=48&&c<=57) | | (c>=65&&c<=90) | | (c>=97&&c<=122) {                newstR.appendformat ("%c",  c)             }         }        return  Newstr.copy ()  as nsstring            }</pre> <p><p><span style="font-size: 16px;"></span><span style="font-size: 16px;">Frame of GitHub address, welcome correction and Extension: Https://github.com/ZYHshao/swift-ZYHWebImage</span></p></p> <p><p><span style="font-size: 16px;">Because of the different versions of xcode, The Swift language syntax varies from time to time, and this version is available in 6.1, and a few changes are required in later Versions.</span><br></p></p> <p><p><span style="font-size: 16px;"></span><br></p></p> <p><p><br></p></p><p><p>iOS Development Swift version asynchronously loads network pictures (with cache and default Picture)</p></p></span>