IOS File Download (afnetwork three-party framework with Progressview) five

1. Create a request

-(void) download2{        nsstring *urlstring = @ "Http:192.168.0.179:8080/myweb/download.do";    URLString = [URLString stringbyaddingpercentescapesusingencoding:nsutf8stringencoding];      NSLog (@ "Hello");    Nsurl *url = [Nsurl urlwithstring:urlstring];    Nsurlrequest *request = [Nsurlrequest requestwithurl:url];    [[Self.session downloadtaskwithrequest:request] resume];    }

One last sentence

[[Self.session downloadtaskwithrequest:request] resume];

The session, this article uses lazy loading

2. Session lazy loading, and add agent, listen to file download situation

Lazy Loading-(nsurlsession *) session{    if (_session = = nil)    {        nsurlsessionconfiguration *config = [ Nsurlsessionconfiguration Defaultsessionconfiguration];                _session = [nsurlsession sessionwithconfiguration:config delegate:self delegatequeue:nil];            }    return _session;}

3. Progress update and label download percent complete update (note that it must be updated on the main thread, otherwise it cannot be displayed)

/* Sent periodically to notify the delegate of download progress. *//**[""] * @brief update progress bar, use this agent [""] *[""] * @param session session[""] * @param downloadtask download task [""] * @param byteswritten Current Write Bytes[""] * @param totalbyteswritten Current total write bytes[""] * @param totalbytesexpectedtowrite expected write total bytes[""] *[""] * @return < #return value description#>[""] */-(void) Urlsession: (Nsurlsession *) session Downloadtask: ( Nsurlsessiondownloadtask *) Downloadtask      didwritedata: (int64_t) Byteswritten Totalbyteswritten: (int64_t) Totalbyteswrittentotalbytesexpectedtowrite: (int64_t) totalbytesexpectedtowrite{    Float progress = (float) Totalbyteswritten/totalbytesexpectedtowrite;    NSLog (@ "%f", progress);    Main thread Update UI   Dispatch_async (Dispatch_get_main_queue (), ^ (void) {        self.progresslabel.text=[nsstring stringwithformat:@ "%%%.0f", progress*100];             [Self.progressview setprogress:progress animated:yes];    }          

4. The download is complete and the downloaded data is written to the specified cache path.

/** [""] * @briefThe delegate should copy or move the file at the given location to a new location as it would be Removed when the delegate message returns. [""] *[""] * @param session session description[""] * @param downloadtask downloadtask Download task [""] * @param location Download document position (temporary) [ ""] *[""] * @return [""] */-(void) Urlsession: (Nsurlsession *) session Downloadtask: (Nsurlsessiondownloadtask *) Downloadtaskdidfinishdownloadingtourl: (Nsurl *) location{nsstring *cachedir = Nssearchpathfordirectoriesindomains (        Nscachesdirectory, Nsuserdomainmask, YES) [0]; NSString *retstr = [DownloadTask.response.suggestedFilename stringbyreplacingpercentescapesusingencoding:    Nsutf8stringencoding];        NSLog (@ "%@ \ n", retstr);    NSString *path = [Cachedir stringbyappendingpathcomponent:retstr];    NSLog (@ "%@", Path);    Nsurl *url2=location;     nslog (@ "%@", location);    NSData *mydata=[nsdata Datawithcontentsofurl:location]; [MyData Writetofile:path atomically:yes];}

IOS File Download (afnetwork three-party framework with Progressview) five