如何监控iPhone SDK中的pdf下载过程

在我的应用程序，我需要从url.i下载pdf文件知道如何从url下载PDF文件，并存储在本地文件目录。但我需要显示下载过程，我想知道下载是否完成。请任何机构给理念..

在这里我的代码：

NSData *pdfData = [[NSData alloc] initWithContentsOfURL:[NSURL URLWithString:@"http://www.msy.com.au/Parts/PARTS.pdf"]]; //Store the Data locally as PDF File NSString *resourceDocPath = [[NSString alloc] initWithString:[[[[NSBundle mainBundle] resourcePath] stringByDeletingLastPathComponent] stringByAppendingPathComponent:@"Documents"]]; NSString *filePath = [resourceDocPath stringByAppendingPathComponent:@"myPDF.pdf"]; [pdfData writeToFile:filePath atomically:YES]; 

Answer 1

使用ASIHTTPRequest下载文件。 下面的代码我已经使用ASIHTTPRequest

 float currentProgress; UILabel *dwnLbl; UIProgressView * myProgressIndicator; UIProgressView *progressBar; @property (nonatomic, retain) ASIHTTPRequest *rqstForAudio; -(void)viewDidLoad{ self.av=[[UIAlertView alloc] initWithTitle:@"Downloading.." message:nil delegate:self cancelButtonTitle:nil otherButtonTitles:nil]; [self.actV setFrame:CGRectMake(125, 60, 37, 37)]; dwnLbl = [[UILabel alloc] initWithFrame:CGRectMake(45, 30, 200, 37)]; dwnLbl.textAlignment = UITextAlignmentCenter; dwnLbl.font = [UIFont boldSystemFontOfSize:20]; dwnLbl.backgroundColor = [UIColor clearColor]; dwnLbl.textColor = [UIColor whiteColor]; progressBar = [[UIProgressView alloc] initWithProgressViewStyle:UIProgressViewStyleBar]; [progressBar setFrame:CGRectMake(45, 65, 200, 20)]; progressBar.progress = 0; [self.av addSubview:dwnLbl]; [self.av addSubview:progressBar]; } -(void)downLoadBook{ NSString *strAudioURL=@"http://www.msy.com.au/Parts/PARTS.pdf" // check first locally exists or not NSString *strPathToAudioCache=[NSString stringWithFormat:@"%@/%@", [(NSArray*)NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0], AudioFolder]; NSDictionary *dOfAudios=[NSDictionary dictionaryWithContentsOfFile:strPathToAudioCache]; if([dOfAudios valueForKey:strAudioURL]) { } else { self.av.title = @"Downloading.."; [self.av show]; NSString *pdf = @"bookTitle.pdf"; NSURL *audioURL = [NSURL URLWithString:strAudioURL]; NSString *strPathToDownload=[NSString stringWithFormat:@"%@/%@",[(NSArray*)NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0],pdf]; [self.rqstForAudio setDownloadProgressDelegate:myProgressIndicator]; if(!self.rqstForAudio || [self.rqstForAudio isFinished]) { self.rqstForAudio=[ASIHTTPRequest requestWithURL:audioURL]; [self.rqstForAudio setDelegate:self]; [self.rqstForAudio setDownloadProgressDelegate:self]; [self.rqstForAudio setAllowResumeForFileDownloads:YES]; [self.rqstForAudio setCachePolicy:ASIUseDefaultCachePolicy]; [self.rqstForAudio setCacheStoragePolicy:ASICachePermanentlyCacheStoragePolicy]; [self.rqstForAudio setDidFailSelector:@selector(failedToLoad:)]; [self.rqstForAudio setDidFinishSelector:@selector(finishedLoading:)]; [self.rqstForAudio setDownloadCache:[ASIDownloadCache sharedCache]]; [self.rqstForAudio setDownloadDestinationPath:strPathToDownload]; [self.rqstForAudio startAsynchronous]; } } } - (void)failedToLoad:(ASIHTTPRequest*)request { [self.av dismissWithClickedButtonIndex:0 animated:YES]; NSLog(@"failed to download"); UIAlertView *av = [[UIAlertView alloc] initWithTitle:@"MESSAGE" message:@"Failed to Download" delegate:self cancelButtonTitle:RETRY otherButtonTitles:nil, nil]; av.delegate = self; [av show]; } - (void)finishedLoading:(ASIHTTPRequest*)request { NSLog(@"finished loading"); NSString *strPathToAudioCache=[NSString stringWithFormat:@"%@", [(NSArray*)NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0]]; NSMutableDictionary *dOfAudios=[NSMutableDictionary dictionaryWithContentsOfFile:strPathToAudioCache]; if([dOfAudios allKeys].count>0) { [dOfAudios setValue:[request downloadDestinationPath] forKey:[[request url] description]]; } else { dOfAudios=[NSMutableDictionary dictionary]; [dOfAudios setValue:[request downloadDestinationPath] forKey:[[request url] description]]; } [self.av dismissWithClickedButtonIndex:0 animated:YES]; [dOfAudios writeToFile:strPathToAudioCache atomically:YES]; } - (void)request:(ASIHTTPRequest *)request didReceiveBytes:(long long)bytes{ [self setProgress:[myProgressIndicator progress]]; } - (void)setProgress:(float)progress { currentProgress = progress; if (!progress == 0.0) { } if(currentProgress*100 == 100.00){ self.av.title = @"Finishing.."; } progressBar.progress = currentProgress; dwnLbl.text = [NSString stringWithFormat:@"%.2f%%",currentProgress*100]; } 

编辑

你可以使用NSURLSession方法来实现NSURLSession这样的场景

Answer 2

我强烈build议看看ASIHTTPRequest ，以便下载文件。

通过您可以使用下载进度的function数量。