Objective C: Downloading File With Progress Bar

Question

I am trying to put a progress bar that syncs during the download that is happening. My app now can download a file using with this codes...

    pdfData = [[NSData alloc] initWithContentsOfURL:[NSURL URLWithString:@"http://webaddress.com/pro/download/file.pdf"]];

    NSString *resourcePDFPath = [[NSString alloc] initWithString:[[[[NSBundle mainBundle]  resourcePath] stringByDeletingLastPathComponent] stringByAppendingPathComponent:@"Documents"]];

    pdfFilePath = [resourcePDFPath stringByAppendingPathComponent:@"myPDF.pdf"];

    [pdfData writeToFile:pdfFilePath atomically:YES];

During the process of this code the app stopped during download, is it normal? Now what I want is to put a progress bar during that stop time while downloading.

I tried looking into the codes I found online but I'm a bit confused, I think I need a step-by-step-well-explained reference.

score 60 · Accepted Answer · edited Mar 23 '14 at 07:37

Using AFNetworking,

here progress is the UIProgressview

#import <AFNetworking/AFNetworking.h>//add to the header of class

-(void)downloadShowingProgress
{
   progress.progress = 0.0;

    currentURL=@"http://www.selab.isti.cnr.it/ws-mate/example.pdf";


    NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:currentURL]];
    AFURLConnectionOperation *operation =   [[AFHTTPRequestOperation alloc] initWithRequest:request];

    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *filePath = [[paths objectAtIndex:0] stringByAppendingPathComponent:@"MY_FILENAME_WITH_EXTENTION.pdf"];
    operation.outputStream = [NSOutputStream outputStreamToFileAtPath:filePath append:NO];

    [operation setDownloadProgressBlock:^(NSUInteger bytesRead, NSUInteger totalBytesRead, NSUInteger totalBytesExpectedToRead) {
        progress.progress = (float)totalBytesRead / totalBytesExpectedToRead;

    }];

    [operation setCompletionBlock:^{
        NSLog(@"downloadComplete!");

    }];
    [operation start];

}

Using NSURLConnection

-(void)downloadWithNsurlconnection
{

    NSURL *url = [NSURL URLWithString:currentURL];
    NSURLRequest *theRequest = [NSURLRequest requestWithURL:url         cachePolicy:NSURLRequestReloadIgnoringLocalCacheData timeoutInterval:60];
    receivedData = [[NSMutableData alloc] initWithLength:0];
    NSURLConnection * connection = [[NSURLConnection alloc] initWithRequest:theRequest delegate:self     startImmediately:YES];


}


- (void) connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response {
    [UIApplication sharedApplication].networkActivityIndicatorVisible = YES;
    progress.hidden = NO;
    [receivedData setLength:0];
    expectedBytes = [response expectedContentLength];
}

- (void) connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
    [receivedData appendData:data];
    float progressive = (float)[receivedData length] / (float)expectedBytes;
    [progress setProgress:progressive];


}

- (void) connection:(NSURLConnection *)connection didFailWithError:(NSError *)error {
    [UIApplication sharedApplication].networkActivityIndicatorVisible = NO;

}

- (NSCachedURLResponse *) connection:(NSURLConnection *)connection willCacheResponse:    (NSCachedURLResponse *)cachedResponse {
    return nil;
}

- (void) connectionDidFinishLoading:(NSURLConnection *)connection {
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);

    NSString *documentsDirectory = [paths objectAtIndex:0];
    NSString *pdfPath = [documentsDirectory stringByAppendingPathComponent:[currentURL stringByAppendingString:@".mp3"]];
    NSLog(@"Succeeded! Received %d bytes of data",[receivedData length]);
    [UIApplication sharedApplication].networkActivityIndicatorVisible = NO;
    [receivedData writeToFile:pdfPath atomically:YES];
    progress.hidden = YES;
}

it says AFURLConnectionOperation is an undeclared identifier — SeongHo, May 09 '13 at 05:59
Edited the answer.Have to include #import in the class header — Lithu T.V, May 09 '13 at 06:01
I tried it but it is not found. What framework should I use? — SeongHo, May 09 '13 at 06:10
What is expectedBytes?? I'm sorry for asking so many questions. — SeongHo, May 09 '13 at 06:46
No, I mean data type. It ok now it's working thanks! I declared it as long. — SeongHo, May 09 '13 at 07:53
Honestly, I had no idea that NSURLResponse had an expectedContentLength property. Previously I was doing a HEAD request, then a GET request... It makes sense though, given how HTTP works... — Nate Symer, Jul 07 '13 at 16:44
and what if I am using a custom progress bar in response to the AFNetworking downloading. I have a block for progress in another view controller & that block is called from an object file but that progress is not working. could you help me out? — iYoung, Dec 08 '14 at 04:46
@RajatDeepSingh I think your question needs more information for it to be answered and I think it is better to raise it as a new question with details like the block for progress view and all — Lithu T.V, Dec 08 '14 at 06:38
With AFNetworking code,where I will get the content of file? I need to save that in Document Directory! — Developer, Jan 18 '17 at 10:15
I recommend the solution in this other thread, since `NSURLConnection` was deprecated back in iOS 9: https://stackoverflow.com/a/38063937/825644 — dinesharjani, Aug 06 '17 at 12:49
@dinesharjani Just in case your link to swift example not objective-c — Genevios, Jul 28 '19 at 11:10

score 1 · Answer 2 · answered May 09 '13 at 03:35

1

Use ASIHTTPRequest.h class and ASINetworkQueue.h for downloading the file.

and use this code for progress bar

    request = [ASIHTTPRequest requestWithURL:@"http://webaddress.com/pro/download/file.pdf];
    [request setDelegate:self];
    [request setDownloadProgressDelegate:progressView];
    [request setShowAccurateProgress:YES];
    request.shouldContinueWhenAppEntersBackground=YES;
    request.allowResumeForFileDownloads=YES;
    [request startAsynchronous];

this may help you

answered May 09 '13 at 03:35

Nithinbemitk

2,710
4
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should I put this on button click of the "Download"? – SeongHo May 09 '13 at 03:56
yes you want to place this code in button click function... – Nithinbemitk May 09 '13 at 05:35

score 0 · Answer 3 · answered May 09 '13 at 03:32

0

I'm afraid it's not normal, use asynchronous method to get the NSData.

answered May 09 '13 at 03:32

waterforest

154
1
8

score 0 · Answer 4 · answered May 09 '13 at 04:14

0

First of all you should be clear whether to make a synchronous call or asynchronous. For mobile apps or any other app asynchronous is preferred one.

Once you are clear use NSURLConnection class to fetch the data from the URL. Here is the good tutorial.

And for loading you can start progress while starting the request and stop it when you receive connection:didFailWithError: or connectionDidFinishLoading: delegate method.

answered May 09 '13 at 04:14

Inder Kumar Rathore

39,458
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How to download pdf file synchronously using NSURLConnection in swift @Inder Kumar Rathore – McDonal_11 Sep 11 '15 at 13:07

Objective C: Downloading File With Progress Bar

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