Progress bar while downloading

Question

I have an app with in-app downloading. I successfully download mp3 files in this way:

NSData *data1 = [NSData dataWithContentsOfURL:[NSURL URLWithString:@"http://.../somefile.mp3"]];
[data1 writeToFile:filePath atomically:YES];

But there is really big pause while this code is executing. How can I work out the progress of the download and display it with a progress bar?

Take a look at https://github.com/jdg/MBProgressHUD to show the progress. — Tim Büthe, Mar 22 '12 at 11:22

score 4 · Accepted Answer · answered Mar 22 '12 at 10:54

The problem is that dataWithContentsOfURL: is a blocking call. This means that it will block the thread that it is running on.

You've got a couple of options to fix this, and the better one is probably to use an NSURLConnection.

With an NSURLConnection you can perform the download request asynchronously, which will prevent it from blocking the main thread.

You must use the NSURLConnectionDelegate methods to be informed of the progress of the download, save its data, and to be informed of success or failure.

Please read the documentation for the NSURL Loading System.

An alternative to using NSURLConnection is to wrap your current code with some calls to GCD using dispatch queues. This will prevent the call from blocking your UI, but it will not allow you to determine the progress - for that you will still need to use NSURLConnection.

Yeah, i know about blocking. Thnx for NSURLConnection =) – Eugene Trapeznikov Mar 22 '12 at 11:03 — Eugene Trapeznikov, Mar 22 '12 at 11:03

score 1 · Answer 2 · answered Mar 22 '12 at 10:45

1

You should really have a look at the ASIHTTPRequest and especially this section

It provides callbacks for tracking your downloads, async and sync connections, queues, caching and lots of good stuff.

answered Mar 22 '12 at 10:45

Alladinian

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Note the warning on top of the page: _Please note that I am no longer working on this library - you may want to consider using something else for new projects. :)_ – Tim Büthe Mar 22 '12 at 10:59
1

@TimBüthe Yes I just saw it! :P But I still think that is a great library and if one only cares for some of the classes it's relatively easy to maintain it by himself. But, hey, that's my opinion I guess :) – Alladinian Mar 22 '12 at 11:08

Progress bar while downloading

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