How to unzip asynchronous way zip file in iOS?

Question

How do I unzip a file asynchronously? At the moment I am unzipping like this:

[SSZipArchive unzipFileAtPath:strZipFile toDestination:strDestPath];

But that blocks my main thread and the UI is unresponsive for longer than 10 seconds. The zip file is over 50MB, and I start the download in delegate on didFinishLaunching (to avoid long splash screen because it is not always necessary to have that file at the beginning.)

Answer 1

Run it in a background thread using GCD:

 dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
    [SSZipArchive unzipFileAtPath:strZipFile toDestination:strDestPath];
 });

You might want to tell your app you've finished unzipping by calling a method somewhere in the main thread:

 dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
    [SSZipArchive unzipFileAtPath:strZipFile toDestination:strDestPath];
    dispatch_async(dispatch_get_main_queue(), ^{
        [someClass finishedUnzippingFile:strDestPath];
    });
 });