I have a asynchronous task like so:
dispatch_async(dispatch_get_main_queue(), ^{
myAsyncMethodsHere;
});
Is there a way to be notified when the background task is complete?
Or to call a method upon completion?
I've read through the documentation and have looked into dispatch_after, but it seems to be more designed to dispatch the method after a certain length of time.
Thanks for the help.
From the docs:
COMPLETION CALLBACKS
Completion callbacks can be accomplished via nested calls to the dispatch_async() function. It is important to remember to retain the destination queue before the first call to dispatch_async(), and to release that queue at the end of the completion callback to ensure the destination queue is not deallocated while the completion callback is pending. For example:
void
async_read(object_t obj,
void *where, size_t bytes,
dispatch_queue_t destination_queue,
void (^reply_block)(ssize_t r, int err))
{
// There are better ways of doing async I/O.
// This is just an example of nested blocks.
dispatch_retain(destination_queue);
dispatch_async(obj->queue, ^{
ssize_t r = read(obj->fd, where, bytes);
int err = errno;
dispatch_async(destination_queue, ^{
reply_block(r, err);
});
dispatch_release(destination_queue);
});
}
Source
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