Question

I want to show alertview prior to querying the core data.

My core data will query hundred thousands record and it will take some time, but when I try to show the alertview, the alertview is displayed after the core data process is done?

What’s wrong with it? How can I show the alertview before querying?

Answer 1

I managed to solve this by:

dispatch_queue_t request_queue = dispatch_queue_create("com.appname.method", NULL);
dispatch_async(request_queue, ^{
Your long process here..
});

When need to update the GUI, use this:

dispatch_async(dispatch_get_main_queue(), ^{
});