Question

MY BAD I WAS ACTUALLY WRITING THIS CODE OUTSIDE IMPLMENTATION, WHAT A BIG NAIVE MISTAKE

I am learning GCD queues and creating blocks to run in background,

-(IBAction) refresh:(id) sender
{
    dispatch_queue_t downloadQueue = dispatch_queue_create("app data", NULL);
    dispatch_async(downloadQueue, ^{
        //. . . Call a method which download XML file from server . . .
        dispatch_async(dispatch_get_main_queue(), ^{
        //. . . Update UI with dowanloaded data . . .    
        });
    });
    dispatch_release(downloadQueue);
}

but this line of code is showing compile error

dispatch_queue_t downloadQueue = dispatch_queue_create("eiap data", NULL);

ERROR: initialiser element is not a compile-time constant

---

I can say that something is wrong with “app data” a const char which I am creating kind a on the fly, But I don’t know what is wrong with it?

Thanks

Answer 1

If I do this, it compiles:

dispatch_queue_t downloadQueue = dispatch_queue_create("app data", NULL);

but if I do this, I get exactly the error you mention:

static dispatch_queue_t downloadQueue = dispatch_queue_create("app data", NULL);

I think you’re declaring it static. Or you’re actually declaring it outside the method body, as a global variable.