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POMKMapView and setRegion:animated: not updating the map visuals
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  1. POMKMapView and setRegion:animated: not updating the map visuals
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    copied!<p>Greetings! I'm attempting to use <strong>MKMapView</strong> without any Apple code samples, though there are a few others out there of varying clarity. (I know, "Read the friendly manual." I've done that but it's not 100% clear, so please bear with me on this one.)</p> <p>Here's the situation. I have a <strong>MKMapView</strong> object, wherein I have added a set of about ten <strong>MKPinAnnotation</strong> objects. So far, so good. Everything is alloced/released sanely and there doesn't appear to be any complaints from Instruments.</p> <p>Upon initial display, I set up a <strong>MKCoordinateRegion</strong> object with the centerpoint at our first pin location, and a (arbitrary) span of 0.2 x 0.2. I then call:</p> <pre><code>[mapView setRegion:region animated:YES]; [mapView regionThatFits:region]; </code></pre> <p>Wow! That worked well. </p> <p>Meanwhile ... I also have a segmented control to allow for movement to each pin location. So as I tap through the list, the map animates to each new pin location with a new pair of calls to <strong>setRegion:animated:</strong> and <strong>regionThatFits:</strong> ... or at least that's the idea.</p> <p>While the map does "travel" to the new pin location, the map itself doesn't update underneath. Instead, I see my pin on a gray/blank-map background ... <em>until</em> I nudge the map in any direction, however slightly. Then the map shows through! (If I'm only moving within a short distance of the previous pin location, I'll usually see whatever part of the map was already loaded.)</p> <p>I suspect I'm doing something dumb here, but I haven't been able to figure out what, at least not from the MapKit docs. Perhaps I'm using the wrong calls? (Well, I do need to set the region at least once, yes? Moving that around doesn't seem to help though.) I have also tried using <strong>setCenterCoordinate:animated:</strong> - same problem.</p> <p>I'm assuming nothing at this point (no pun intended). Just trying to find my way.</p> <p>Clues welcome/appreciated!</p> <p>UPDATE: Calling <strong>setRegion:animated:</strong> and <strong>regionThatFits:</strong> the first time, followed by <strong>setCenterCoordinate:animated:</strong> while traversing the list, has no effect. Interesting finding though: If I change animated to NO in both cases, the map updates!!! Only when it's set to YES. (Wha happen?! Is animated: broken? That can't be ... ???)</p>
 

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