?????????reuseIdentifier????????????table view???ò???????μ?cell????????????????????????????app???????????????

??????iOS6??????UICollectionView??cells?????views??????????header??footer views?????reuseIdentifiers??

??????????reuseIdentifiers??????????table view?????????μ?cell???data source object??????????????
 
static NSString *CellIdentifier = @"Cell";
 UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];

???????????????Щ????????cell???????????????????????????????nib????class?????μ?cell???????п??????cell??????????????class????nib????????????????nil??

????3.??????views????????

????????????????Views??????????????opaque?????YES??

??????????????????????????????Щviews???????????????IB??????????????趨??

????Apple???????????????????????????????

????(opaque)??????????????????????δ??????view?????????????YES?? ???????????view???????????????????????????Щ????????????????????????NO????????????????????????????View????????YES??

???????????????????У???????????????????????????????view???scroll view????????????????????????????????????????????????????????app???????

????????????????????DebugColor Blended Layers???????????Щview??б??????opaque?????????????opaque??????opaque!

????4. ???????????XIB

????iOS5?м????Storyboards(???)??????????XIB?????XIB???Щ??????????????á????????app??????iOS5?????豸?????????????????????????view???????????????????

??????????ò?XIB?????????????????????????Controller?????????????XIB????????????View Controller??view??ν????????????XIB?????

????????????????????????XIB????????????????????????????????κ????????????????????????view??????????????????????????Storyboards?????????????storyboard????????????????view controller.

??????????XIB?????????????chache???????????OS X????????????????????Apple?????????е???????

???????????????????????????????????nib???nib????????????????????д????檔??OS X?У????????????????????named cache??????????????????iOS?У?????????????named caches?????????????????????NSImage ??UIImage ??`imageNamed:`????????????????

???????????????????????????storyboards?У?????????????κ??????????????????????????????????д?????!

????????????????storyboards???????????????? Matthijs Hollemans??Beginning Storyboards in iOS 5 Part 1 ?? Part 2

????5. ????????????

????????????????е????????UIKit??????????????й????????????????????????????????????????????ɡ?

????????????????????????????????block???????????app?????????????????????App Store????????????? :]

?????????譚????????????????app?????Щ??浽??д???????I/O??????????洢???????硣

????????????`NSURLConnection`?????????????:

????+ (void)sendAsynchronousRequest:(NSURLRequest *)request queue:(NSOperationQueue *)queue completionHandler:(void (^)(NSURLResponse*?? NSData*?? NSError*))handler

????????????? AFNetworking??????????????????Щ??????

???????????????????????????????????????(?????????е???????洢??д)???? Grand Central Dispatch?????? NSOperation ?? NSOperationQueues.

????????????????GCD?????
 
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT?? 0)?? ^{
    // switch to a background thread and perform your expensive operation
 
    dispatch_async(dispatch_get_main_queue()?? ^{
        // switch back to the main thread to update your UI
 
    });
});