collectionview

1.

https://github.com/search?l=Objective-C&q=UIGestureRecognizerStateEnded+performBatchUpdates&type=Code&utf8=%E2%9C%93

 

2.guid

 

+ (NSString*) stringWithUUID {
CFUUIDRef uuidObj = CFUUIDCreate(nil);//create a new UUID
//get the string representation of the UUID
NSString *uuidString = (NSString*)CFUUIDCreateString(nil, uuidObj);
CFRelease(uuidObj);
return [uuidString autorelease];
}

 

http://blog.csdn.net/tangaowen/article/details/7328088