CGPoint itemSprite1position = CGPointMake(100, 200);
NSMutableArray * array = [[NSMutableArray alloc] initWithObjects:NSStringFromCGPoint(itemSprite1position),nil];
// 从数组中取值的过程是这样的：
CGPoint point = CGPointFromString([array objectAtIndex:0]);
NSLog(@"point is %@.", NSStringFromCGPoint(point));
可以用NSValue进行基础数据的保存，用这个方法更加清晰明确。
CGPoint itemSprite1position = CGPointMake(100, 200);
NSValue *originValue = [NSValue valueWithCGPoint:itemSprite1position];
NSMutableArray * array = [[NSMutableArray alloc] initWithObjects:originValue, nil];
// 从数组中取值的过程是这样的：
NSValue *currentValue = [array objectAtIndex:0];
CGPoint point = [currentValue CGPointValue];
NSLog(@"point is %@.", NSStringFromCGPoint(point));
