在NSDictionary中讀取和寫入CGRect

//讀取
CGRect newFrame = [[change objectForKey:@"new"]CGRectValue];

//寫入

dictionary = [NSDictionary dictionaryWithObjectsAndKeys:
    [NSValue valueWithCGRect:CGRectMake(100,100,200,200)],
    @"Crocodile",
    nil];