- NSArray存储模型,根据模型的某个属性匹配出具体位置
NSPredicate *predicate = [NSPredicate predicateWithFormat:@"chapIndex = %ld && pageCount = %ld",cp.chapIndex,cp.pageCount];
NSArray *cps = [self.chapContentArr filteredArrayUsingPredicate:predicate];
NSPredicate *predicate = [NSPredicate predicateWithFormat:@"chapIndex = %ld && pageCount = %ld",cp.chapIndex,cp.pageCount];
NSArray *cps = [self.chapContentArr filteredArrayUsingPredicate:predicate];