使用SortDescriptor AND Predicate对NSMutableArray进行排序可能吗？

Question

我有一个类型为"餐厅"的阵列,其NSSet为"等级".评级有ID和值.

我想通过ID为01,从高到低的等级对餐厅的数组进行排序.

类似于以下内容,但如何在originalArray上一起使用谓词和排序描述符？

NSPredicate *predicate = [NSPredicate predicateWithFormat:@"Rating.rating_id=%d", ratingID];
NSSortDescriptor *descriptor = [NSSortDescriptor sortDescriptorWithKey:@"currentValue" ascending:YES];
NSArray *sorted = [[originalArray allObjects] sortedArrayUsingDescriptors:[NSArray arrayWithObject:descriptor]];

Answer 1

您可以使用NSComparator块对数组进行排序.

NSPredicate *predicate = [NSPredicate predicateWithFormat:@"rating_id = %d", ratingID];

NSArray *sorted = [array sortedArrayUsingComparator:^NSComparisonResult(id obj1, id obj2) {

    int value1 = [[[[obj1 ratings] filteredSetUsingPredicate:predicate] anyObject] currentValue];
    int value2 = [[[[obj2 ratings] filteredSetUsingPredicate:predicate] anyObject] currentValue];

    if ( value1 < value2 )
        return NSOrderedAscending;
    if ( value1 > value2 )
        return NSOrderedDescending;
    return NSOrderedSame;
}];