Question

我有一个包含键@"Category"的对象数组（字典）。我必须通过从该键开始的特定键对其进行排序。例如，如果objects[@"Category"]: A, B ,C ,D ,E ,F ,G , H etc.中的值和用户选择“按C排序”，我需要通过[@"Category"]到的对象重新排序根数组：C，D，E，F，G，H ，A，B - 或 - C，A，B，D，E，F，G，H。

我希望很清楚我的目标是什么。我试过了：

//    sortedPosts2 = [self.objects sortedArrayUsingComparator:^(PFObject *object1, PFObject *object2)  {
//            return [object1[@"Category"] compare:object2[@"Category"] options:NSOrderedAscending];
//    }];


//    NSSortDescriptor *sort = [NSSortDescriptor sortDescriptorWithKey:category ascending:YES];
//    sortedPosts2 = [self.objects sortedArrayUsingDescriptors:[NSArray arrayWithObject:sort]];


    [self.tableView reloadSections:[NSIndexSet indexSetWithIndex:0] withRowAnimation:UITableViewRowAnimationTop];
}

Answer 1

我能想到的最简单的方法就是排序。然后，您可以手动调整数组比较值。这适用于Category中任何大小的字符串。您可能需要更改大于标志或升序/降序回报，我总是与升序/降序混淆......

NSArray *array;
NSString *userSelectedValue = @"C";
array = [array sortedArrayUsingComparator:^NSComparisonResult(id obj1, id obj2) {
    NSString *category1 = [[(NSDictionary*)obj1 objectForKey:@"Category"] lowercaseString];
    NSString *category2 = [[(NSDictionary*)obj2 objectForKey:@"Category"] lowercaseString];

    //Now check if either category's value is less than the user selected value
    NSComparisonResult result1 = [category1 compare:[userSelectedValue lowercaseString]];
    NSComparisonResult result2 = [category2 compare:[userSelectedValue lowercaseString]];

    if(result1 == result2)
    {
        return [category1 compare:category2];
    }
    else if(result1 > result2)
    {
        return NSOrderedDescending;
    }
    else
        return NSOrderedAscending;
}];

从特定值开始排序字典数组

1 个答案: