ios - 如何防止sortedArrayUsingSelector删除重复条目(ios)？

Question

如何使用以下方法对数组进行排序，并保留重复项？我想要的只是对distance数组进行排序，并按相同顺序对lineItems数组进行排序，以便我的订单项按距离进行排序。是否有捷径可寻？我已经尝试了很多不同的实现，但是没有运气。

lineItems = [[NSMutableArray alloc] initWithArray:(NSMutableArray *)[data objectForKey:@"line_items"]];
distanceArray = [[NSMutableArray alloc] initWithCapacity:[lineItems count]];
        for (int i = 0; i < [lineItems count]; i++) {
            CLLocation *spotLocation = [[CLLocation alloc] initWithLatitude:[[[lineItems objectAtIndex:i] objectForKey:@"latitude"] floatValue] longitude:[[[lineItems objectAtIndex:i] objectForKey:@"longitude"] floatValue]];
            CLLocationDistance distance = ([myLocation distanceFromLocation:spotLocation] / 1000) * 0.621371192;
            NSNumber *foo = [[NSNumber alloc] initWithDouble:distance];
            [distanceArray insertObject:foo atIndex:i];
        }

我的气泡排序实现:

for (int i=0;i<[distanceArray count]-1;i++){
            for(int j=1;j<[distanceArray count];j++){
                if ([[distanceArray objectAtIndex:i]doubleValue] >[[distanceArray objectAtIndex:j]doubleValue]){
                    NSNumber *temp_i = [[NSNumber alloc] initWithDouble:[[distanceArray objectAtIndex:i]doubleValue]];
                    NSNumber *temp_j = [[NSNumber alloc] initWithDouble:[[distanceArray objectAtIndex:j]doubleValue]];
                    [distanceArray removeObjectAtIndex:i];
                    [distanceArray removeObjectAtIndex:j];
                    [distanceArray insertObject:temp_j atIndex:i];
                    [distanceArray insertObject:temp_i atIndex:j];

                    NSDictionary *tempObj_i = [[NSDictionary alloc] initWithDictionary:[lineItems objectAtIndex:i]];
                    NSDictionary *tempObj_j = [[NSDictionary alloc] initWithDictionary:[lineItems objectAtIndex:j]];
                    [lineItems removeObjectAtIndex:i];
                    [lineItems removeObjectAtIndex:j];
                    [lineItems insertObject:tempObj_j atIndex:i];
                    [lineItems insertObject:tempObj_i atIndex:j];
                }
            }
        }

Answer 1

您的问题不是-sortedArrayUsingSelector:，而是NSDictionary的-allKeys方法。键在字典中是唯一的，因此-allKeys数组不会有任何重复项。

使用单独的NSArray实例存储排序结果，或使用inafziger的建议。