ios – 按其中一个键内的值对NSDictionaries数组进行排序

NSArray *sortedArray;
sortedArray = [unsortedArray sortedArrayUsingComparator:^NSComparisonResult(NSDictionary *first,NSDictionary *second) {
    // Calculate distances for each Dictionary from the device
    // ...
    return [firstDistance compare:secondDistance];
}];