如何按距離的升序對NSmutable數組進行排序？

Question

我有一個nsmutable朋友列表list.each有他們的lat和longs.I想要按照他們與autor的距離的上升速率對該數組進行排序。我發現了與autor的朋友的距離值，現在我想要排序在他們的距離上升的數組。這就是我這樣做的方式，`

for(int i=0;i<[searchfriendarray count];i++)
        {
            NSDictionary *payload =[searchfriendarray objectAtIndex:i];
            NSLog(@"%@",payload);
             NSString *memberid = [payload objectForKey:@"userID"];
             CLLocation *locationofauthor;
            CLLocation *locationoffriends;
           if([memberid isEqualToString:uidstr])
            {

               NSString *latofauthor = [payload objectForKey:@"latitude"]; 
               NSString *longofauthor=[payload objectForKey:@"longitude"];
              double latofauthordouble = [latofauthor doubleValue];
             double longofauthordouble=[longofauthor doubleValue];;
            locationofauthor = [[CLLocation alloc] initWithLatitude:latofauthordouble  longitude:longofauthordouble];

            }
            else
            {
             NSString *latoffriends = [payload objectForKey:@"latitude"]; 
             NSString *longoffriends=[payload objectForKey:@"longitude"];
               double latoffriendsdouble = [latoffriends doubleValue];
                double longoffriendsdouble=[longoffriends doubleValue];;
               locationoffriends = [[CLLocation alloc] initWithLatitude:latoffriendsdouble  longitude:longoffriendsdouble];

              }
             CLLocationDistance distance = [locationofauthor distanceFromLocation:locationoffriends];

}

“任何身體都可以幫助我按距離的升序排序我的陣列嗎？

Answer 1

您可以在兩個對象之間提供一組比較代碼。 然后，NSArray將根據需要對塊進行多次調用來調用塊。

NSArray sortedArray = [yourUnsortedArray sortedArrayUsingComparator:^NSComparisonResult(id         obj1, id obj2) {
       /*some code to compare obj1 to obj2. 
       for instance, compare the distances of obj1 to obj2.
       Then return an  NSComparisonResult 
       (NSOrderedAscending, NSOrderedSame, NSOrderedDescending);*/
    }];

ps再次獲取一個可變數組，只需在返回的對象上調用mutableCopy 。

Answer 2

NSSortDescriptor * descLastname = [[NSSortDescriptor alloc] initWithKey:@"active" ascending:YES];
[livevideoparsingarray sortUsingDescriptors:[NSArray arrayWithObjects:descLastname, nil]];
 [descLastname release];
videoparsing = [livevideoparsingarray copy];

livevideoparsingarray是我的數組，我有排序和活動是我的標簽，這是我排序的數組。 你根據自己的要求改變。