ios - NSMutableArray 数据按距离排序

Question

我的 MutableArray 有问题。我的 TableView 中有数据数组，一切正常，但是当数据按距离排序并且我在单元格中选择一个项目时，它会在新的 View Controller 中显示不正确的数据。它显示没有排序的数据。这就像一个断开的链接)希望得到你的帮助)

我是 obj-c 的新手，所以我很抱歉)

这是我的代码:

       list = [[NSMutableArray alloc] init];

        [list addObject:@{@"name": @"Central office", @"address":@"наб. Обводного канала, д.66А", @"phone":@"+7 (812) 320-56-21 (многоканальный)", @"workTime":@"ПН-ПТ: с 9:30 до 18:30", @"email":@"mail@ibins.ru", @"payment":@"Принимаются к оплате пластиковые карты VISA и MasterCard", @"longitude":@30.336842, @"latitude":@59.913950}];

        [list addObject:@{@"name": @"Second office", @"address":@"ул. Камышовая, д.38", @"phone":@"+7 (812) 992-992-6; +7 (812) 456-26-43", @"workTime":@"Ежедневно: с 9:30 до 20:00", @"email":@"sever@ibins.ru", @"payment":@"Принимаются к оплате пластиковые карты VISA и MasterCard", @"longitude":@30.219863, @"latitude":@60.008805}];

        [list addObject:@{@"name": @"Third office", @"address":@"Street name", @"phone":@"phone number", @"workTime":@"Work time", @"email":@"email address", @"longitude":@30.294254, @"latitude":@60.028728}]; 

    [self constructList];
    [self constructPins];
    }



- (IBAction)switchDisplayType:(id)sender {
    [UIView beginAnimations:@"View Flip" context:nil];
    [UIView setAnimationDuration:0.80];
    [UIView setAnimationCurve:UIViewAnimationCurveEaseInOut];
    [UIView setAnimationTransition:UIViewAnimationTransitionFlipFromRight forView:self.view cache:NO];
    [UIView commitAnimations];

    if ([(UISegmentedControl*)sender selectedSegmentIndex] == 1) {
        map.hidden = YES;
        contentSV.hidden = NO;
    }
    else {
        map.hidden = NO;
        contentSV.hidden = YES;
    }
}

- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id <MKAnnotation>)annotation {
    static NSString* BridgeAnnotationIdentifier = @"bridgeAnnotationIdentifier";

    MKPinAnnotationView* customPinView = [[[MKPinAnnotationView alloc]
                                           initWithAnnotation:annotation reuseIdentifier:BridgeAnnotationIdentifier] autorelease];
    customPinView.pinColor = MKPinAnnotationColorRed;
    customPinView.animatesDrop = YES;
    customPinView.canShowCallout = YES;

    UIButton* rightButton = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];
   // NSLog(@"%@",rightButton);
    [rightButton addTarget:self
                    action:@selector(annotationButtonTapped:)
          forControlEvents:UIControlEventTouchUpInside];
    customPinView.rightCalloutAccessoryView = rightButton;
    return customPinView;//[kml viewForAnnotation:annotation];
}

- (void)annotationButtonTapped:(id)sender {
    DetailVC *sampleVC = [[DetailVC alloc] initWithNibName:@"DetailVC" bundle:[NSBundle mainBundle]];
    [self.navigationController pushViewController:sampleVC animated:YES];
    [sampleVC release];

    for (NSDictionary *dict in list) {
        if ([[dict valueForKey:@"name"] isEqualToString:selectedAnnTitle]) {
            [sampleVC updateViewWithDict:dict];
        }
    }
}



- (void)constructPins {
    for (NSDictionary *dict in list) {
        MKCoordinateRegion region;
        MKCoordinateSpan span;
        span.latitudeDelta = 0.3;
        span.longitudeDelta = 0.3;

        CLLocationCoordinate2D location;

        location.latitude = [[dict valueForKey:@"latitude"] floatValue];
        location.longitude = [[dict valueForKey:@"longitude"] floatValue];

        if (location.latitude == 0.0 && location.longitude == 0.0)
            return;

        region.span = span;
        region.center = location;

        MKPointAnnotation *point = [[MKPointAnnotation alloc] init];
        point.coordinate = location;
        point.title = [dict valueForKey:@"name"];

        [map addAnnotation:point];
        [map setRegion:region animated:YES];
    }
}

- (void)constructList {
    int n = 0;
    for (NSDictionary *dict in list) {
        UIView *container = [[UIView alloc] initWithFrame:CGRectMake(0, 100*n, 320, 100)];
        container.backgroundColor = [UIColor whiteColor];

        UIButton *button = [[UIButton alloc] initWithFrame:CGRectMake(0, 0, 320, 100)];
        button.tag = n;
        [button addTarget:self action:@selector(buttonTapped:) forControlEvents:UIControlEventTouchUpInside];
        [container addSubview:button];


        NSString *str = [NSString stringWithFormat:@"%@\nAddress: %@\nPhone: %@\nWork Time: %@", [dict valueForKey:@"name"], [dict valueForKey:@"address"], [dict valueForKey:@"phone"], [dict valueForKey:@"workTime"]];
        UILabel *nameLabel = [[UILabel alloc] initWithFrame:CGRectMake(10, 10, 300, 80)];
        nameLabel.textAlignment = NSTextAlignmentLeft;
        nameLabel.numberOfLines = 0;
        nameLabel.text = str;
        nameLabel.font = [UIFont fontWithName:@"HelveticaNeue" size:12.0];
        [container addSubview:nameLabel];


        UIView *separator = [[UIView alloc]initWithFrame:CGRectMake(0, 99, 320, 1)];
        separator.backgroundColor = [UIColor darkGrayColor];
        [container addSubview:separator];


        [contentSV addSubview:container];


        n++;
        contentSV.contentSize = CGSizeMake(0, 100*n);
    }
}

- (float)distanceBetweenLat1:(float)tlat1 lon1:(float)tlon1 lat2:(float)tlat2 lon2:(float)tlon2 {
    float result = 0.0;
    int R = 6371;

    float currentLatitude = tlat1;
    float currentLongtitude = tlon1;

    float lat2 = tlat2;
    float lon2 = tlon2;

    float dLat = (lat2-currentLatitude)*M_PI/180;
    float dLon = (lon2-currentLongtitude)*M_PI/180;
    float nlLat = currentLatitude*M_PI/180;
    lat2 = lat2*M_PI/180;

    float a = sin(dLat/2) * sin(dLat/2) +  sin(dLon/2) * sin(dLon/2) * cos(nlLat) * cos(lat2);
    float c = 2 * atan2(sqrt(a), sqrt(1-a));
    result = R * c;

    return result;
}

- (void)mapView:(MKMapView *)mapView didSelectAnnotationView:(MKAnnotationView *)view {
    selectedAnnTitle = [view.annotation title];

    return;

    DetailVC *sampleVC = [[DetailVC alloc] initWithNibName:@"DetailVC" bundle:[NSBundle mainBundle]];
    [self.navigationController pushViewController:sampleVC animated:YES];


    NSString *ttl = [view.annotation title];

    for (NSDictionary *dict in list) {
        if ([[dict valueForKey:@"name"] isEqualToString:ttl]) {
            [sampleVC updateViewWithDict:dict];
        }
    }

    [map deselectAnnotation:view.annotation animated:NO];
}

- (void)buttonTapped:(id)sender {
    DetailVC *sampleVC = [[DetailVC alloc] initWithNibName:@"DetailVC" bundle:[NSBundle mainBundle]];
    [self.navigationController pushViewController:sampleVC animated:YES];


    int n = 0;
    for (NSDictionary *dict in list) {
        if (n == [sender tag]) {
            [sampleVC updateViewWithDict:dict];
        }
        n++;
    }
}

- (void)mapView:(MKMapView *)mapView didUpdateUserLocation:(MKUserLocation *)userLocation {
    NSLog(@"didUpdateUserLocation");

    MKAnnotationView* annotationView = [mapView viewForAnnotation:userLocation];
    annotationView.canShowCallout = NO;

    if (!userLocationUpdated) {
        if (userLocation.coordinate.latitude > 0.1 && userLocation.coordinate.longitude > 0.1) {
         //   NSLog(@"SORT BY DISTANCE");

            userLocationUpdated = YES;

            for (int i = 0; i < [list count]; i++) {
                NSMutableDictionary *record = [[NSMutableDictionary alloc] initWithDictionary:[list objectAtIndex:i]];

                float latitude = [[record valueForKey:@"latitude"] floatValue];
                float longitude = [[record valueForKey:@"longitude"] floatValue];

                float dist = [self distanceBetweenLat1:map.userLocation.coordinate.latitude lon1:map.userLocation.coordinate.longitude lat2:latitude lon2:longitude];
                NSNumber *distN = [NSNumber numberWithFloat:dist];
                [record setObject:distN forKey:@"distance"];

              [list replaceObjectAtIndex:i withObject:record];
            }

            NSSortDescriptor *descriptor = [[NSSortDescriptor alloc] initWithKey:@"distance" ascending:YES];
            NSArray *itemsListSorted = [[NSArray alloc] initWithArray:list];
            itemsListSorted = [itemsListSorted sortedArrayUsingDescriptors:[NSArray arrayWithObjects:descriptor,nil]];

            for (UIView *view in contentSV.subviews) {
                [view removeFromSuperview];
            }

            for (int i = 0; i < [itemsListSorted count]; i++) {
                UIView *container = [[UIView alloc] initWithFrame:CGRectMake(0, 100*i, 320, 100)];
                container.backgroundColor = [UIColor whiteColor];

                UIButton *button = [[UIButton alloc] initWithFrame:CGRectMake(0, 0, 320, 100)];
                button.tag = i;
                [button addTarget:self action:@selector(buttonTapped:) forControlEvents:UIControlEventTouchUpInside];
                [container addSubview:button];


                NSString *str = [NSString stringWithFormat:@"%@\nAddress: %@\nPhone: %@\nWorkTime: %@", [[itemsListSorted objectAtIndex:i] valueForKey:@"name"], [[itemsListSorted objectAtIndex:i] valueForKey:@"address"], [[itemsListSorted objectAtIndex:i] valueForKey:@"phone"], [[itemsListSorted objectAtIndex:i] valueForKey:@"workTime"]];
                UILabel *nameLabel = [[UILabel alloc] initWithFrame:CGRectMake(10, 10, 300, 80)];
                nameLabel.textAlignment = NSTextAlignmentLeft;
                nameLabel.numberOfLines = 0;
                nameLabel.text = str;
                nameLabel.font = [UIFont fontWithName:@"HelveticaNeue" size:12.0];
                [container addSubview:nameLabel];


                UILabel *distanceLabel = [[UILabel alloc] initWithFrame:CGRectMake(10, 2, 300, 21)];
                distanceLabel.textAlignment = NSTextAlignmentRight;
                distanceLabel.text = [NSString stringWithFormat:@"%.1f км", [[[itemsListSorted objectAtIndex:i] valueForKey:@"distance"] floatValue]];
                distanceLabel.font = [UIFont fontWithName:@"HelveticaNeue" size:12.0];
                distanceLabel.textColor = [UIColor lightGrayColor];
                [container addSubview:distanceLabel];


                UIView *separator = [[UIView alloc]initWithFrame:CGRectMake(0, 99, 320, 1)];
                separator.backgroundColor = [UIColor darkGrayColor];
                [container addSubview:separator];


                [contentSV addSubview:container];


                contentSV.contentSize = CGSizeMake(0, 100*(i+1));
            }
        }
    }
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
}

@end

Answer 1

虽然此代码存在许多问题(其中最少的是距离计算的一些小精度问题)，问题不在于距离计算。

详细 View Controller 显示不正确的数据，因为它从 list 数组中获得数据，该数组不是本身按距离排序。

在 didUpdateUserLocation 委托(delegate)方法中，list 的内容被复制到名为 itemsListSorted 的本地数组。

只有 itemsListSorted 数组按距离排序，然后使用此本地 数组更新显示。

但原始的 list 数组(buttonTapped 方法将其用作发送到详细 View Controller 的数据源)从不 已更新。

因此，如果“Central Office”位于 list 中的索引 0，但在 itemsListSorted 中移动到索引 2，则显示会显示正确的位置，但是当您点击它时，buttonTapped 方法从 list 数组发送索引 2 处的项目，该数组不有“Central Office”(它仍然在索引 0 列表).

解决此问题的一种方法是停止使用本地数组并直接对 list 数组进行排序。

在 didUpdateUserLocation 中，您可以替换这两行:

NSArray *itemsListSorted = [[NSArray alloc] initWithArray:list];
itemsListSorted = [itemsListSorted sortedArrayUsingDescriptors:[NSArray arrayWithObjects:descriptor,nil]];

用这个:

[list sortUsingDescriptors:[NSArray arrayWithObjects:descriptor,nil]];

然后用 list 替换所有对 itemsListSorted 的引用。

---

关于代码的其他问题，没有足够的空间将它们全部指出或在一个答案中解释它们。然而，这里只是一些亮点:

• 不要手动创建“表格 View ”，而是使用实际的 UITableView。
• 不要手动计算坐标之间的距离，而是使用 CLLocation 类中的 distanceFromLocation 方法或 MKMetersBetweenMapPoints功能。
• 在 viewForAnnotation 中，如果 annotation 是 MKUserLocation 类型，您应该返回 nil 否则它将显示为红色别针和其他别针一样。
• 使用 ARC 而不是手动内存管理。