Question

我已经使用这行代码在MkMapView上添加了超过 2000 自定义注释。然后第一次收到内存警告和应用程序崩溃。

 -(MKAnnotationView *)mapView:(MKMapView *)mV viewForAnnotation:(id   <MKAnnotation>)annotation
{

    if([annotation isKindOfClass:[MKUserLocation class]])
    {
        return nil;
    }
    //MKAnnotationView *annotationView = nil;
   else if ([annotation isKindOfClass:[MyAnnotation class]])
    {
        MKAnnotationView *annotationView = nil;
        static NSString *identifier = @"identifier";
        annotationView = (MKAnnotationView *)[mapViewForMapScreen dequeueReusableAnnotationViewWithIdentifier:identifier];
        if (annotationView) {
            annotationView.annotation = annotation;
        } else {
            annotationView = [[MKAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:identifier];
            annotationView.canShowCallout = YES;
        }

        MyAnnotation *anno=(MyAnnotation*)annotation;
        tagForAnnotation=(int)anno.tag;

        if (arrayForLatLong.count!=0)
        {
            if ([[[arrayForLatLong valueForKey:@"sourceType"]  objectAtIndex:tagForAnnotation] isEqualToString:@"INSTAGRAM"])
            {
                annotationView.image=[UIImage imageNamed:@"instagram.png"];
                annotationView.frame=CGRectMake(0, 0, 16, 22);
            }
            else if([[[arrayForLatLong valueForKey:@"sourceType"]  objectAtIndex:tagForAnnotation] isEqualToString:@"TWITTER"])
            {
                annotationView.image=[UIImage imageNamed:@"twt_pin.png"];
                annotationView.frame=CGRectMake(0, 0, 16, 22);
            }

            else if ([[[arrayForLatLong valueForKey:@"sourceType"]  objectAtIndex:tagForAnnotation] isEqualToString:@"YOUTUBE"])
            {
                annotationView.image=[UIImage imageNamed:@"youtube.png"];
                annotationView.frame=CGRectMake(0, 0, 16, 22);
            }
            else if ([[[arrayForLatLong valueForKey:@"sourceType"]  objectAtIndex:tagForAnnotation] isEqualToString:@"MEETUP"])
            {
                annotationView.image=[UIImage imageNamed:@"meetup_iphone"];
                annotationView.frame=CGRectMake(0, 0, 16, 22);
            }
            else if ([[[arrayForLatLong valueForKey:@"sourceType"]  objectAtIndex:tagForAnnotation] isEqualToString:@"FLICKR"])
            {
                annotationView.image=[UIImage imageNamed:@"flikr.png"];
                annotationView.frame=CGRectMake(0, 0, 16, 22);
            }
            else if ([[[arrayForLatLong valueForKey:@"sourceType"]  objectAtIndex:tagForAnnotation] isEqualToString:@"VK"])
            {
                annotationView.image=[UIImage imageNamed:@"vk1"];
                annotationView.frame=CGRectMake(0, 0, 16, 22);
            }
        }
        infoButton=[[AsyncImageView alloc]init];
        if ([[[[[arrayForLatLong objectAtIndex:tagForAnnotation] valueForKey:@"user"] valueForKey:@"profilePic"] valueForKey:@"small"] isEqualToString:@""]){
            if ([[[[[arrayForLatLong objectAtIndex:tagForAnnotation] valueForKey:@"user"] valueForKey:@"profilePic"] valueForKey:@"medium"] isEqualToString:@""]){
                if ([[[[[arrayForLatLong objectAtIndex:tagForAnnotation] valueForKey:@"user"] valueForKey:@"profilePic"] valueForKey:@"large"] isEqualToString:@""]) {
                    [infoButton setImage:[UIImage imageNamed:@"profile"] forState:UIControlStateNormal];
                }else{
                    [infoButton setImageURL:[NSURL URLWithString:[[[[arrayForLatLong objectAtIndex:tagForAnnotation] valueForKey:@"user"] valueForKey:@"profilePic"] valueForKey:@"large"]]];
                }
            }else{
                [infoButton setImageURL:[NSURL URLWithString:[[[[arrayForLatLong objectAtIndex:tagForAnnotation] valueForKey:@"user"] valueForKey:@"profilePic"] valueForKey:@"medium"]]];
            }
        }else{
            [infoButton setImageURL:[NSURL URLWithString:[[[[arrayForLatLong objectAtIndex:tagForAnnotation] valueForKey:@"user"]valueForKey:@"profilePic"] valueForKey:@"small"]]];
        }
        [infoButton setFrame:CGRectMake(20,10,30,30)];
        infoButton.layer.cornerRadius=infoButton.frame.size.height/2.0;
        infoButton.layer.masksToBounds = YES;
        [infoButton addTarget:self action:@selector(actionForProfileImage:) forControlEvents:UIControlEventTouchUpInside];
        infoButton.layer.borderWidth=1.0;
        infoButton.layer.borderColor=[UIColor grayColor].CGColor;
        infoButton.tag=tagForAnnotation;


        //Followed Button:----
        AsyncImageView *followedBtn=[[AsyncImageView alloc]init];
        [followedBtn setFrame:CGRectMake(2,8,17,17)];
        followedBtn.tag=tagForAnnotation;
        if ([[[[arrayForLatLong objectAtIndex:tagForAnnotation] valueForKey:@"user"] valueForKey:@"isFollowed"] boolValue]==0 ){
            [followedBtn setBackgroundImage:[UIImage imageNamed:@"star_grey.png"] forState:UIControlStateNormal];
        }else{
            [followedBtn setBackgroundImage:[UIImage imageNamed:@"star_blue.png"] forState:UIControlStateNormal];
        }
        [followedBtn addTarget:self action:@selector(actionForStarImage:) forControlEvents:UIControlEventTouchUpInside];
        UIView*viewForCallOut=[[UIView alloc] initWithFrame:CGRectMake(0, 0,50, 50)];
        [viewForCallOut addSubview:infoButton];
        //[viewForCallOut addSubview:followedBtn];
        annotationView.leftCalloutAccessoryView=viewForCallOut;
        annotationView.canShowCallout = YES;
        return annotationView;
    }


    return nil;
}

如果我有任何错误，请检查我的代码然后请告诉我。提前致谢

Answer 1

当您有大量数据点导致大量注释时，一种好方法是聚类数据点并为每个群集添加注释。随着地图缩放到群集中，您将表示群集的注释替换为群集中数据点的注释。缩小群集时，可以使用表示群集的注释替换表示数据点的注释。这种方法减少了注释的总数，使数据更容易理解。 fromValue和This SO question会为您提供有关群集的更多信息。

添加自定义注释然后app crashed-ios

1 个答案: