本文介绍了添加多个注释iPhone MapView类是缓慢的的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我有code，需要一个标题和一个位置的地址，然后得到谷歌地图坐标CSV文件，然后添加注释。它的工作原理，但是当我想一次冻结约30-40秒加50个或更多注释，然后显示批注，所以我想知道的是为什么我搞砸了内存管理，这就是为什么它这么慢，什么其他？我可以加快步伐？
下面是code：
- （无效）addAnnotation：（* NSString的）annoTitle：（* NSString的）annoAddress
{
* NSString的地址= annoAddress; * NSString的urlString = [的NSString stringWithFormat：@http://maps.google.com/maps/geo?q=%@&output=csv，[地址stringByAddingPercentEscapesUsingEncoding：NSUTF8StringEncoding]];
的NSString * locationString = [NSString的stringWithContentsOfURL：[NSURL URLWithString：urlString]];
NSArray的*时listItems = [locationString componentsSeparatedByString：@]; 浮langcoord = [[listItems中objectAtIndex：2]的floatValue];
浮longcoord = [[listItems中objectAtIndex：3]的floatValue]; CLLocationCoordinate2D坐标= CLLocationCoordinate2DMake（langcoord，longcoord）; //与当前数据创建的MapPoint的一个实例
注释*注释= [[译注页头] initWithCoordinate：坐标标题：annoTitle]; //将它添加到地图视图
[图形页面addAnnotation：注释]。 //的MKMapView保留了注释，所以我们可以释放它
[注释发布]
}
解决方案
下面的方法使用了上MapKit多插针。
- （无效）viewWillAppear中：动画（BOOL）{ NSArray的* AS = [NSArray的arrayWithArray：[报告objectAtIndex：0];
的for（int i = 0; I＆LT; AS计数];我++）{
将*家= [[[广场ALLOC] INIT]自动释放];
home.name = [[AS objectAtIndex：我] valueForKey：@意见];
home.latitude = [[[AS objectAtIndex：我] valueForKey：@纬度]的floatValue];
home.longitude = [[[AS objectAtIndex：我] valueForKey：@经度]的floatValue];
valueForKey：@纬度]的floatValue]，[[[AS objectAtIndex：ⅰ] valueForKey：@经度]的floatValue]]; 标*从= [[[标页头] initWithPlace：家居】自动释放];
[图形页面addAnnotation：来自];
}
[个体经营centerMap] [UIApplication的sharedApplication] .networkActivityIndicatorVisible = NO;
}
集中式地图两个引脚之间
- （无效）centerMap
{
MKCoordinateRegion区域;
CLLocationDegrees maxLat = -90;
CLLocationDegrees maxLon = -180;
CLLocationDegrees minLat = 120;
CLLocationDegrees MINLON = 150;
NSArray的* TEMP = [NSArray的arrayWithArray：[NSArray的arrayWithArray：[报告objectAtIndex：0]]];
的for（int i = 0; I＆LT;温度计数];我++）{
将*家= [[[广场ALLOC] INIT]自动释放];
home.latitude = [[[温度objectAtIndex：我] valueForKey：@纬度]的floatValue];
home.longitude = [[[温度objectAtIndex：我] valueForKey：@经度]的floatValue]; 标*从= [[[标页头] initWithPlace：家居】自动释放]; CLLocation * currentLocation =（CLLocation *）FROM;
如果（currentLocation.coordinate.latitude＆GT; maxLat）
maxLat = currentLocation.coordinate.latitude;
如果（currentLocation.coordinate.latitude＆LT; minLat）
minLat = currentLocation.coordinate.latitude;
如果（currentLocation.coordinate.longitude＆GT; maxLon）
maxLon = currentLocation.coordinate.longitude;
如果（currentLocation.coordinate.longitude＆LT; MINLON）
MINLON = currentLocation.coordinate.longitude; region.center.latitude =（maxLat + minLat）/ 2;
region.center.longitude =（maxLon + MINLON）/ 2;
region.span.latitudeDelta = maxLat - minLat;
region.span.longitudeDelta = maxLon - MINLON;
}
[图形页面setRegion：地区动画：是];
}
在这里定义多个注释。
- （MKAnnotationView *）的MapView：（*的MKMapView）的地图viewForAnnotation：（ID＆LT; MKAnnotation＆GT;）注释
{ 如果（注释== mapView.userLocation）
回零; MKPinAnnotationView *销=（MKPinAnnotationView *）[图形页面dequeueReusableAnnotationViewWithIdentifier：@ASDF]; 如果（PIN ==无）
引脚= [[[MKPinAnnotationView页头] initWithAnnotation：注释reuseIdentifier：@ASDF]自动释放];
其他
pin.annotation =注释;
pin.userInteractionEnabled = YES;
*的UIButton = disclosureButton [UIButton的buttonWithType：UIButtonTypeDetailDisclosure];
[disclosureButton SETFRAME：CGRectMake（0，0，30，30）]; pin.rightCalloutAccessoryView = disclosureButton;
pin.pinColor = MKPinAnnotationColorRed;
pin.animatesDrop = YES;
[销的setEnabled：YES];
[销setCanShowCallout：YES];
回复销;
}
I have code that takes a title and an address of a location,then get coordinates from google maps csv, then add annotation. It works, but when I want to add 50 or more annotation at once it freezes for about 30-40 seconds and then displays annotations, so what I want to know is did I screw up memory management and that's why it's so slow, or something else? Can I speed it up?
Here is the code:
- (void) addAnnotation: (NSString*) annoTitle: (NSString*) annoAddress
{
NSString *address = annoAddress;
NSString *urlString = [NSString stringWithFormat:@"http://maps.google.com/maps/geo?q=%@&output=csv", [address stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]];
NSString *locationString = [NSString stringWithContentsOfURL:[NSURL URLWithString:urlString]];
NSArray *listItems = [locationString componentsSeparatedByString:@","];
float langcoord = [[listItems objectAtIndex:2] floatValue];
float longcoord = [[listItems objectAtIndex:3] floatValue];
CLLocationCoordinate2D coord = CLLocationCoordinate2DMake(langcoord, longcoord);
// Create an instance of MapPoint with the current data
Annotation *annotation = [[Annotation alloc] initWithCoordinate:coord title:annoTitle];
// Add it to the map view
[mapView addAnnotation:annotation];
// MKMapView retains its annotations, so we can release it
[annotation release];
}
解决方案
Following methods are use for the multiple pin on MapKit.
-(void)viewWillAppear:(BOOL)animated {
NSArray *AS=[NSArray arrayWithArray:[reports objectAtIndex:0]];
for (int i=0; i<[AS count]; i++) {
Place* home = [[[Place alloc] init] autorelease];
home.name = [[AS objectAtIndex:i] valueForKey:@"comments"];
home.latitude = [[[AS objectAtIndex:i] valueForKey:@"latitude"]floatValue];
home.longitude = [[[AS objectAtIndex:i] valueForKey:@"longitude"]floatValue];
valueForKey:@"latitude"]floatValue],[[[AS objectAtIndex:i] valueForKey:@"longitude"]floatValue]];
PlaceMark* from = [[[PlaceMark alloc] initWithPlace:home] autorelease];
[mapView addAnnotation:from];
}
[self centerMap];
[UIApplication sharedApplication].networkActivityIndicatorVisible = NO;
}
Centralized Map between two pins
-(void) centerMap
{
MKCoordinateRegion region;
CLLocationDegrees maxLat = -90;
CLLocationDegrees maxLon = -180;
CLLocationDegrees minLat = 120;
CLLocationDegrees minLon = 150;
NSArray *temp=[NSArray arrayWithArray:[NSArray arrayWithArray:[reports objectAtIndex:0]]];
for (int i=0; i<[temp count];i++) {
Place* home = [[[Place alloc] init] autorelease];
home.latitude = [[[temp objectAtIndex:i] valueForKey:@"latitude"]floatValue];
home.longitude =[[[temp objectAtIndex:i] valueForKey:@"longitude"]floatValue];
PlaceMark* from = [[[PlaceMark alloc] initWithPlace:home] autorelease];
CLLocation* currentLocation = (CLLocation*)from ;
if(currentLocation.coordinate.latitude > maxLat)
maxLat = currentLocation.coordinate.latitude;
if(currentLocation.coordinate.latitude < minLat)
minLat = currentLocation.coordinate.latitude;
if(currentLocation.coordinate.longitude > maxLon)
maxLon = currentLocation.coordinate.longitude;
if(currentLocation.coordinate.longitude < minLon)
minLon = currentLocation.coordinate.longitude;
region.center.latitude = (maxLat + minLat) / 2;
region.center.longitude = (maxLon + minLon) / 2;
region.span.latitudeDelta = maxLat - minLat;
region.span.longitudeDelta = maxLon - minLon;
}
[mapView setRegion:region animated:YES];
}
Define the multiple annotation here.
- (MKAnnotationView *)mapView:(MKMapView *)map viewForAnnotation:(id <MKAnnotation>)annotation
{
if (annotation == mapView.userLocation)
return nil;
MKPinAnnotationView *pin = (MKPinAnnotationView *) [mapView dequeueReusableAnnotationViewWithIdentifier: @"asdf"];
if (pin == nil)
pin = [[[MKPinAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier: @"asdf"] autorelease];
else
pin.annotation = annotation;
pin.userInteractionEnabled = YES;
UIButton *disclosureButton = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];
[disclosureButton setFrame:CGRectMake(0, 0, 30, 30)];
pin.rightCalloutAccessoryView = disclosureButton;
pin.pinColor = MKPinAnnotationColorRed;
pin.animatesDrop = YES;
[pin setEnabled:YES];
[pin setCanShowCallout:YES];
return pin;
}
More details and download the sample code here.
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