[英]Building MapView Annotations is very slow
我有一個應用程序,可在MapView中顯示約100個注釋(帶有自定義圖釘圖像,標注附件和注釋圖像)。 在構建注釋時,我在注釋和建築物之間存儲了鏈接,因此我可以分配正確的建築物並隨后打開正確的序列。
在iOS 6中,它們的構建速度非常快,我在添加它們時也啟用了動畫,因此一個圖釘掉到了另一個圖釘上,但是在iOS7中使用Apple Maps不再可用(?)。 現在在我的iPhone 4S上構建這100條注釋需要1秒鍾,這太長了。 無論如何,有沒有改進代碼?
- (void)viewDidLoad
...
//creating annotations
annotationlink = [[NSMutableArray alloc] init];
for (int i = 0; i < data.count; i++) {
NSDictionary *dataItem = [data objectAtIndex:i];
//storing annotation in array for link
Annotation *buildingannotation = [[Annotation alloc] init];
NSNumber *index = [NSNumber numberWithInteger:i];
NSDictionary *dict = [NSDictionary dictionaryWithObjectsAndKeys:index, indexKey, buildingannotation, annotationKey, nil];
[annotationlink addObject:dict];
buildingannotation.title = [dataItem objectForKey:@"Building"];
buildingannotation.subtitle = [dataItem objectForKey:@"Info"];
MKCoordinateRegion buildingcoordinates;
buildingcoordinates.center.latitude = [[dataItem objectForKey:@"Latitude"] floatValue];
buildingcoordinates.center.longitude = [[dataItem objectForKey:@"Longitude"] floatValue];
buildingannotation.coordinate = buildingcoordinates.center;
[self.mapView addAnnotation:buildingannotation];
}
- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id <MKAnnotation>)annotation
{
if ([annotation isKindOfClass:[MKUserLocation class]]){
return nil;
}
MKAnnotationView *pinView = (MKAnnotationView *)
[self.mapView dequeueReusableAnnotationViewWithIdentifier:pinIdentifier];
MKAnnotationView *customAnnotationView = [[MKAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:pinIdentifier];
customAnnotationView.canShowCallout = YES;
//right button to detail view
UIButton* disclosureButton = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];
customAnnotationView.rightCalloutAccessoryView = disclosureButton;
//left button for image
NSInteger *buildingindex = [self getIndex:annotation];
NSDictionary *dataItem = [data objectAtIndex:buildingindex];
NSString* filename = [dataItem objectForKey:@"Thumb"];
filename = [filename stringByAppendingString:@"@2x.jpg"];
NSString* resourceimagePath = [resourcePath stringByAppendingPathComponent:filename];
Image = [UIImage imageWithContentsOfFile:resourceimagePath];
UIImageView *AnnotationThumb = [[UIImageView alloc] initWithImage:Image];
AnnotationThumb.frame = CGRectMake(0, 0, 31, 31);
customAnnotationView.leftCalloutAccessoryView = AnnotationThumb;
//annotation image
customAnnotationView.image = [UIImage imageNamed:@"Annotation_white.png"];
return customAnnotationView;
return pinView;
}
以下函數使用nspredicate獲取當前注釋的索引,以使用字典過濾數組。 這樣的優點是事實,當calloutAccessoryControlTapped時,我也可以使用它:
-(NSInteger*) getIndex:(Annotation*)searchannotation
{
NSPredicate *predicate = [NSPredicate predicateWithFormat:@"%K == %@", annotationKey, searchannotation];
NSArray *filteredarray = [annotationlink filteredArrayUsingPredicate:predicate];
NSDictionary *building = [filteredarray objectAtIndex:0];
NSInteger *buildingIndex = [[building objectForKey:indexKey] integerValue];
return buildingIndex;
}
使用iPhone 4S,在加載視圖后的1.14秒內建立了最后一個引腳。
如果我手動搜索注釋鏈接數組而不是使用nspredicate函數,例如:
//left button for image
int buildingIndex;
for (int i = 0; i < annotationlink.count; i++) {
NSDictionary *annotationDict = [annotationlink objectAtIndex:i];
if ([[annotationDict objectForKey:annotationKey] isEqual:annotation]) {
buildingIndex= [[annotationDict objectForKey:indexKey] integerValue];
i = annotationlink.count;
}
}
NSDictionary *dataItem = [data objectAtIndex:buildingIndex];
日志顯示最后一個引腳建立在viewDidLoad之后的1.89秒處。
如果我在viewDidApper中而不是viewDidLoad中創建注釋,則視圖會立即顯示為偏離路線,但是背景需要一些時間才能加載,因此在放下銷釘之前,所有部件都是灰色的,這也不是很好。
謝謝安娜的建議! 我實現了如下改進:
Annotation.h:
#import <MapKit/MKAnnotation.h>
@interface Annotation : NSObject <MKAnnotation> {}
@property(nonatomic, assign) CLLocationCoordinate2D coordinate;
@property(nonatomic, copy) NSString *title;
@property(nonatomic, copy) NSString *subtitle;
@property NSInteger *ID;
@end
Annotation.m:
#import "Annotation.h"
@implementation Annotation
@synthesize coordinate, title, subtitle, ID;
@end
ViewDidAppear:
//creating annotations
for (int i = 0; i < data.count; i++) {
NSDictionary *dataItem = [data objectAtIndex:i];
Annotation *buildingannotation = [[Annotation alloc] init];
buildingannotation.ID = i;
buildingannotation.title = [dataItem objectForKey:@"Building"];
buildingannotation.subtitle = [dataItem objectForKey:@"Subtitle"];
MKCoordinateRegion buildingcoordinates;
buildingcoordinates.center.latitude = [[dataItem objectForKey:@"Latitude"] floatValue];
buildingcoordinates.center.longitude = [[dataItem objectForKey:@"Longitude"] floatValue];
buildingannotation.coordinate = buildingcoordinates.center;
[self.mapView addAnnotation:buildingannotation];
}
viewForAnnotation:
- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id <MKAnnotation>)annotation
{
if ([annotation isKindOfClass:[MKUserLocation class]]){
return nil;
}
MKAnnotationView *pinView = (MKAnnotationView *)
[self.mapView dequeueReusableAnnotationViewWithIdentifier:pinIdentifier];
if (pinView == nil) {
MKAnnotationView *customAnnotationView = [[MKAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:pinIdentifier];
customAnnotationView.canShowCallout = YES;
//right button to detail view
UIButton* disclosureButton = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];
customAnnotationView.rightCalloutAccessoryView = disclosureButton;
//left button for image
Annotation *buildingAnnotation = (Annotation *)annotation;
NSInteger *buildingindex = buildingAnnotation.ID;
NSString *filePath = [thumbname objectAtIndex:buildingindex];
UIImageView *AnnotationThumb = [[UIImageView alloc] initWithImage:[UIImage imageWithContentsOfFile:filePath]];
AnnotationThumb.frame = CGRectMake(0, 0, 31, 31);
customAnnotationView.leftCalloutAccessoryView = AnnotationThumb;
//annotation image
customAnnotationView.image = [UIImage imageNamed:@"Annotation_white.png"];
return customAnnotationView;
} else {
pinView.annotation = annotation;
}
return pinView;
}
大喊:
- (void)mapView:(MKMapView *)mapView annotationView:(MKAnnotationView *)view calloutAccessoryControlTapped:(UIControl *)control
{
Annotation *buildingAnnotation = (Annotation *)view.annotation;
selectedbuilding = buildingAnnotation.ID;
[self performSegueWithIdentifier:@"DetailViewController" sender:self];
}
仍需要一些時間來顯示所有注釋。 有機會進一步改進代碼嗎?
我更新了關於Anna的回復和PhotosByLocation示例應用程序的vievForAnnotation函數。 它現在可以工作,我希望這是實現重用的正確方法...
- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id <MKAnnotation>)annotation
{
if ([annotation isKindOfClass:[MKUserLocation class]]){
return nil;
}
MKAnnotationView *buildingAnnotationView = (MKAnnotationView *) [mapView dequeueReusableAnnotationViewWithIdentifier:pinIdentifier];
if (buildingAnnotationView) {
[buildingAnnotationView prepareForReuse];
} else {
buildingAnnotationView = [[MKAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:pinIdentifier];
buildingAnnotationView.canShowCallout = YES;
//right button to detail view
UIButton* disclosureButton = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];
buildingAnnotationView.rightCalloutAccessoryView = disclosureButton;
//annotation image
buildingAnnotationView.image = [UIImage imageNamed:@"Annotation_white.png"];
}
//left button for image
Annotation *buildingAnnotation = (Annotation *)annotation;
NSInteger *buildingindex = buildingAnnotation.ID;
NSString *filePath = [thumbname objectAtIndex:buildingindex];
UIImageView *AnnotationThumb = [[UIImageView alloc] initWithImage:[UIImage imageWithContentsOfFile:filePath]];
AnnotationThumb.frame = CGRectMake(0, 0, 31, 31);
buildingAnnotationView.leftCalloutAccessoryView = AnnotationThumb;
return buildingAnnotationView;
}
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.