加载注释到地图视图从Plist不工作 [英] Loading Annotations to Map View From Plist Not Working
本文介绍了加载注释到地图视图从Plist不工作的处理方法，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
Hey fellas, so I am able to display annotations (2) from the source code found at this link (and within the commented-out code post below).
但是，我从plist加载注释信息并加载它正确地（通过调试器确认）到mapView中，但由于某种原因，当我在模拟器中运行应用程序时，注释拒绝显示。以下是相关代码：
However, I load annotation information from a plist and load it correctly (confirmed via debugger) into mapView but for some reason the annotations refuse to show when I run the app in the simulator. Here is the relevant code:
注释标题：
#import <Foundation/Foundation.h>
#import <MapKit/MapKit.h>
@interface ArboretumAnnotation : NSObject <MKAnnotation> {
NSString *title;
NSString *subtitle;
UIImage *image;
CLLocationCoordinate2D coordinate;
}
@property (nonatomic, retain) NSString *title;
@property (nonatomic, retain) NSString *subtitle;
@property (nonatomic, retain) UIImage *image;
@property (nonatomic) CLLocationCoordinate2D coordinate;
@end
注释实现：
#import "ArboretumAnnotation.h"
@implementation ArboretumAnnotation
@synthesize title;
@synthesize subtitle;
@synthesize image;
@synthesize coordinate;
-(id)init{
self = [super init];
if(!self)
return nil;
self.title = nil;
self.subtitle = nil;
self.image = nil;
return self;
}
-(id)initWithCoordinate:(CLLocationCoordinate2D)inCoord{
self = [self init];
self.coordinate = inCoord;
return self;
}
@end
MapViewController标题：
MapViewController header:
#import <UIKit/UIKit.h>
#import <MapKit/MapKit.h>
@interface MapViewController : UIViewController <MKMapViewDelegate> {
MKMapView *mapView;
}
@property (nonatomic, retain) IBOutlet MKMapView *mapView;
- (void)showCurrentLocationButtonTapped:(id)sender;
- (void)loadAnnotations; //helper function that loads all overlay data from plist
- (void)loadOverlays; //helper function that loads all overlay data from plist
- (void)handleGesture:(UILongPressGestureRecognizer *)gestureRecognizer;
@end
MapViewController实现：
MapViewController implementation:
#import "MapViewController.h"
#import "MKMapView+ZoomLevel.h"
#import "ArboretumRegionOverlay.h"
#import "ArboretumAnnotation.h"
#import "ArboretumAnnotationView.h"
#import "LocationDetailViewController.h"
#define UCD_LATITUDE 38.531728
#define UCD_LONGITUDE -121.755327
@implementation MapViewController
@synthesize mapView;
// Implement viewDidLoad to do additional setup after loading the view, typically from a nib.
- (void)viewDidLoad {
[super viewDidLoad];
//mapView = [[MKMapView alloc] initWithFrame:self.view.bounds];
mapView.delegate = self;
self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"Location Info" style:UIBarButtonItemStylePlain target:self action:nil];
self.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:100 target:self action:@selector(showCurrentLocationButtonTapped:)];
[self loadAnnotations];
[self loadOverlays];
[mapView setNeedsDisplay];
/*
//TEST LOAD AN ANNOTATION
//MKPointAnnotation *testAnnot = [[MKPointAnnotation alloc] init];
ArboretumAnnotation *arboAnnot = [[ArboretumAnnotation alloc] init];
CLLocationCoordinate2D workingCoord;
workingCoord.latitude = 38.529977;
workingCoord.longitude = -121.76;
[arboAnnot setCoordinate:workingCoord];
[arboAnnot setTitle:@"Test Title"];
[arboAnnot setSubtitle:@"Test Subtitle"];
[mapView addAnnotation:arboAnnot];
[arboAnnot release];
ArboretumAnnotation *arboAnnot2 = [[ArboretumAnnotation alloc] init];
CLLocationCoordinate2D workingCoord2;
workingCoord2.latitude = 38.531594;
workingCoord2.longitude = -121.762129;
[arboAnnot2 setCoordinate:workingCoord2];
[arboAnnot2 setTitle:@"Test A really really really really long title Title2"];
[arboAnnot2 setSubtitle:@"Test A really really really really long sub Subtitle2"];
[mapView addAnnotation:arboAnnot2];
[arboAnnot2 release];
*/
//detects press gestures used for producing region overlay callout
UILongPressGestureRecognizer *lpgr = [[UILongPressGestureRecognizer alloc]
initWithTarget:self action:@selector(handleGesture:)];
lpgr.minimumPressDuration = 0.3; //user must press for 1 second
//[mapView addGestureRecognizer:lpgr];
[lpgr release];
//initialize the map view (location and zoom)
CLLocationCoordinate2D centerCoord = { UCD_LATITUDE, UCD_LONGITUDE };
[mapView setCenterCoordinate:centerCoord zoomLevel:13 animated:NO];
}
- (void)showCurrentLocationButtonTapped:(id)sender {
NSLog(@"Showing current location.");
if ([mapView showsUserLocation] == NO) {
[mapView setShowsUserLocation:YES];
}
[mapView setCenterCoordinate:mapView.centerCoordinate zoomLevel:13 animated:YES];
}
- (void)loadAnnotations{
//retrieve path of plist file and populate relevant types with its information
NSString *plistPath = [[NSBundle mainBundle] pathForResource:@"ArboretumGardens" ofType:@"plist"];
NSDictionary *rootOfArboDataPlistDict = [[NSDictionary alloc] initWithContentsOfFile:plistPath];
NSMutableArray *arboAnnotations = [[NSMutableArray alloc] init];
for (NSString *key in rootOfArboDataPlistDict) {
NSMutableDictionary *arboDict = [rootOfArboDataPlistDict objectForKey:key];
//array containing annotation information: latitude, longitude, title, subtitle(see PermitData.plist)
NSArray *annotationsArray = [arboDict objectForKey:@"annotations"];
CLLocationCoordinate2D workingCoordinate;
//loop through annotations array, creating parking annotations filled with the information found in the plist
for(NSDictionary *annotationContainerDict in annotationsArray){
ArboretumAnnotation *arboAnnot = [[ArboretumAnnotation alloc] init];
workingCoordinate.latitude = [[annotationContainerDict objectForKey:@"latitude"] doubleValue];
workingCoordinate.longitude = [[annotationContainerDict objectForKey:@"longitude"] doubleValue];
[arboAnnot setCoordinate:workingCoordinate];
[arboAnnot setTitle:[annotationContainerDict objectForKey:@"title"]];
[arboAnnot setSubtitle:[annotationContainerDict objectForKey:@"subtitle"]];
[arboAnnotations addObject:arboAnnot];
[arboAnnot release];
}//for
}//for
[mapView addAnnotations:arboAnnotations];
[arboAnnotations release];
}
//...
- (ArboretumAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id <MKAnnotation>)annotation
{
if ([annotation isKindOfClass:MKUserLocation.class]) {
//it's the built-in user location annotation(blue dot)
return nil;
}
NSString *annotIdentifier = @"annotation";
MKPinAnnotationView *recycledAnnotationView = (MKPinAnnotationView *)[self.mapView dequeueReusableAnnotationViewWithIdentifier:annotIdentifier];
if (!recycledAnnotationView) {
MKPinAnnotationView* customPinView = [[[MKPinAnnotationView alloc]
initWithAnnotation:annotation reuseIdentifier:annotIdentifier] autorelease];
UIImage *iconImage = [UIImage imageNamed:@"arboretum.png"];
CGRect resizeRect;
resizeRect.size = iconImage.size;
CGSize maxSize = CGRectInset(self.view.bounds,
10.0f,
10.0f).size;
maxSize.height -= self.navigationController.navigationBar.frame.size.height + 40.0f;
if (resizeRect.size.width > maxSize.width)
resizeRect.size = CGSizeMake(maxSize.width, resizeRect.size.height / resizeRect.size.width * maxSize.width);
if (resizeRect.size.height > maxSize.height)
resizeRect.size = CGSizeMake(resizeRect.size.width / resizeRect.size.height * maxSize.height, maxSize.height);
customPinView.image = iconImage;
//customPinView.image.frame = CGRectMake(kBorder, kBorder, kWidth - 2 * kBorder, kWidth - 2 * kBorder);
customPinView.opaque = NO;
//customPinView.pinColor = MKPinAnnotationColorPurple;
customPinView.canShowCallout = YES;
//display a disclosure icon on the right side of each annotation's callout
UIButton* rightButton = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];
customPinView.rightCalloutAccessoryView = rightButton;
return customPinView;
} else {
recycledAnnotationView.annotation = annotation;
}
return recycledAnnotationView;
}
- (void)didReceiveMemoryWarning {
// Releases the view if it doesn't have a superview.
[super didReceiveMemoryWarning];
// Release any cached data, images, etc that aren't in use.
}
- (void)viewDidUnload {
[super viewDidUnload];
// Release any retained subviews of the main view.
// e.g. self.myOutlet = nil;
}
- (void)dealloc {
[super dealloc];
}
@end
提前！
推荐答案
问题出在我如何检索坐标数据。我不经意地交换了经度与纬度，并且点不会在全球地图上的任何点显示。编译器没有发出警告或错误，所以它不被注意...所以，是的，我很尴尬，但这是你怎么学习，对吧？
Turns out the problem was in how I was retrieving coordinate data. I had swapped the longitude with the latitude inadvertently and the points wouldn't show at any point on the global map. No warnings or errors were issued by the compiler so it went unnoticed... So yeah, very embarrassing for me, but this is how you learn, right?
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