双击缩放时注释视图消失的问题

Question

我在 iPhone 上的 MapKit 中遇到了注释视图问题。我设法在地图上绘制自定义注释视图 - 没问题。我什至设法在拖动或缩放后重新绘制它们。但是，在某些情况下重绘不起作用：例如双击缩放。

我附加了一些代码，在地图上的特定位置绘制了一些矩形，当我使用两根手指手势进行缩放时，一切正常（即重新绘制矩形）。但是，当我双击时，矩形就会消失。更奇怪的是，所有方法都按其应有的顺序调用，最后，甚至调用了drawRect - 但没有绘制矩形。

所以这里是代码，请自己尝试 - 两根手指缩放有效，但双击缩放不起作用：

PlaygroundViewController.h

#import <UIKit/UIKit.h>
#import <MapKit/MapKit.h>

@interface PlaygroundViewController : UIViewController <MKMapViewDelegate>{
 MKMapView *mapView_;
 NSMutableDictionary* myViews_;
}

@end

PlaygroundViewController.m

#import "PlaygroundViewController.h"
#import "Territory.h"
#import "TerritoryView.h"

@implementation PlaygroundViewController

- (void)viewDidLoad {
    [super viewDidLoad];
 mapView_=[[MKMapView alloc] initWithFrame:self.view.bounds];
 [self.view insertSubview:mapView_ atIndex:0];
 mapView_.delegate = self;
 [mapView_ setMapType:MKMapTypeStandard];
    [mapView_ setZoomEnabled:YES];
    [mapView_ setScrollEnabled:YES];
 myViews_ = [[NSMutableDictionary alloc] init];
 for (int i = 0; i < 10; i++ ) {
  Territory *territory;
  territory = [[[Territory alloc] init] autorelease];
     territory.latitude_ = 40 + i;
  territory.longitude_ = -122 + i;
  [mapView_ addAnnotation:territory];

 }
}

- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id <MKAnnotation>)annotation {
 MKAnnotationView* territoryView = (MKAnnotationView*)[mapView dequeueReusableAnnotationViewWithIdentifier:@"Territory"];
 if (!territoryView){
  territoryView = [[[TerritoryView alloc] initWithAnnotation:annotation reuseIdentifier:@"Territory"] autorelease];
  Territory* currentTerritory = (Territory*) annotation;
  [myViews_ setObject:territoryView forKey:currentTerritory.territoryID_];
 }  
    else{
  territoryView.annotation = annotation;
 }  
 return territoryView; 
}

- (void)mapView:(MKMapView *)mapView regionDidChangeAnimated:(BOOL)animated {
 for (NSObject* key in [myViews_ allKeys]) {
  TerritoryView* territoryView = [myViews_ objectForKey:key];
  [territoryView initRedraw];
 }
}

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

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

Territory.h

#import <Foundation/Foundation.h>
#import <MapKit/MapKit.h>


@interface Territory : NSObject <MKAnnotation> {
 float latitude_;
 float longitude_;
 NSString* territoryID_;
}

@property (nonatomic) float latitude_;
@property (nonatomic) float longitude_;
@property (nonatomic, retain) NSString* territoryID_;


@end

Territory.m

#import "Territory.h"

@implementation Territory

@synthesize latitude_;
@synthesize longitude_;
@synthesize territoryID_;


- (CLLocationCoordinate2D)coordinate {
 CLLocationCoordinate2D coord_ = {self.latitude_, self.longitude_};
 return coord_;
}

-(id) init {
 if (self = [super init]) {
  self.territoryID_ = [NSString stringWithFormat:@"%p", self];
 }
 return self;
}


@end

TerritoryView.h

#import <Foundation/Foundation.h>
#import <MapKit/MapKit.h>

@interface TerritoryView : MKAnnotationView {

}

- (id)initWithAnnotation:(id <MKAnnotation>)annotation reuseIdentifier:(NSString *)reuseIdentifier;
- (void)initRedraw;

@end

TerritoryView.m

#import "TerritoryView.h"

@implementation TerritoryView

- (id)initWithAnnotation:(id <MKAnnotation>)annotation reuseIdentifier:(NSString *)reuseIdentifier {
    if ([super initWithAnnotation:annotation reuseIdentifier:@"Territory"]) {
  self.initRedraw;
    }
    return self;
}

- (void)initRedraw {
 self.frame = CGRectMake(0,0,40,40);
 [self setNeedsDisplay];
}

- (void)drawRect:(CGRect)rect {
 NSLog(@"in draw rect");
}

@end

任何帮助表示赞赏。这是压缩的项目：链接

Answer 1

请记住，框架的原点位于其父级的坐标系中，因此将其设置为零可能会将其移出屏幕。我怀疑它之所以能发挥作用，是因为在大多数情况下它会在你背后重置，但在失败的情况下却不会。

代替：
self.frame = CGRectMake(0,0,40,40);

和：
self.frame = CGRectMake(self.frame.origin.x,self.frame.origin.y,40,40);