Question

我在iPhone上的MapKit中遇到了注释视图的问题。我设法在地图上绘制自定义注释视图 - 没有问题。我甚至设法在拖动或缩放后重绘它们。但是，有些情况下重绘不起作用：一个例子是双击缩放。

我附加了一些代码，我在地图上的特定位置绘制了几个矩形，当我使用双指手势缩放时，一切正常（即重新绘制矩形）。但是，当我双击时，矩形消失。更奇怪的是，所有方法都按照它们应该的顺序调用，最后甚至调用drawRect - 但是不绘制矩形。

所以这是代码，请自己尝试 - 两个手指缩放工作，但双击缩放不会：

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

感谢任何帮助。这是压缩项目：link

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置于屏幕外。我怀疑它之所以能够起作用的原因是它在大多数情况下会在你的背后重置，而不是在那些它失败的地方。

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

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

双击缩放时，注释视图的问题消失

1 个答案: