Mapkit多点显示不同的图像

Question

我认为这应该很容易弄清楚...... 我有一个工作地图视图，它将一系列编号的图钉标记放到地图上。我从 plist 中调用引脚的图像，但是，当引脚掉落时，它们的编号都与最后一个引脚的编号相同。 （而不是 1,2,3..）

有问题的代码在下面，我只是不知道如何修复它......谢谢。

 NSString *path = [[NSBundle mainBundle] pathForResource:[route objectForKey:NAME_KEY] ofType:@"plist"];
 NSMutableArray* array = [[NSMutableArray alloc] initWithContentsOfFile:path];
 points = array;

 for (NSDictionary *routeDict in points){
 AllAnnotations *Annotation = [[AllAnnotations alloc] initWithDictionary:routeDict];
 [mapView addAnnotation:Annotation];
 [Annotation release];
 }



  for (NSDictionary *routeDict in points){ 
  NSString *first = [routeDict objectForKey: POINT_KEY];
  NSString *getNum = [routeDict objectForKey: COLOR_KEY];
  NSString *again = [getNum stringByAppendingString:first];
  NSString *imgValue = [again stringByAppendingString:@".png"];
  annotationView.image = [UIImage imageNamed:imgValue];
  }

  annotationView.canShowCallout = YES;

AllAnnotations.m
------------------------------------------------------------------------------------------
- (id) initWithDictionary:(NSDictionary *) dict
{
    self = [super init];
    if (self != nil) {
        coordinate.latitude = [[dict objectForKey:@"latitude"] doubleValue];
        coordinate.longitude = [[dict objectForKey:@"longitude"] doubleValue];
        self.title = [dict objectForKey:@"name"];
        self.subtitle = [dict objectForKey:@"subname"];

    }
    return self;
}

Answer 1

第二个循环遍历所有点（注释），当前注释视图以最后一个点的图像结束。该annotationView对象在该循环内没有改变。

我假设第二个循环和最后一行位于 viewForAnnotation 方法中。

您应该仅从当前注释对象获取routeDict并设置annotationView的图像一次，而不是循环遍历所有点。

假设您已将 routeDict 添加为 AllAnnotations 类中的属性，您将执行以下操作：

NSDictionary *routeDict = ((AllAnnotations *)annotation).routeDict;
NSString *first = [routeDict objectForKey: POINT_KEY];
NSString *getNum = [routeDict objectForKey: COLOR_KEY];
NSString *again = [getNum stringByAppendingString:first];
NSString *imgValue = [again stringByAppendingString:@".png"];
annotationView.image = [UIImage imageNamed:imgValue];

---

Edit:
Based on the updated code in your question and comments, here are the changes you need to make.

在 AllAnnotations.h 中，添加 ivar 来存储注释的图像文件名：

@interface AllAnnotations : NSObject <MKAnnotation> {
    //existing ivars here
    NSString *imageFileName;
}
//existing properties here
@property (copy) NSString *imageFileName;
//existing method headers here
@end

在 AllAnnotations.m 中，添加新 ivar 的合成并更新 initWithDictionary 和 dealloc 方法：

@synthesize imageFileName;

- (id) initWithDictionary:(NSDictionary *) dict
{
    self = [super init];
    if (self != nil) {
        coordinate.latitude = [[dict objectForKey:@"latitude"] doubleValue];
        coordinate.longitude = [[dict objectForKey:@"longitude"] doubleValue];
        self.title = [dict objectForKey:@"name"];
        self.subtitle = [dict objectForKey:@"subname"];

        //set this annotation's image file name...
        NSString *first = [dict objectForKey: POINT_KEY];
        NSString *getNum = [dict objectForKey: COLOR_KEY];
        NSString *again = [getNum stringByAppendingString:first];
        self.imageFileName = [again stringByAppendingString:@".png"];
    }
    return self;
}

- (void) dealloc
{
    [title release];
    [subtitle release];
    [imageFileName release];
    [super dealloc];
}

或者，您可以存储 POINT_KEY 和 COLOR_KEY 的值注释中的对象并在 viewForAnnotation 方法中生成文件名。

顺便说一句，“AllAnnotations”对于代表单个注释的此类来说并不是一个好名字。也许“RouteAnnotation”会更好。

最后，viewForAnnotation 方法应如下所示：

- (MKAnnotationView *) mapView:(MKMapView *)mapView viewForAnnotation:(id <MKAnnotation>)annotation
{
    MKAnnotationView * annotationView = (MKAnnotationView *)[mapView dequeueReusableAnnotationViewWithIdentifier:@"annot"];
    if (!annotationView) {
        annotationView = [[[MKAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:@"annot"] autorelease];
        annotationView.canShowCallout = YES;
    }
    else {
        annotationView.annotation = annotation;
    }

    AllAnnotations *routeAnnotation = (AllAnnotations *)annotation;
    annotationView.image = [UIImage imageNamed:routeAnnotation.imageFileName];

    return annotationView;
}