MKAnnotationView viewForAnnotation从未调用 [英] MKAnnotationView viewForAnnotation never called

问题描述

我花了2天的时间查找错误，我必须在这里要求帮助。我有MapViewController，并在地图上放置一些引脚。我复制了MapCallouts的大部分代码和AppleMap代码示例的WeatherMap。

无论如何，我似乎删除或错过了重要的部分。似乎MapViewController和以下代码之间没有连接

   - （MKAnnotationView *）mapView：（MKMapView *）theMapView viewForAnnotation ：（id< MKAnnotation>）注释
 {
 NSLog（@MKAnnotationView）; 
 return nil; 
} 
  

设置注释看起来像这样，它的效果很好：

   - （void）createPoi：（CLLocationCoordinate2D）theCoordinate 
 {
 NSLog（@createPoi）; 
 
 RandomAnnotation * randomAnnotation = [[RandomAnnotation alloc] init]; 
 [randomAnnotation setTheCoordinate：theCoordinate]; 
 [randomAnnotation setTheTitle：@bla]; 
 [randomAnnotation setTheSubTitle：@bla]; 
 [self.mapAnnotations insertObject：randomAnnotation atIndex：kRandomAnnotationIndex]; 
 [randomAnnotation release]; 
 [self.mapView addAnnotation：[self.mapAnnotations objectAtIndex：kRandomAnnotationIndex]]; 
} 
  

我不知道出了什么问题。有人可以给我一个提示什么是什么吗？我不得不承认，我没有任何代表模式的经验。

解决方案

确保地图视图的委托属性设置。

如果地图在IB中创建，请右键单击并将其代理插座文件的所有者。

如果地图是以代码创建的，则在创建地图视图后设置委托：

  mapView.delegate = self; 
  

after i spend 2 days of searching the bug i have to ask for help here. i do have MapViewController and place some pins on the map. i´ve copied most of the code from MapCallouts and WeatherMap of the apple code samples.

anyhow it seems that i´ve deleted or missed essential parts. it seems there is no connection between the MapViewController and the following code

- (MKAnnotationView *)mapView:(MKMapView *)theMapView viewForAnnotation:(id <MKAnnotation>)annotation
{
    NSLog(@"MKAnnotationView");
    return nil;
}

setting an annotation looks like this and it works well:

- (void)createPoi:(CLLocationCoordinate2D)theCoordinate
{
    NSLog(@"createPoi");

    RandomAnnotation *randomAnnotation = [[RandomAnnotation alloc] init];
    [randomAnnotation setTheCoordinate:theCoordinate];
    [randomAnnotation setTheTitle:@"bla"];
    [randomAnnotation setTheSubTitle:@"bla"];
    [self.mapAnnotations insertObject:randomAnnotation atIndex:kRandomAnnotationIndex];
    [randomAnnotation release];
    [self.mapView addAnnotation:[self.mapAnnotations objectAtIndex:kRandomAnnotationIndex]];
}

i can´t figure out what's wrong. could anybody give me a hint what´s missing? i have to admit that i don´t have any experience with the delegate pattern.

解决方案

Make sure the map view's delegate property is set.

If the map is created in IB, right-click on it and hook up its delegate outlet to File's Owner.

If the map is created in code, set the delegate after creating the map view:

mapView.delegate = self;

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