爲什麼我無法從mapview中刪除我的註釋？

Question

爲什麼我無法從mapview中刪除我的註釋？

我的代碼：

• （無效）viewDidAppear：（BOOL）動畫{ [超級viewDidAppear：動畫]; [self becomeFirstResponder];

  NSMutableArray * annotations = [[NSMutableArray alloc] init]; NSString * path = [[NSBundle mainBundle] pathForResource：@「data」ofType：@「plist」]; NSDictionary * dict = [NSDictionary dictionaryWithContentsOfFile：path];如果（[[NSUserDefaults standardUserDefaults] boolForKey：@「blackKey」]） { NSLog（@「Black is on」）;

  NSArray * ann = [dict objectForKey：@「Category1」];

  的for（int i = 0;我< [安計數];我++）{

  NSString *coordinates = [[ann objectAtIndex:i] objectForKey:@"Coordinates"]; 
  
  double realLatitude = [[[coordinates componentsSeparatedByString:@","] objectAtIndex:1] doubleValue]; 
  double realLongitude = [[[coordinates componentsSeparatedByString:@","] objectAtIndex:0] doubleValue]; 
  
  MyAnnotation *myAnnotation = [[MyAnnotation alloc] init]; 
  CLLocationCoordinate2D theCoordinate; 
  theCoordinate.latitude = realLatitude; 
  theCoordinate.longitude = realLongitude; 
  
  myAnnotation.coordinate=CLLocationCoordinate2DMake(realLatitude,realLongitude); 
  
  myAnnotation.title = [[ann objectAtIndex:i] objectForKey:@"Name"]; 
  myAnnotation.subtitle = [[ann objectAtIndex:i] objectForKey:@"Address"]; 
  myAnnotation.icon = [[ann objectAtIndex:0] objectForKey:@"Icon"]; 
  
  if ([[NSUserDefaults standardUserDefaults] boolForKey:@"blackKey"]) 
  { 
      NSLog(@"Black is on"); 
      [mapView addAnnotation:myAnnotation]; 
      [annotations addObject:myAnnotation]; 
  
  } else 
      { 
       NSLog(@"Black is off"); 
  
       [self.mapView removeAnnotation:myAnnotation]; 
  
  
      } 
  
  } 
  

  }

  別的 { //什麼也不做 }

  } 
  

[self.mapView removeAnnotation:myAnnotation];對我不起作用

Answer 1

沒有什麼可以刪除的。您創建註釋，然後基於blackKey的檢查，您可以添加或刪除它。但是，當你刪除它時，你從未在此之前添加它。