Ich verwende MapKit api, um die aktuelle Position auf der Karte abzurufen und eine Route zwischen zwei Positionen zu zeichnen, auf die durch Stecknadeln hingewiesen wird. Außerdem möchte ich alle Hauptpositionen zwischen der Route anzeigen. Ich benutze die unten stehende Funktion, um eine Route zwischen zwei Orten zu erhalten

- (NSArray*)getRoutePointFrom:(MyLocation*)origin to:(MyLocation*)destination
{
 NSString* saddr = [NSString stringWithFormat:@"%f,%f", origin.coordinate.latitude, origin.coordinate.longitude];
 NSString* daddr = [NSString stringWithFormat:@"%f,%f", destination.coordinate.latitude, destination.coordinate.longitude];


 NSURL *url=[NSURL URLWithString:[NSString stringWithFormat:@"http://maps.googleapis.com/maps/api/directions/json?origin=%@&destination=%@&sensor=false&avoid=highways&mode=driving",saddr,daddr]];

 NSError *error=nil;

 NSMutableURLRequest *request = [[NSMutableURLRequest alloc] init] ;

 [request setURL:url];
 [request setHTTPMethod:@"POST"];

  NSURLResponse *response = nil;

  NSData *responseData = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error: &error];

  NSString *responseString = [[NSString alloc] initWithData:responseData encoding:NSUTF8StringEncoding];

 SBJsonParser *json=[[SBJsonParser alloc] init];

 NSDictionary *dic=[json objectWithString:responseString error:nil];

 NSDictionary *nextdic=[dic valueForKey:@"routes"];
 NSDictionary *legdic=[nextdic valueForKey:@"legs"];
 NSDictionary *stepdic=[legdic valueForKey:@"steps"];

 NSArray *array=[[NSArray alloc] initWithArray:[[stepdic valueForKey:@"polyline"] valueForKey:@"points"]];  


 NSString *string=[NSString stringWithFormat:@"%@",[[array objectAtIndex:0] objectAtIndex:0]];




 return [self decodePolyLine:[string mutableCopy]];

}



-(NSMutableArray *)decodePolyLine:(NSString *)encodedStr 
{  

 NSMutableString *encoded = [[NSMutableString alloc] initWithCapacity:[encodedStr length]];  
 [encoded appendString:encodedStr];  
 [encoded replaceOccurrencesOfString:@"\\\\" withString:@"\\"  
                             options:NSLiteralSearch  
                               range:NSMakeRange(0, [encoded length])];  
 NSInteger len = [encoded length];  

 NSInteger index = 0;  
 NSMutableArray *array = [[NSMutableArray alloc] init] ;  
 NSInteger lat=0;  
 NSInteger lng=0;  
 while (index < len) {  
  NSInteger b;  
  NSInteger shift = 0;  
  NSInteger result = 0;  
  do {  
   b = [encoded characterAtIndex:index++] - 63;  
   result |= (b & 0x1f) << shift;  
   shift += 5;  
  } while (b >= 0x20);  
  NSInteger dlat = ((result & 1) ? ~(result >> 1) : (result >> 1));  
  lat += dlat;  
  shift = 0;  
  result = 0;  
  do {  
   b = [encoded characterAtIndex:index++] - 63;  
   result |= (b & 0x1f) << shift;  
   shift += 5;  
  } while (b >= 0x20);  
  NSInteger dlng = ((result & 1) ? ~(result >> 1) : (result >> 1));  
  lng += dlng;  
  NSNumber *latitude = [[NSNumber alloc] initWithFloat:lat * 1e-5];  
  NSNumber *longitude = [[NSNumber alloc] initWithFloat:lng * 1e-5];  
  //          printf("[%f,", [latitude doubleValue]);  
  //          printf("%f]", [longitude doubleValue]);  
  CLLocation *loc =[[CLLocation alloc] initWithLatitude:[latitude floatValue] longitude:[longitude floatValue]] ;  
  [array addObject:loc];  
 }  

 NSLog(@"array in decode polygon is %@",array);

 return array;  
}

aber es funktioniert nicht. ..

hilfe dazu danke! ...