如何知道谷歌地圖上兩個位置之間的每個路線位置iOS sdk

Question

我正在使用​​獲取方向。通過此LINK幫助我繪製兩點之間的路線。現在我無法給出路線指令（例如：向左轉，轉向正確）給最終用戶。如何解決這個問題請幫助me.Now我使用下面的代碼

//Request the url 
-(void)getWayPoints:(CLLocationCoordinate2D)origin destinationIS:(CLLocationCoordinate2D)desti{ 

NSString *oLat = [NSString stringWithFormat:@"%f",origin.latitude]; 
NSString *oLong = [NSString stringWithFormat:@"%f",origin.longitude]; 

NSString *dLat = [NSString stringWithFormat:@"%f",desti.latitude]; 
NSString *dLong = [NSString stringWithFormat:@"%f",desti.longitude]; 

NSString *url = [NSString stringWithFormat:@"http://maps.googleapis.com/maps/api/directions/json?&origin=%@,%@&destination=%@,%@&sensor=false",oLat,oLong,dLat,dLong]; 
NSLog(@"url : %@", url); 
CLLocationCoordinate2D position = CLLocationCoordinate2DMake(
                  origin.latitude, 
                  origin.longitude); 
GMSMarker *marker = [GMSMarker markerWithPosition:position]; 
marker.map = mapView_; 

CLLocationCoordinate2D position1 = CLLocationCoordinate2DMake(
                  desti.latitude, 
                  desti.longitude); 
GMSMarker *marker1 = [GMSMarker markerWithPosition:position1]; 
marker1.map = mapView_; 

NSURL *googleRequestURL=[NSURL URLWithString:url]; 
NSLog(@"googleRequestURL : %@", googleRequestURL); 

dispatch_async(kBgQueue, ^{ 
    NSData* data = [NSData dataWithContentsOfURL: googleRequestURL]; 
    [self performSelectorOnMainThread:@selector(fetchedData:) withObject:data waitUntilDone:YES]; 
}); 



//Response from URL 

- (void)fetchedData:(NSData *)responseData { 
//parse out the json data 
NSError* error; 
// NSLog(@"responseData Data: %@", responseData); 
NSDictionary* json = [NSJSONSerialization 
         JSONObjectWithData:responseData 

         options:kNilOptions 
         error:&error]; 
NSArray* places = [json objectForKey:@"routes"]; 

NSDictionary *routes = [json objectForKey:@"routes"][0]; 

NSDictionary *route = [routes objectForKey:@"overview_polyline"]; 

NSArray *routes1 = [json objectForKey:@"routes"]; 
NSArray *legs = [routes1[0] objectForKey:@"legs"]; 
NSLog(@"legs %@", legs); 
NSArray *steps = [legs[0] objectForKey:@"steps"]; 

NSString *overview_route = [route objectForKey:@"points"]; 
GMSPath *path = [GMSPath pathFromEncodedPath:overview_route]; 
GMSPolyline *polyline = [GMSPolyline polylineWithPath:path]; 
polyline.strokeColor = [UIColor redColor]; 
polyline.strokeWidth = 5.f; 
polyline.map = mapView_; 

}

Answer 1

NSString *str=[NSString stringWithFormat:@"http://maps.googleapis.com/maps/api/directions/json?origin=%@&destination=%@&sensor=false",self.txtFrom.text,self.txtTo.text]; 

NSURL *url=[[NSURL alloc]initWithString:[str stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]]; 

NSURLRequest *request = [NSURLRequest requestWithURL:url cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:60.0]; 

NSData *data = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil]; 


NSError* error; 

NSDictionary* json = [NSJSONSerialization JSONObjectWithData:data options:kNilOptions error:&error]; 

NSArray* latestLoans = [json objectForKey:@"routes"]; 

NSMutableDictionary *legs=[[[latestLoans objectAtIndex:0] objectForKey:@"legs"] objectAtIndex:0]; 

NSString *startLocation,*endLocation,*totalDistance,*totalDuration; 

CLLocationCoordinate2D startLoc,endLoc; 

startLocation = [legs objectForKey:@"start_address"]; 

endLocation = [legs objectForKey:@"end_address"]; 

totalDistance = [[legs objectForKey:@"distance"] objectForKey:@"text"]; 

totalDuration = [[legs objectForKey:@"duration"] objectForKey:@"text"]; 

startLoc=CLLocationCoordinate2DMake([[[legs objectForKey:@"start_location"] objectForKey:@"lat"] doubleValue], [[[legs objectForKey:@"start_location"] objectForKey:@"lng"] doubleValue]); 

endLoc=CLLocationCoordinate2DMake([[[legs objectForKey:@"end_location"] objectForKey:@"lat"] doubleValue], [[[legs objectForKey:@"end_location"] objectForKey:@"lng"] doubleValue]); 


NSArray *steps=[legs objectForKey:@"steps"]; 

NSMutableDictionary *tempDict; 

if ([steps count]!=0) { 


    MKMapPoint* pointArr = malloc(sizeof(CLLocationCoordinate2D) * [steps count]+2); 

    [tv setText:@""]; 

    for(int idx = 0; idx < [steps count]+2; idx++) 
    { 

     CLLocationCoordinate2D workingCoordinate; 

     if (idx==0) { 

      workingCoordinate=startLoc; 

      MKMapPoint point = MKMapPointForCoordinate(workingCoordinate); 

      pointArr[idx] = point; 

      [tv setText:[NSString stringWithFormat:@"%@ %@",tv.text,@"START"]]; 

     } 

     else if (idx==[steps count]+1){ 

      workingCoordinate=endLoc; 

      MKMapPoint point = MKMapPointForCoordinate(workingCoordinate); 

      pointArr[idx+1] = point; 

      [tv setText:[NSString stringWithFormat:@"%@ %@",tv.text,@"\nEND"]]; 

     } 

     else{ 

      MKPolyline *pol= [self polylineWithEncodedString:[[[steps objectAtIndex:idx-1] objectForKey:@"polyline"] objectForKey:@"points"]]; 

      MKMapPoint point = *(pol.points); 

      pointArr[idx] = point; 

      [tv setText:[NSString stringWithFormat:@"%@\n\n%@",tv.text,[self flattenHTML:[[steps objectAtIndex:idx-1] objectForKey:@"html_instructions"]]]]; 

     } 


     tempDict = nil; 
    } 

    // create the polyline based on the array of points. 
    [mapView removeOverlay:routeLine]; 

    routeLine = [MKPolyline polylineWithPoints:pointArr count:[steps count]]; 

    [mapView addOverlay:routeLine]; 

    free(pointArr); 
} 

與以下支持的方法：？

-(NSArray*) calculateRoutesFrom:(NSString *) f to: (NSString ) t { NSString apiUrlStr = [NSString stringWithFormat:@" http://maps.google.com/maps?output=dragdir&saddr=%@&daddr=%@ ", f, t];

NSURL* apiUrl = [NSURL URLWithString:apiUrlStr]; NSLog(@"api url: %@", apiUrl);
NSString *apiResponse = [NSString stringWithContentsOfURL:apiUrl encoding:NSUTF8StringEncoding error:nil]; @try {

// TODO: better parsing. Regular expression? 

    NSInteger a = [apiResponse indexOf:@"points:\"" from:0]; 
    NSInteger b = [apiResponse indexOf:@"\",levels:\"" from:a] - 10; 

    NSInteger c = [apiResponse indexOf:@"tooltipHtml:\"" from:0]; 
    NSInteger d = [apiResponse indexOf:@"(" from:c]; 
    NSInteger e = [apiResponse indexOf:@")\"" from:d] - 2; 

    NSString* info = [[apiResponse substringFrom:d to:e] stringByReplacingOccurrencesOfString:@"\\x26#160;" withString:@""]; 
    NSLog(@"tooltip %@", info); 

    NSString* encodedPoints = [apiResponse substringFrom:a to:b]; 

    return [self decodePolyLine:[encodedPoints mutableCopy]]; 

} 
@catch (NSException * e) { 
    // TODO: show error 
}  

}