使用Google Maps SDK在地图上绘制错误的多段线

我正在尝试使用Google地图SDK在我的地图上绘制路线。 这是我调用的URL，我parsing的JSON响应的坐标数组：

id jsonResponse = [NSJSONSerialization JSONObjectWithData:responseObject options:NSJSONReadingMutableContainers error:nil]; int points_count = 0; points_count = [[[[[[jsonResponse objectForKey:@"routes"] objectAtIndex:0] objectForKey:@"legs"] objectAtIndex:0] objectForKey:@"steps"] count]; NSArray *steps = nil; if (points_count && [[[[jsonResponse objectForKey:@"routes"] objectAtIndex:0] objectForKey:@"legs"] count]) { steps = [[[[[jsonResponse objectForKey:@"routes"] objectAtIndex:0] objectForKey:@"legs"] objectAtIndex:0] objectForKey:@"steps"]; } NSMutableArray *coordinates = [[NSMutableArray alloc] initWithCapacity:points_count]; for (int i = 0; i < points_count; i++) { NSDictionary *start; NSDictionary *finish; double st_lat = [[[[steps objectAtIndex:i] objectForKey:@"start_location"] valueForKey:@"lat"] doubleValue]; double st_lon = [[[[steps objectAtIndex:i] objectForKey:@"start_location"] valueForKey:@"lng"] doubleValue]; if (st_lat > 0.0f && st_lon > 0.0f) { start = @{ @"latitude" : [NSNumber numberWithDouble:st_lat], @"longitude" : [NSNumber numberWithDouble:st_lon] }; } double end_lat = [[[[steps objectAtIndex:i] objectForKey:@"end_location"] valueForKey:@"lat"] doubleValue]; double end_lon = [[[[steps objectAtIndex:i] objectForKey:@"end_location"] valueForKey:@"lng"] doubleValue]; if (end_lat > 0.0f && end_lon > 0.0f) { finish = @{ @"latitude" : [NSNumber numberWithDouble:end_lat], @"longitude" : [NSNumber numberWithDouble:end_lon] }; } [coordinates addObject:@{ @"start" : start, @"finish" : finish }]; } 

而且比用这种方法绘制地图视图：

 GMSMutablePath *path = [GMSMutablePath path]; for (NSDictionary *d in directions) { NSDictionary *start = d[@"start"]; NSDictionary *finish = d[@"finish"]; CLLocationCoordinate2D c_start = CLLocationCoordinate2DMake([start[@"latitude"] doubleValue], [start[@"longitude"] doubleValue]); CLLocationCoordinate2D c_finish = CLLocationCoordinate2DMake([finish[@"latitude"] doubleValue], [finish[@"longitude"] doubleValue]); [path addCoordinate:c_start]; [path addCoordinate:c_finish]; } GMSPolyline *line = [GMSPolyline polylineWithPath:path]; line.strokeColor = [UIColor redColor]; line.strokeWidth = 2.0f; line.map = self.mapView; 

为什么它是这样画，而不是自己去街上？

我在这里做错了什么？

Answer 1

所以问题是，我用start_location和end_location而不是polyline – > points 。 修正了我的代码：

请求url，例如： https://maps.googleapis.com/maps/api/directions/json?origin=40.716072,-74.008836&destination=40.697545,-73.983892&sensor=false&waypoints=optimize:true&mode=driving : https://maps.googleapis.com/maps/api/directions/json?origin=40.716072,-74.008836&destination=40.697545,-73.983892&sensor=false&waypoints=optimize:true&mode=driving : https://maps.googleapis.com/maps/api/directions/json?origin=40.716072,-74.008836&destination=40.697545,-73.983892&sensor=false&waypoints=optimize:true&mode=driving

 id jsonResponse = [NSJSONSerialization JSONObjectWithData:responseObject options:NSJSONReadingMutableContainers error:nil]; int points_count = 0; points_count = [[[[[[jsonResponse objectForKey:@"routes"] objectAtIndex:0] objectForKey:@"legs"] objectAtIndex:0] objectForKey:@"steps"] count]; NSArray *steps = nil; if (points_count && [[[[jsonResponse objectForKey:@"routes"] objectAtIndex:0] objectForKey:@"legs"] count]) { steps = [[[[[jsonResponse objectForKey:@"routes"] objectAtIndex:0] objectForKey:@"legs"] objectAtIndex:0] objectForKey:@"steps"]; } NSMutableArray *coordinates = [[NSMutableArray alloc] initWithCapacity:points_count]; for (int i = 0; i < points_count; i++) { NSString *toDecode = [[[steps objectAtIndex:i] objectForKey:@"polyline"] valueForKey:@"points"]; NSArray *locations = [AppUtils decodePolylineWithString:toDecode]; for (int i = 0 ; i < locations.count ; i++) { if (i != locations.count - 1) { CLLocation *start = [locations objectAtIndex:i]; CLLocation *finish = [locations objectAtIndex:i + 1]; [coordinates addObject:@{ @"start" : start, @"finish" : finish }]; } } } GMSMutablePath *path = [GMSMutablePath path]; for (NSDictionary *d in directions) { CLLocation *start = d[@"start"]; CLLocation *finish = d[@"finish"]; [path addCoordinate:start.coordinate]; [path addCoordinate:finish.coordinate]; } GMSPolyline *line = [GMSPolyline polylineWithPath:path]; line.strokeColor = [UIColor redColor]; line.strokeWidth = 2.0f; line.map = self.mapView; + (NSArray*)decodePolylineWithString:(NSString *)encodedString { NSMutableArray *coordinates = [NSMutableArray array]; const char *bytes = [encodedString UTF8String]; NSUInteger length = [encodedString lengthOfBytesUsingEncoding:NSUTF8StringEncoding]; NSUInteger idx = 0; NSUInteger count = length / 4; CLLocationCoordinate2D *coords = calloc(count, sizeof(CLLocationCoordinate2D)); NSUInteger coordIdx = 0; float latitude = 0; float longitude = 0; while (idx < length) { char byte = 0; int res = 0; char shift = 0; do { byte = bytes[idx++] - 63; res |= (byte & 0x1F) << shift; shift += 5; } while (byte >= 0x20); float deltaLat = ((res & 1) ? ~(res >> 1) : (res >> 1)); latitude += deltaLat; shift = 0; res = 0; do { byte = bytes[idx++] - 0x3F; res |= (byte & 0x1F) << shift; shift += 5; } while (byte >= 0x20); float deltaLon = ((res & 1) ? ~(res >> 1) : (res >> 1)); longitude += deltaLon; float finalLat = latitude * 1E-5; float finalLon = longitude * 1E-5; CLLocationCoordinate2D coord = CLLocationCoordinate2DMake(finalLat, finalLon); coords[coordIdx++] = coord; CLLocation *location = [[CLLocation alloc] initWithLatitude:finalLat longitude:finalLon]; [coordinates addObject:location]; if (coordIdx == count) { NSUInteger newCount = count + 10; coords = realloc(coords, newCount * sizeof(CLLocationCoordinate2D)); count = newCount; } } free(coords); return coordinates; } 

我知道这有点肮脏，但是这是工作，它很好。

请享用。

Answer 2

试试这个绘制像驾驶模式的确切path – StreetMode，这是我的代码：

iOS GSMPolyLine