iphone - iOS：MapKit：如何设置搜索请求获取的注释数量

Question

我有以下代码用于在我的应用程序中检索餐馆

NSLog(@"getting restaurants");
MKLocalSearchRequest *request = [[MKLocalSearchRequest alloc] init];
request.naturalLanguageQuery = @"restaurant";
request.region = self.mapView.region;

MKLocalSearch *localSearch = [[MKLocalSearch alloc] initWithRequest:request];
[localSearch startWithCompletionHandler:^(MKLocalSearchResponse *response, NSError *error) {

    NSMutableArray *annotations = [NSMutableArray array];

    [response.mapItems enumerateObjectsUsingBlock:^(MKMapItem *item, NSUInteger idx, BOOL *stop) {
        MapViewAnnotation *annotation = [[MapViewAnnotation alloc] initWithPlacemark:item.placemark];

        annotation.title = item.name;
        annotation.coordinate = item.placemark.location.coordinate;
        //annotation.subtitle = item.placemark.addressDictionary[kABPersonAddressStreetKey];
        //annotation.phone = item.phoneNumber;

        [annotations addObject:annotation];
    }];

    [self.mapView addAnnotations:annotations];
}];

如何设置要加载多少注释的限制？现在，只有少数可用点被加载。当我进一步放大时，我再次调用代码，并出现其他点。