Ios 基于文本动态获取地图位置

我在iOS中使用谷歌地图

我正在使用这段代码成功地静态地指向

-（void）指针位置 {

}

但是我想动态地设置文本（地址）

---

基于mapview上指向位置的文本（地址），我编写了自定义方法

- (CLLocationCoordinate2D) geoCodeUsingAddress:(NSString *)address
{

    double latitude = 0, longitude = 0;

    NSString *esc_addr =  [address  
                             stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];

    NSString *req = [NSString  

      stringWithFormat:@"http://maps.google.com/maps/api/geocode/json             
                                   sensor=false&address=%@", esc_addr];

    NSString *result = [NSString stringWithContentsOfURL:[NSURL URLWithString:req] 
                                         encoding:NSUTF8StringEncoding error:NULL];
    if (result) {

        NSScanner *scanner = [NSScanner scannerWithString:result];

        if ([scanner scanUpToString:@"\"lat\" :" intoString:nil] && 
            [scanner scanString:@"\"lat\" :" intoString:nil]) {

                   [scanner scanDouble:&latitude];

                   if ([scanner scanUpToString:@"\"lng\" :" intoString:nil] && 
                       [scanner scanString:@"\"lng\" :" intoString:nil]) {

                                 [scanner scanDouble:&longitude];
                   }
        }
    }
    CLLocationCoordinate2D center;
    center.latitude = latitude;
    center.longitude = longitude;

    return center;
}

输出：

当我传递字符串时，它会自动指向GoogleMap中所需的位置

- (CLLocationCoordinate2D) geoCodeUsingAddress:(NSString *)address
{

    double latitude = 0, longitude = 0;

    NSString *esc_addr =  [address  
                             stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];

    NSString *req = [NSString  

      stringWithFormat:@"http://maps.google.com/maps/api/geocode/json             
                                   sensor=false&address=%@", esc_addr];

    NSString *result = [NSString stringWithContentsOfURL:[NSURL URLWithString:req] 
                                         encoding:NSUTF8StringEncoding error:NULL];
    if (result) {

        NSScanner *scanner = [NSScanner scannerWithString:result];

        if ([scanner scanUpToString:@"\"lat\" :" intoString:nil] && 
            [scanner scanString:@"\"lat\" :" intoString:nil]) {

                   [scanner scanDouble:&latitude];

                   if ([scanner scanUpToString:@"\"lng\" :" intoString:nil] && 
                       [scanner scanString:@"\"lng\" :" intoString:nil]) {

                                 [scanner scanDouble:&longitude];
                   }
        }
    }
    CLLocationCoordinate2D center;
    center.latitude = latitude;
    center.longitude = longitude;

    return center;
}