Question

我使用以下代码获取特定地址的地理编码响应

    NSString *address = @"Doha,Qatar";
    NSLog(@"address : %@",address);
    NSString *esc_addr = [address stringByAddingPercentEscapesUsingEncoding: NSUTF8StringEncoding];
    NSString *req = [NSString stringWithFormat: @"http://www.maps.google.com/maps/api/geocode/json?address=%@&sensor=false", esc_addr];

    NSURL *url=[NSURL URLWithString:req];
    NSLog(@"url : %@",url);
    NSData *data=[NSData dataWithContentsOfURL:url];
    NSLog(@"data : %@",data);
    NSError *error=nil;
    id response=[NSJSONSerialization JSONObjectWithData:data options:
                 NSJSONReadingMutableContainers error:&error];

    NSLog(@"The JSON Object: %@ Or Error is: %@", response, error);

但是响应始终为空。

回应，

2014-11-27 16:35:48.961 MyProj[15279:254055] address : Doha,Qatar
2014-11-27 16:35:48.961 MyProj[15279:254055] url : http://www.maps.google.com/maps/api/geocode/json?address=Doha,Qatar&sensor=false
2014-11-27 16:35:49.005 MyProj[15279:254055] data : (null)
2014-11-27 16:35:49.008 MyProj[15279:254055] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'data parameter is nil'

但是当我在眉毛中打开URL时，它会将输出显示为

{
   "results" : [
      {
         "address_components" : [
            {
               "long_name" : "Doha",
               "short_name" : "Doha",
               "types" : [ "locality", "political" ]
            },
            {
               "long_name" : "Doha",
               "short_name" : "Doha",
               "types" : [ "administrative_area_level_1", "political" ]
            },
            {
               "long_name" : "Qatar",
               "short_name" : "QA",
               "types" : [ "country", "political" ]
            }
         ],
         "formatted_address" : "Doha, Qatar",
         "geometry" : {
            "bounds" : {
               "northeast" : {
                  "lat" : 25.4125783,
                  "lng" : 51.6281212
               },
               "southwest" : {
                  "lat" : 25.1954283,
                  "lng" : 51.4307964
               }
            },
            "location" : {
               "lat" : 25.286667,
               "lng" : 51.533333
            },
            "location_type" : "APPROXIMATE",
            "viewport" : {
               "northeast" : {
                  "lat" : 25.4125783,
                  "lng" : 51.6281212
               },
               "southwest" : {
                  "lat" : 25.1954283,
                  "lng" : 51.4307964
               }
            }
         },
         "types" : [ "locality", "political" ]
      }
   ],
   "status" : "OK"
}

空响应的原因是什么，

感谢您的任何建议。

Answer 1

我测试了你的代码，它运行正常。

数据参数不为null。它包含json的信息。

所以，也许你必须检查这些

Google Maps SDK的版本（我使用1.8.0.8950 - 不是最新的）
GMS服务的初始化
您的谷歌地图的API密钥。

Answer 2

感谢所有建议。 dataWithContentsOfURL:有时不适合我。所以我使用了NSURLConnection。现在它运作良好。

以下是我所做的更改。

    NSString *address = @"Doha,Qatar";
    NSLog(@"address : %@",address);
    NSString *esc_addr = [address stringByAddingPercentEscapesUsingEncoding: NSUTF8StringEncoding];
    NSString *req = [NSString stringWithFormat: @"http://www.maps.google.com/maps/api/geocode/json?address=%@&sensor=false", esc_addr];

    NSURL *url=[NSURL URLWithString:req];

    NSData *theData = [NSURLConnection sendSynchronousRequest:[NSURLRequest requestWithURL:url]
                                            returningResponse:nil
                                                        error:nil];

    NSDictionary *googleResponse = [NSJSONSerialization JSONObjectWithData:theData
                                                            options:0
                                                              error:nil];

map geocode API提供Null响应

2 个答案: