Question

我正在使用rest api从使用谷歌地图获取给定位置的地点列表但我遇到了一些问题。

主要问题：虽然大多数时候回复都是正常的，但有时我会得到格式错误的json或状态=＆＃34; Not Ok＆＃34;导致我的应用崩溃：

有没有办法测试状态＆amp;反序列化之前json的有效性，以防止崩溃或其他方式？

System.NullReferenceException: Object reference not set to an instance of an object.

从这一行：

place = JsonConvert.DeserializeObject<Places>(content,settings);

次要问题：我不确定处理返回的网页令牌的最佳方式是什么，以及如何将其用于重复查询

获取json的代码（try-catch什么都不做 - 应用程序仍然崩溃）

public async Task<Places> recurNearbyPlacesRequest(int radius , string pageToken)
        {
            HttpClient client = new HttpClient();

            Places place = null;

            string testurl = "https://maps.googleapis.com/maps/api/place/nearbysearch/json?location=45.498358,-73.4721847&radius=2000&pagetoken={0}&key={1}";

            var uri = new Uri(string.Format(testurl, pageToken , Constants.google_maps_key));

            var settings = new JsonSerializerSettings
            {
                NullValueHandling = NullValueHandling.Ignore,
                MissingMemberHandling = MissingMemberHandling.Ignore
            };

            try
            {
                var response = await client.GetAsync(uri);


                if (response.IsSuccessStatusCode)
                {
                    var content = await response.Content.ReadAsStringAsync();


                    place = JsonConvert.DeserializeObject<Places>(content,settings);

                }
            }
            catch (Exception E) { }


            return place;

        }

导致崩溃的错误Json：

{
   "error_message" : "The provided API key is invalid.",
   "html_attributions" : [],
   "results" : [],
   "status" : "REQUEST_DENIED"
}


{
   "html_attributions" : [],
   "results" : [],
   "status" : "INVALID_REQUEST"
}

地方类：

//JsontoC#

public class Location
{
    public double lat { get; set; }
    public double lng { get; set; }
}

public class Northeast
{
    public double lat { get; set; }
    public double lng { get; set; }
}

public class Southwest
{
    public double lat { get; set; }
    public double lng { get; set; }
}

public class Viewport
{
    public Northeast northeast { get; set; }
    public Southwest southwest { get; set; }
}

public class Geometry
{
    public Location location { get; set; }
    public Viewport viewport { get; set; }
}

public class OpeningHours
{
    public bool open_now { get; set; }
    public List<object> weekday_text { get; set; }
}

public class Photo
{
    public int height { get; set; }
    public List<string> html_attributions { get; set; }
    public string photo_reference { get; set; }
    public int width { get; set; }
}

public class Result
{
    public Geometry geometry { get; set; }
    public string icon { get; set; }
    public string id { get; set; }
    public string name { get; set; }
    public OpeningHours opening_hours { get; set; }
    public List<Photo> photos { get; set; }
    public string place_id { get; set; }
    public double rating { get; set; }
    public string reference { get; set; }
    public string scope { get; set; }
    public List<string> types { get; set; }
    public string vicinity { get; set; }
    public int? price_level { get; set; }
}

public class RootObject
{
    public List<object> html_attributions { get; set; }
    public string next_page_token { get; set; }
    public List<Result> results { get; set; }
    public string status { get; set; }
}

正确处理谷歌json请求和处理错误的方法

0 个答案: