C# 使用JSON.NET windows phone解析JSON

我试图解析openweathermap中的7天预测。我在foreach（JsonRequest[“main”][“wind”][“name”][“weather”]）中的JObject数组的

行中捕捉到一个空引用exeption

，但我不明白为什么。我需要填好我的班级，并展示7天的预测

string queryString = "http://api.openweathermap.org/data/2.1/forecast/city?lat=" + latitude + "&lon=" + longitude + "?units=metric";
        dynamic results = await DataService.getDataFromService(queryString).ConfigureAwait(false);

        MyWeather wetherobject = new MyWeather();
        PanoramaItemObject ItemObject = new PanoramaItemObject();

        var JsonRequest = JObject.Parse(results);

        foreach (JObject array in JsonRequest["main"]["wind"]["name"]["weather"])
        {
            JObject obj = JObject.Parse(array.ToString());
            wetherobject.Temperature=(string)obj["temp"];
            wetherobject.Humidity=(string)obj["humidity"];
            wetherobject.Temperature_max=(string)obj["temp_max"];
            wetherobject.Temperature_min=(string)obj["temp_min"];
            wetherobject.Title=(string)obj["main"];
            wetherobject.Description=(string)obj["description"];
            wetherobject.Wind=(string)obj["speed"];
            ItemObject.forecasts.Add(wetherobject);
        }

层次结构如下：

    public class Coord
{
    public double lon { get; set; }
    public double lat { get; set; }
}

public class City
{
    public int id { get; set; }
    public string name { get; set; }
    public Coord coord { get; set; }
    public string country { get; set; }
    public int population { get; set; }
}

public class Main
{
    public double temp { get; set; }
    public double temp_min { get; set; }
    public double temp_max { get; set; }
    public double pressure { get; set; }
    public double sea_level { get; set; }
    public double grnd_level { get; set; }
    public int humidity { get; set; }
    public double temp_kf { get; set; }
}

public class Weather
{
    public int id { get; set; }
    public string main { get; set; }
    public string description { get; set; }
    public string icon { get; set; }
}

public class Clouds
{
    public int all { get; set; }
}

public class Wind
{
    public double speed { get; set; }
    public double deg { get; set; }
}

public class Sys
{
    public string pod { get; set; }
}

public class Rain
{
    public double __invalid_name__3h { get; set; }
}

public class List
{
    public int dt { get; set; }
    public Main main { get; set; }
    public List<Weather> weather { get; set; }
    public Clouds clouds { get; set; }
    public Wind wind { get; set; }
    public Sys sys { get; set; }
    public string dt_txt { get; set; }
    public Rain rain { get; set; }
}

public class RootObject
{
    public string cod { get; set; }
    public string message { get; set; }
    public City city { get; set; }
    public int cnt { get; set; }
    public string model { get; set; }
    public List<List> list { get; set; }
}

---

您的对象层次结构不同。下面的例子应该有用

double latitude = 51.5085300;
double longitude = -0.1257400;
string queryString = "http://api.openweathermap.org/data/2.1/forecast/city?lat=" + latitude + "&lon=" + longitude + "?units=metric";

HttpClient client = new HttpClient();
string results = await client.GetStringAsync(queryString).ConfigureAwait(false);

dynamic jobj = JObject.Parse(results);
foreach (var item in jobj.list)
{

    Console.WriteLine("{0} TEMP:{1} WIND:{2}", 
        DateTime.ParseExact((string)item.dt_txt, "yyyy-MM-dd HH:mm:ss", null), 
        (item.main.temp - 273.15), 
        item.wind.speed);
}

---

您的对象层次结构不像

main.wind.name.weather

。将json粘贴到并查看结果。（你也可以使用JsonViewer）同意EZI所说的。还可以尝试发布以可视化您的数据。顺便说一句，当查询一个长的属性序列时，一些中间属性可能会丢失，我建议使用，因为它将返回一个空的枚举，而不是抛出一个空引用异常。dynamic JsonRequest=JObject.Parse（results）；foreach（JsonRequest.list中的var数组）现在我得到错误“Newtonsoft.Json.Linq.JObject”不包含“list”的定义@Youhy我发布了一个测试过的工作代码。你能用wetherobject.Temperature作为输出而不是控制台来编写你的示例吗？我已经发布了我的新代码，我不明白出了什么问题

double latitude = 51.5085300;
double longitude = -0.1257400;
string queryString = "http://api.openweathermap.org/data/2.1/forecast/city?lat=" + latitude + "&lon=" + longitude + "?units=metric";

HttpClient client = new HttpClient();
string results = await client.GetStringAsync(queryString).ConfigureAwait(false);

dynamic jobj = JObject.Parse(results);
foreach (var item in jobj.list)
{

    Console.WriteLine("{0} TEMP:{1} WIND:{2}", 
        DateTime.ParseExact((string)item.dt_txt, "yyyy-MM-dd HH:mm:ss", null), 
        (item.main.temp - 273.15), 
        item.wind.speed);
}