173 votos

Analizar JSON en C #

Estoy tratando de analizar algunos datos JSON a partir de la de Google AJAX Search API. Tengo esta URL y me gustaría romper hacia abajo de manera que los resultados se muestran. He actualmente se escribe este código, pero estoy bastante perdido en cuanto a qué hacer a continuación, aunque hay un número de ejemplos que hay con simplificado cadenas JSON.

Siendo nuevo en C# y .NET en general he luchado para conseguir una verdadera salida de texto para mi ASP.NET la página me ha recomendado dar JSON.NET un intento. Podría alguien me apunte en la dirección correcta para simplemente escribir algo de código que voy a tomar en JSON desde el Google AJAX Search API y imprimir a la pantalla?


EDIT: TODO ARREGLADO! Todos los resultados están trabajando bien. Gracias de nuevo Dreas Grech!

using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.ServiceModel.Web;
using System.Runtime.Serialization;
using System.Runtime.Serialization.Json;
using System.IO;
using System.Text;

public partial class _Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        GoogleSearchResults g1 = new GoogleSearchResults();
        const string json = @"{""responseData"": {""results"":[{""GsearchResultClass"":""GwebSearch"",""unescapedUrl"":""http://www.cheese.com/"",""url"":""http://www.cheese.com/"",""visibleUrl"":""www.cheese.com"",""cacheUrl"":""http://www.google.com/search?q\u003dcache:bkg1gwNt8u4J:www.cheese.com"",""title"":""\u003cb\u003eCHEESE\u003c/b\u003e.COM - All about \u003cb\u003echeese\u003c/b\u003e!."",""titleNoFormatting"":""CHEESE.COM - All about cheese!."",""content"":""\u003cb\u003eCheese\u003c/b\u003e - everything you want to know about it. Search \u003cb\u003echeese\u003c/b\u003e by name, by types   of milk, by textures and by countries.""},{""GsearchResultClass"":""GwebSearch"",""unescapedUrl"":""http://en.wikipedia.org/wiki/Cheese"",""url"":""http://en.wikipedia.org/wiki/Cheese"",""visibleUrl"":""en.wikipedia.org"",""cacheUrl"":""http://www.google.com/search?q\u003dcache:n9icdgMlCXIJ:en.wikipedia.org"",""title"":""\u003cb\u003eCheese\u003c/b\u003e - Wikipedia, the free encyclopedia"",""titleNoFormatting"":""Cheese - Wikipedia, the free encyclopedia"",""content"":""\u003cb\u003eCheese\u003c/b\u003e is a food consisting of proteins and fat from milk, usually the milk of   cows, buffalo, goats, or sheep. It is produced by coagulation of the milk \u003cb\u003e...\u003c/b\u003e""},{""GsearchResultClass"":""GwebSearch"",""unescapedUrl"":""http://www.ilovecheese.com/"",""url"":""http://www.ilovecheese.com/"",""visibleUrl"":""www.ilovecheese.com"",""cacheUrl"":""http://www.google.com/search?q\u003dcache:GBhRR8ytMhQJ:www.ilovecheese.com"",""title"":""I Love \u003cb\u003eCheese\u003c/b\u003e!, Homepage"",""titleNoFormatting"":""I Love Cheese!, Homepage"",""content"":""The American Dairy Association\u0026#39;s official site includes recipes and information   on nutrition and storage of \u003cb\u003echeese\u003c/b\u003e.""},{""GsearchResultClass"":""GwebSearch"",""unescapedUrl"":""http://www.gnome.org/projects/cheese/"",""url"":""http://www.gnome.org/projects/cheese/"",""visibleUrl"":""www.gnome.org"",""cacheUrl"":""http://www.google.com/search?q\u003dcache:jvfWnVcSFeQJ:www.gnome.org"",""title"":""\u003cb\u003eCheese\u003c/b\u003e"",""titleNoFormatting"":""Cheese"",""content"":""\u003cb\u003eCheese\u003c/b\u003e uses your webcam to take photos and videos, applies fancy special effects   and lets you share the fun with others. It was written as part of Google\u0026#39;s \u003cb\u003e...\u003c/b\u003e""}],""cursor"":{""pages"":[{""start"":""0"",""label"":1},{""start"":""4"",""label"":2},{""start"":""8"",""label"":3},{""start"":""12"",""label"":4},{""start"":""16"",""label"":5},{""start"":""20"",""label"":6},{""start"":""24"",""label"":7},{""start"":""28"",""label"":8}],""estimatedResultCount"":""14400000"",""currentPageIndex"":0,""moreResultsUrl"":""http://www.google.com/search?oe\u003dutf8\u0026ie\u003dutf8\u0026source\u003duds\u0026start\u003d0\u0026hl\u003den-GB\u0026q\u003dcheese""}}, ""responseDetails"": null, ""responseStatus"": 200}";
        g1 = JSONHelper.Deserialise<GoogleSearchResults>(json);
        Response.Write(g1.content);
    }
}

public class JSONHelper
{
    public static T Deserialise<T>(string json)
    {
        T obj = Activator.CreateInstance<T>();
        MemoryStream ms = new MemoryStream(Encoding.Unicode.GetBytes(json));
        DataContractJsonSerializer serialiser = new DataContractJsonSerializer(obj.GetType());
        ms.Close();
        return obj;
    }
}
/// Deserialise from JSON
[Serializable]
public class GoogleSearchResults
{
    public GoogleSearchResults() { }
    public GoogleSearchResults(string _unescapedUrl, string _url, string _visibleUrl, string _cacheUrl, string _title, string _titleNoFormatting, string _content)
    {
        this.unescapedUrl = _unescapedUrl;
        this.url = _url;
        this.visibleUrl = _visibleUrl;
        this.cacheUrl = _cacheUrl;
        this.title = _title;
        this.titleNoFormatting = _titleNoFormatting;
        this.content = _content;
    }

    string _unescapedUrl;
    string _url;
    string _visibleUrl;
    string _cacheUrl;
    string _title;
    string _titleNoFormatting;
    string _content;

    [DataMember]
    public string unescapedUrl
    {
        get { return _unescapedUrl; }
        set { _unescapedUrl = value; }
    }

    [DataMember]
    public string url
    {
        get { return _url; }
        set { _url = value; }
    }

    [DataMember]
    public string visibleUrl
    {
        get { return _visibleUrl; }
        set { _visibleUrl = value; }
    }
    [DataMember]
    public string cacheUrl
    {
        get { return _cacheUrl; }
        set { _cacheUrl = value; }
    }

    [DataMember]
    public string title
    {
        get { return _title; }
        set { _title = value; }
    }

    [DataMember]
    public string titleNoFormatting
    {
        get { return _titleNoFormatting; }
        set { _titleNoFormatting = value; }
    }

    [DataMember]
    public string content
    {
        get { return _content; }
        set { _content = value; }
    }
}

El código se compila y ejecuta a la perfección, pero no muestra ningún resultado. Podría alguien ayudarme con devolución de lo que requieren, los resultados listos para imprimir en la pantalla?

Edición:

Json.NET trabaja con la misma JSON y clases como el ejemplo de arriba.

GoogleSearchResults g1 = JsonConvert.DeserializeObject<GoogleSearchResults>(json);

Enlace: Serializar y Deserializar JSON con Json.NET

Relacionados

C# - análisis de datos con el formato json en anidadas tablas hash
Analizar matriz JSON

132voto

Andreas Grech Puntos 39188

[Actualización]
Me he dado cuenta de por qué no recibir los resultados de la espalda... usted tiene una línea que falta en su Deserialize método. Se fueron olvidando de asignar los resultados a su obj :

public static T Deserialise<T>(string json)
{
    T obj = Activator.CreateInstance<T>();
    using (MemoryStream ms = new MemoryStream(Encoding.Unicode.GetBytes(json)))
    {
        DataContractJsonSerializer serializer = new DataContractJsonSerializer(obj.GetType());
        obj = (T)serializer.ReadObject(ms); // <== Your missing line
        return obj;
    } 
}

También, sólo para referencia, aquí está la Serialize método :

public static string Serialize<T>(T obj)
{
    DataContractJsonSerializer serializer = new DataContractJsonSerializer(obj.GetType());
    using (MemoryStream ms = new MemoryStream())
    {
        serializer.WriteObject(ms, obj);
        return Encoding.Default.GetString(ms.ToArray());
    }
}

Editar

Si desea utilizar Json.NET aquí, son el equivalente a Serializar/Deserializar métodos para el código de arriba..

Deserializar:

JsonConvert.DeserializeObject<T>(string json);

Serializar:

JsonConvert.SerializeObject(object o);

Este ya son parte de Json.NET así que usted puede apenas llamar en el JsonConvert clase.

Enlace: Serializar y Deserializar JSON con Json.NET



Ahora, la razón por la que usted está consiguiendo un StackOverflow es debido a su Properties.

Tomemos por ejemplo esta :

[DataMember]
public string unescapedUrl
{
    get { return unescapedUrl; } // <= this line is causing a Stack Overflow
    set { this.unescapedUrl = value; }
}

Observe que en la getter, que devuelve el real de la propiedad (es decir, la propiedad de captador se llama a sí misma una y otra vez), y por lo tanto usted está creando una recursividad infinita.


Propiedades (2.0) debe ser definido como tal :

string _unescapedUrl; // <= private field

[DataMember]
public string unescapedUrl
{
    get { return _unescapedUrl; } 
    set { _unescapedUrl = value; }
}

Usted tiene un campo privado y, a continuación, devolver el valor de ese campo en el captador, y establecer el valor de ese campo en la incubadora.


Por cierto, si usted está utilizando el Framework 3.5, usted puede hacer esto y evitar los campos de copia de seguridad, y dejar que el compilador se encargará de que :

public string unescapedUrl { get; set;}

12voto

Joe Chung Puntos 6263

Su clase de datos no coincide con el objeto JSON. Utilice en su lugar:

 [DataContract]
public class GoogleSearchResults
{
    [DataMember]
    public ResponseData responseData { get; set; }
}

[DataContract]
public class ResponseData
{
    [DataMember]
    public IEnumerable<Results> results { get; set; }
}

[DataContract]
public class Results
{
    [DataMember]
    public string unescapedUrl { get; set; }

    [DataMember]
    public string url { get; set; }

    [DataMember]
    public string visibleUrl { get; set; }

    [DataMember]
    public string cacheUrl { get; set; }

    [DataMember]
    public string title { get; set; }

    [DataMember]
    public string titleNoFormatting { get; set; }

    [DataMember]
    public string content { get; set; }
}
 

Además, usted no tiene que crear una instancia de la clase para obtener su tipo para la deserialización:

 public static T Deserialise<T>(string json)
{
    using (var ms = new MemoryStream(Encoding.Unicode.GetBytes(json)))
    {
        var serialiser = new DataContractJsonSerializer(typeof(T));
        return (T)serialiser.ReadObject(ms);
    }
}
 

12voto

BrunoLM Puntos 26573

He encontrado este enfoque que analizar JSON en un objeto dinámico, que se extiende DynamicObject y JavascriptConverter para convertir la cadena en un objeto.

DynamicJsonObject

public class DynamicJsonObject : DynamicObject
{
    private IDictionary<string, object> Dictionary { get; set; }

    public DynamicJsonObject(IDictionary<string, object> dictionary)
    {
        this.Dictionary = dictionary;
    }

    public override bool TryGetMember(GetMemberBinder binder, out object result)
    {
        result = this.Dictionary[binder.Name];

        if (result is IDictionary<string, object>)
        {
            result = new DynamicJsonObject(result as IDictionary<string, object>);
        }
        else if (result is ArrayList && (result as ArrayList) is IDictionary<string, object>)
        {
            result = new List<DynamicJsonObject>((result as ArrayList).ToArray().Select(x => new DynamicJsonObject(x as IDictionary<string, object>)));
        }
        else if (result is ArrayList)
        {
            result = new List<object>((result as ArrayList).ToArray());
        }

        return this.Dictionary.ContainsKey(binder.Name);
    }
}

Convertidor

public class DynamicJsonConverter : JavaScriptConverter
{
    public override object Deserialize(IDictionary<string, object> dictionary, Type type, JavaScriptSerializer serializer)
    {
        if (dictionary == null)
            throw new ArgumentNullException("dictionary");

        if (type == typeof(object))
        {
            return new DynamicJsonObject(dictionary);
        }

        return null;
    }

    public override IDictionary<string, object> Serialize(object obj, JavaScriptSerializer serializer)
    {
        throw new NotImplementedException();
    }

    public override IEnumerable<Type> SupportedTypes
    {
        get { return new ReadOnlyCollection<Type>(new List<Type>(new Type[] { typeof(object) })); }
    }
}

Uso (ejemplo json):

JavaScriptSerializer jss = new JavaScriptSerializer();
jss.RegisterConverters(new JavaScriptConverter[] { new DynamicJsonConverter() });

dynamic glossaryEntry = jss.Deserialize(json, typeof(object)) as dynamic;

Console.WriteLine("glossaryEntry.glossary.title: " + glossaryEntry.glossary.title);
Console.WriteLine("glossaryEntry.glossary.GlossDiv.title: " + glossaryEntry.glossary.GlossDiv.title);
Console.WriteLine("glossaryEntry.glossary.GlossDiv.GlossList.GlossEntry.ID: " + glossaryEntry.glossary.GlossDiv.GlossList.GlossEntry.ID);
Console.WriteLine("glossaryEntry.glossary.GlossDiv.GlossList.GlossEntry.GlossDef.para: " + glossaryEntry.glossary.GlossDiv.GlossList.GlossEntry.GlossDef.para);
foreach (var also in glossaryEntry.glossary.GlossDiv.GlossList.GlossEntry.GlossDef.GlossSeeAlso)
{
    Console.WriteLine("glossaryEntry.glossary.GlossDiv.GlossList.GlossEntry.GlossDef.GlossSeeAlso: " + also);
}

Este método devolverá true, en caso contrario se producirá un error. Por ejemplo. se puede producir un error si una clave no existe.

Volviendo true y el vaciado result devolverá un valor vacío en lugar de tirar un error.

public override bool TryGetMember(GetMemberBinder binder, out object result)
{

    if (!this.Dictionary.ContainsKey(binder.Name))
    {
        result = "";
    }
    else
    {
        result = this.Dictionary[binder.Name];
    }

    if (result is IDictionary<string, object>)
    {
        result = new DynamicJsonObject(result as IDictionary<string, object>);
    }
    else if (result is ArrayList && (result as ArrayList) is IDictionary<string, object>)
    {
        result = new List<DynamicJsonObject>((result as ArrayList).ToArray().Select(x => new DynamicJsonObject(x as IDictionary<string, object>)));
    }
    else if (result is ArrayList)
    {
        result = new List<object>((result as ArrayList).ToArray());
    }

    return true; // this.Dictionary.ContainsKey(binder.Name);
}

7voto

mamezcua Puntos 41

Sólo pienso todo el ejemplo podría ser útil. Este es el ejemplo para este problema.

 using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.ServiceModel.Web;
using System.Runtime.Serialization;
using System.Runtime.Serialization.Json;
using System.IO;
using System.Text;
using System.Collections.Generic;

public partial class _Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        GoogleSearchResults g1 = new GoogleSearchResults();
        const string json = @"{""responseData"": {""results"":[{""GsearchResultClass"":""GwebSearch"",""unescapedUrl"":""http://www.cheese.com/"",""url"":""http://www.cheese.com/"",""visibleUrl"":""www.cheese.com"",""cacheUrl"":""http://www.google.com/search?q\u003dcache:bkg1gwNt8u4J:www.cheese.com"",""title"":""\u003cb\u003eCHEESE\u003c/b\u003e.COM - All about \u003cb\u003echeese\u003c/b\u003e!."",""titleNoFormatting"":""CHEESE.COM - All about cheese!."",""content"":""\u003cb\u003eCheese\u003c/b\u003e - everything you want to know about it. Search \u003cb\u003echeese\u003c/b\u003e by name, by types   of milk, by textures and by countries.""},{""GsearchResultClass"":""GwebSearch"",""unescapedUrl"":""http://en.wikipedia.org/wiki/Cheese"",""url"":""http://en.wikipedia.org/wiki/Cheese"",""visibleUrl"":""en.wikipedia.org"",""cacheUrl"":""http://www.google.com/search?q\u003dcache:n9icdgMlCXIJ:en.wikipedia.org"",""title"":""\u003cb\u003eCheese\u003c/b\u003e - Wikipedia, the free encyclopedia"",""titleNoFormatting"":""Cheese - Wikipedia, the free encyclopedia"",""content"":""\u003cb\u003eCheese\u003c/b\u003e is a food consisting of proteins and fat from milk, usually the milk of   cows, buffalo, goats, or sheep. It is produced by coagulation of the milk \u003cb\u003e...\u003c/b\u003e""},{""GsearchResultClass"":""GwebSearch"",""unescapedUrl"":""http://www.ilovecheese.com/"",""url"":""http://www.ilovecheese.com/"",""visibleUrl"":""www.ilovecheese.com"",""cacheUrl"":""http://www.google.com/search?q\u003dcache:GBhRR8ytMhQJ:www.ilovecheese.com"",""title"":""I Love \u003cb\u003eCheese\u003c/b\u003e!, Homepage"",""titleNoFormatting"":""I Love Cheese!, Homepage"",""content"":""The American Dairy Association\u0026#39;s official site includes recipes and information   on nutrition and storage of \u003cb\u003echeese\u003c/b\u003e.""},{""GsearchResultClass"":""GwebSearch"",""unescapedUrl"":""http://www.gnome.org/projects/cheese/"",""url"":""http://www.gnome.org/projects/cheese/"",""visibleUrl"":""www.gnome.org"",""cacheUrl"":""http://www.google.com/search?q\u003dcache:jvfWnVcSFeQJ:www.gnome.org"",""title"":""\u003cb\u003eCheese\u003c/b\u003e"",""titleNoFormatting"":""Cheese"",""content"":""\u003cb\u003eCheese\u003c/b\u003e uses your webcam to take photos and videos, applies fancy special effects   and lets you share the fun with others. It was written as part of Google\u0026#39;s \u003cb\u003e...\u003c/b\u003e""}],""cursor"":{""pages"":[{""start"":""0"",""label"":1},{""start"":""4"",""label"":2},{""start"":""8"",""label"":3},{""start"":""12"",""label"":4},{""start"":""16"",""label"":5},{""start"":""20"",""label"":6},{""start"":""24"",""label"":7},{""start"":""28"",""label"":8}],""estimatedResultCount"":""14400000"",""currentPageIndex"":0,""moreResultsUrl"":""http://www.google.com/search?oe\u003dutf8\u0026ie\u003dutf8\u0026source\u003duds\u0026start\u003d0\u0026hl\u003den-GB\u0026q\u003dcheese""}}, ""responseDetails"": null, ""responseStatus"": 200}";
        g1 = JSONHelper.Deserialise<GoogleSearchResults>(json);

        foreach (Pages x in g1.responseData.cursor.pages)
        {
            // Anything you want to get
            Response.Write(x.label);

        }
    }
}

public class JSONHelper
{
    public static T Deserialise<T>(string json)
    {
        using (var ms = new MemoryStream(Encoding.Unicode.GetBytes(json)))
        {
            var serialiser = new DataContractJsonSerializer(typeof(T));
            return (T)serialiser.ReadObject(ms);
        }
    }

    public static string Serialize<T>(T obj)
    {
        DataContractJsonSerializer serializer = new DataContractJsonSerializer(obj.GetType());
        using (MemoryStream ms = new MemoryStream())
        {
            serializer.WriteObject(ms, obj);
            return Encoding.Default.GetString(ms.ToArray());
        }
    }
}

[DataContract]
public class GoogleSearchResults
{
    [DataMember]
    public ResponseData responseData { get; set; }

    [DataMember]
    public string responseStatus { get; set; }

}


public class ResponseData
{
    [DataMember]
    public Cursor cursor { get; set; }

    [DataMember]
    public IEnumerable<Results> results { get; set; }


}


[DataContract]
public class Cursor
{
    [DataMember]
    public IEnumerable<Pages> pages { get; set; }
}



[DataContract]
public class Pages
{
    [DataMember]
    public string start { get; set; }

    [DataMember]
    public string label { get; set; }

}


[DataContract]
public class Results
{
    [DataMember]
    public string unescapedUrl { get; set; }

    [DataMember]
    public string url { get; set; }

    [DataMember]
    public string visibleUrl { get; set; }

    [DataMember]
    public string cacheUrl { get; set; }

    [DataMember]
    public string title { get; set; }

    [DataMember]
    public string titleNoFormatting { get; set; }

    [DataMember]
    public string content { get; set; }
}
 

5voto

Martin Dimitrov Puntos 1843

Traté de usar el código anterior, pero no funcionó. La estructura JSON devuelto por Google es tan diferente y hay un fallo muy importante en la función auxiliar: una llamada a DataContractJsonSerializer.ReadObject() que realmente deserializa los datos JSON en el objeto.

Aquí está el código que funciona en el 2011:

 using System;
using System.Runtime.Serialization;
using System.Runtime.Serialization.Json;
using System.IO;
using System.Text;
using System.Collections.Generic;

namespace <YOUR_NAMESPACE>
{
    public class JSONHelper
    {
        public static T Deserialise<T>(string json)
        {
            T obj = Activator.CreateInstance<T>();
            MemoryStream ms = new MemoryStream(Encoding.Unicode.GetBytes(json));
            DataContractJsonSerializer serialiser = new DataContractJsonSerializer(obj.GetType());
            obj = (T)serialiser.ReadObject(ms);
            ms.Close();
            return obj;
        }
    }

    public class Result
    {
        public string GsearchResultClass { get; set; }
        public string unescapedUrl { get; set; }
        public string url { get; set; }
        public string visibleUrl { get; set; }
        public string cacheUrl { get; set; }
        public string title { get; set; }
        public string titleNoFormatting { get; set; }
        public string content { get; set; }
    }

    public class Page
    {
        public string start { get; set; }
        public int label { get; set; }
    }

    public class Cursor
    {
        public string resultCount { get; set; }
        public Page[] pages { get; set; }
        public string estimatedResultCount { get; set; }
        public int currentPageIndex { get; set; }
        public string moreResultsUrl { get; set; }
        public string searchResultTime { get; set; }
    }

    public class ResponseData
    {
        public Result[] results { get; set; }
        public Cursor cursor { get; set; }
    }

    public class GoogleSearchResults
    {
        public ResponseData responseData { get; set; }
        public object responseDetails { get; set; }
        public int responseStatus { get; set; }
    }
}
 

Para obtener el contenido del primer resultado, hacer:

 GoogleSearchResults googleResults = new GoogleSearchResults();
googleResults = JSONHelper.Deserialise<GoogleSearchResults>(jsonData);
string contentOfFirstResult = googleResults.responseData.results[0].content;
 

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