如何从.net Web服务中获取json答案

【问题标题】：how to get json as a result from .net web service如何从.net Web服务中获取json
【发布时间】：2016-05-02 18:47:25
【问题描述】：

我只是想从 .net 网络服务中获取 json
在安卓应用中使用

我的网络方法是……

        [WebService(Namespace = "http://tempuri.org/")]
        [WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
        [System.ComponentModel.ToolboxItem(false)]
        // To allow this Web Service to be called from script, using ASP.NET AJAX, uncomment the following line. 
        [System.Web.Script.Services.ScriptService]
        public class GetFlash : System.Web.Services.WebService
        {

            [WebMethod]
            [ScriptMethod(ResponseFormat = ResponseFormat.Json)]
            public string GetOneFlash()
            {
                string constring = System.Configuration.ConfigurationManager.ConnectionStrings["eng_lang_tutConnectionString"].ConnectionString;
                SqlConnection con = new SqlConnection(constring);
                con.Open();

                SqlCommand sqlCommand =
                new SqlCommand(@"SELECT * FROM focus WHERE P_ID = " + HttpContext.Current.Request.QueryString["IndexOrder"], con);

                StringBuilder sb = new StringBuilder();
                StringWriter sw = new StringWriter(sb);
                JsonWriter jsonWriter = new JsonTextWriter(sw);

                try
                {
                    SqlDataReader reader = sqlCommand.ExecuteReader();
                    reader.Read();

                    int fieldcount = reader.FieldCount; // count how many columns are in the row
                    object[] values = new object[fieldcount]; // storage for column values
                    reader.GetValues(values); // extract the values in each column

                    jsonWriter.WriteStartObject();
                    for (int index = 0; index < fieldcount; index++)
                    {
                        jsonWriter.WritePropertyName(reader.GetName(index)); // column name
                        jsonWriter.WriteValue(values[index]); // value in column
                    }
                    jsonWriter.WriteEndObject();
                    reader.Close();
                }
                catch (SqlException sqlException)
                {
                    con.Close();
                    return ("No data fetched ..." + "\n" + "---------------------------");
                }
                finally
                {
                    con.Close();
                }
                return sb.ToString();

             }

        }

我的网络服务变得混乱 - 既不是 json 也不是 xml http://englishflash.somee.com/WebService/GetFlash.asmx/GetOneFlash?IndexOrder=1

This XML file does not appear to have any style information associated with it. The document tree is shown below.
<string xmlns="http://tempuri.org/">
{"rownumber":1,"P_ID":120,"F_Eword":"a.m. ","F_Aword":"صباحا ","F_Notes":"","Usage":"","F_pic":null,"F_pronounce":"https://ssl.gstatic.com/dictionary/static/sounds/de/0/a.m..mp3"}
</string>

最大的突破是我得到了这样的 android HTTPrequest 结果

<HTML></HTML>

我所需要的只是来自 .net 网络服务的 json 像这样
https://api.github.com/user/3bdoelnaggar

【问题讨论】：

我不明白为什么你需要使用 JsonWriter 来收缩 json 对象
您可以返回任何对象并将 Json 标记为响应，它会处理所有事情；无需手动准备 Json 字符串
看一个例子codeproject.com/Questions/624676/JSON-Web-service-in-asp-net
我不知道获取 json 对象的正确方法是使用 JsonWriter 还是其他任何我需要的东西 api.github.com/user/3bdoelnaggar

标签： c# json web-services

【解决方案1】：

使用以下内容。这适用于所有 HTTP 调用。它从表中获取字符串并按原样返回。 .NET 将其转换为 JSON。请参阅响应格式部分。

    [System.Web.Services.WebMethod]
    [System.Web.Script.Services.ScriptMethod(ResponseFormat = System.Web.Script.Services.ResponseFormat.Json, UseHttpGet = true)]
    public static string GetDetails(int ID)
    {
       PDetails PDetails = new PDetails();
       OrderManager oOrdManager = new OrderManager();
       PDetails = oOrdManager.GetDetailInformation(ID);
       return PDetails.DetailInfo;       
    }

【讨论】：

【解决方案2】：

我找到了答案问题出在

 return sb.ToString();

我想写

Context.Response.Write(TheSerializer.Serialize(oBoCityList));

完整代码如下

        [WebMethod]
        [ScriptMethod(ResponseFormat = ResponseFormat.Json)]
        public void GetCities()
        {           
            CityList oBoCityList = new CityList() { new City { Name = "New Delhi", ID = 1 }, new City { Name = "Kanpur", ID = 2 }, new City { Name = "Gurgaon", ID = 3 } };
            JavaScriptSerializer TheSerializer = new JavaScriptSerializer();
            //return TheSerializer.Serialize(oBoCityList);
            Context.Response.Write(TheSerializer.Serialize(oBoCityList));
        }
        }
        public class City
        {
            public City() { }
            public string Name
            { get; set; }
            public Int32 ID
            { get; set; }
        }
        public class CityList : List<City>
        {
            public CityList() { }
        }

【讨论】：

【解决方案3】：

以此为例！！

 [WebMethod]
 [ScriptMethod(ResponseFormat = ResponseFormat.Json)]
public void getCustomers()
{
    var clientes = from result in dados.clientes select result;

    Context.Response.Clear();
    Context.Response.ContentType = "application/json";
    Context.Response.Write(JsonConvert.SerializeObject(clientes));  
}

现在，当您创建 Web 方法后，使用此 ajax 调用从 Web 服务获取数据

var url = "YourURL_of_Webservice"; // example :  "http://localhost:54028/webservice.asmx/getCustomers"

$.ajax({
 type: "POST",
 url: url,
 success: function (data) {
  // YOUR CODE FOR SUCCESS BODY
    console.log(data)
 },
 error: function (xmlHttpRequest, textStatus, errorThrown) {
      console.log(xmlHttpRequest.responseText);
      console.log(textStatus);
      console.log(errorThrown);
   }
 });

【讨论】：