网络服务页面 System.IndexOutOfRangeException

Question

public class GetAreaFromCity : System.Web.Services.WebService
{
    [WebMethod]
    public GetAreaByCityId ClassForGetCIty(int City_Id)
    {
        string CS =ConfigurationManager.ConnectionStrings["FOODINNConnectionString"].ConnectionString;

        using (SqlConnection con = new SqlConnection(CS))
        {
            SqlCommand cmd = new SqlCommand("spGetCityById",con);
            cmd.CommandType = CommandType.StoredProcedure;
            SqlParameter parameter = new SqlParameter("@ID", City_Id);

            //To assiate this parameter object with cmd object
            cmd.Parameters.Add(parameter);
            GetAreaByCityId GETAreaByCityId =new GetAreaByCityId();
            con.Open();
            SqlDataReader reader = cmd.ExecuteReader();

            //as WeakReference read data wewant ToString retrive Column value & then polute this property City_Id values
            while (reader.Read()){
                GETAreaByCityId.City_Id = Convert.ToInt32(reader["City_Id"]);
                GETAreaByCityId.Area_Id =     Convert.ToInt32(reader["Area_Id"]);

            }
            return GETAreaByCityId;

            //ToString return sql
        }
    }
}

这是我的服务页面代码

public class GetAreaByCityId
{
    public int Ca_Id {get;set; }
    public int City_Id { get; set; }
    public int Area_Id { get; set; }
}

这是 class 按城市获取区域

Create Proc [dbo].[spGetCityById]
@ID int 
as
Begin
Select Area_Id from 
CITIES_AREA where City_Id = @ID
End
GO

及以上可检索数据的数据库程序

System.IndexOutOfRangeException: City_Id at System.Data.ProviderBase.FieldNameLookup.GetOrdinal(String fieldName) at System.Data.SqlClient.SqlDataReader.GetOrdinal(String name) at System.Data.SqlClient.SqlDataReader.get_Item(String name) at WebApplication1.GetAreaFromCity.ClassForGetCIty(Int32 City_Id) in c:\Users\Mudassir\Documents\Visual Studio 2013\Projects\WebApplication1\WebAppli

上面的错误我不知道是什么问题

Answer 1

您的存储过程仅返回 Area_Id。 "while loop" while (reader.Read()){ 中的代码试图从两列读取数据：

City_Id
Area_Id

您可以将列 City_Id 添加到存储过程查询的结果集中，但您已经拥有该值，因为您将它作为参数传递给存储过程。

最简单的解决方法可能就是更改这一行：

GETAreaByCityId.City_Id = Convert.ToInt32(reader["City_Id"]);

对此：

GETAreaByCityId.City_Id = City_Id;

网络服务页面 System.IndexOutOfRangeException

web service page System.IndexOutOfRangeException

asp.net

asmx