C# Newtonsoft.Json.JsonSerializationException(从';System.Data.SqlTypes.SqlDouble上的';value&';获取值时出错)序列化SqlGeography
我尝试在SQL server 2012数据库中使用Newtonsoft.Json版本“Newtonsoft.Json.10.0.3”将C# Newtonsoft.Json.JsonSerializationException(从';System.Data.SqlTypes.SqlDouble上的';value&';获取值时出错)序列化SqlGeography,c#,sql-server,json,geolocation,json.net,C#,Sql Server,Json,Geolocation,Json.net,我尝试在SQL server 2012数据库中使用Newtonsoft.Json版本“Newtonsoft.Json.10.0.3”将DataTable对象序列化为Json 该表有一个类型为“geography”的列,其中包含类型为的实例 用于生成json的代码: public string SerializeToJson() { var connstring1 ="Data Source=server1;Initial Catalog=database1;user=
DataTable
对象序列化为Json
该表有一个类型为“geography”的列,其中包含类型为的实例
用于生成json的代码:
public string SerializeToJson()
{
var connstring1 ="Data Source=server1;Initial Catalog=database1;user=xxx;password=yyy";
var sql = "SELECT * FROM table_1 "; //table_1 has a column of type geography
using (var c1 = new SqlConnection(connstring1))
{
c1.Open();
var da = new SqlDataAdapter()
{
SelectCommand = new SqlCommand(sql, c1)
};
DataSet ds1 = new DataSet("table");
da.Fill(ds1, "table");
var dt = ds1.Tables[0];
//serialize to Json
try
{
var options = new JsonSerializerSettings
{
Formatting = Formatting.None
};
//this line fire exception for geography type
var json = JsonConvert.SerializeObject(dt, options);
return json;
}
catch (Exception ex)
{
Console.WriteLine(ex);
}
}
}
我已经安装了sql 2012功能包中的程序集“Microsoft.SqlServer.Types”
我已经创建了一个完整的C#程序(独立于sql server安装),使用带有SqlGeography列的datatable来显示问题
我得到一个错误:
Newtonsoft.Json.JsonSerializationException:从“System.Data.SqlTypes.SqlDouble”上的“value”获取值时出错。“-->
System.Data.SqlTypes.SqlNullValueException:数据为空。
无法对空值调用此方法或属性。
在System.Data.SqlTypes.SqlDouble.get_Value()处
在GetValue(对象)处
位于Newtonsoft.Json.Serialization.DynamicValueProvider.GetValue(对象目标)
我够到了,但它帮不上忙
任何有助于解决问题的方法
编辑:
基于@dbc注释,我提供了用于生成json的完整源代码
完整的错误消息是:
Newtonsoft.Json.JsonSerializationException:从'System.Data.SqlTypes.SqlDouble'上的'value'获取值时出错。“-->System.Data.SqlTypes.SqlNullValueException:数据为空。无法对空值调用此方法或属性。
在System.Data.SqlTypes.SqlDouble.get_Value()处
在GetValue(对象)处
位于Newtonsoft.Json.Serialization.DynamicValueProvider.GetValue(对象目标)
---内部异常堆栈跟踪的结束---
位于Newtonsoft.Json.Serialization.DynamicValueProvider.GetValue(对象目标)
位于Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.CalculatePropertyValues(JsonWriter编写器、对象值、JsonContainerContract、JsonProperty成员、JsonProperty属性、JsonContract和memberContract、对象和成员值)
位于Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializationObject
(JsonWriter编写器,对象值,JsonObjectContract合同,JsonProperty成员,JsonContainerContract集合合同,JsonProperty容器属性)
位于Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeValue(
JsonWriter编写器,对象值,JsonContract valueContract,JsonProperty成员
,JSONCONTAINERCONTAINERCONTAINERCONTAINERCONTRACT,JsonProperty containerProperty)
位于Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializationObject
(JsonWriter编写器,对象值,JsonObjectContract合同,JsonProperty成员,JsonContainerContract集合合同,JsonProperty容器属性)
位于Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeValue(
JsonWriter编写器,对象值,JsonContract valueContract,JsonProperty成员
,JSONCONTAINERCONTAINERCONTAINERCONTAINERCONTRACT,JsonProperty containerProperty)
位于Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.serializate(JsonWriter JsonWriter,对象值,类型objectType)
位于Newtonsoft.Json.Serialization.JsonSerializerProxy.serializationinternal(JsonWriter-JsonWriter,对象值,类型rootType)
在Newtonsoft.Json.Converters.DataTableConverter.WriteJson(JsonWriter,
对象值,JsonSerializer序列化程序)
位于Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.Serializer
表(JsonWriter编写器、JsonConverter转换器、对象值、JsonContract契约、JsonContainerContract集合契约、JsonProperty容器属性)
位于Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeValue(
JsonWriter编写器,对象值,JsonContract valueContract,JsonProperty成员
,JSONCONTAINERCONTAINERCONTAINERCONTAINERCONTRACT,JsonProperty containerProperty)
位于Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.serializate(JsonWriter JsonWriter,对象值,类型objectType)
位于Newtonsoft.Json.JsonSerializer.SerializeInternal(JsonWriter JsonWriter,对象值,类型objectType)
位于Newtonsoft.Json.JsonConvert.SerializeObjectInternal(对象值、类型、JsonSerializer JsonSerializer)
位于Newtonsoft.Json.JsonConvert.SerializeObject(对象值,JsonSerializerSettings设置)
在F:\jsontest.cs中的jsontest.SerializeToJson()处:第104行
Edit2:
我按照@dbc所述启用跟踪,并获得以下日志:
2017-08-24T19:45:31.941 Info开始使用转换器Newtonsoft.Json.Converters.DataTableConverter序列化System.Data.DataTable。路径“”
2017-08-24T19:45:31.972信息已开始序列化Microsoft.SqlServer.Types.SqlGeography。路径“[0].f1”
2017-08-24T19:45:32.003信息已开始序列化System.Data.SqlTypes.SqlInt32.Path'[0].f1.STSrid'
2017-08-24T19:45:32.003信息已完成序列化System.Data.SqlTypes.SqlInt32。路径“[0].f1.STSrid”
2017-08-24T19:45:32.003信息已开始序列化System.Data.SqlTypes.SqlDouble。路径“[0].f1.Lat”
2017-08-24T19:45:32.003信息已完成序列化System.Data.SqlTypes.SqlDouble。路径“[0].f1.Lat”
2017-08-24T19:45:32.003信息已开始序列化System.Data.SqlTypes.SqlDouble。路径“[0].f1.Long”
2017-08-24T19:45:32.003信息已完成序列化System.Data.SqlTypes.SqlDouble。路径“[0].f1.Long”
2017-08-24T19:45:32.003信息已开始序列化System.Data.SqlTypes.SqlDouble。路径“[0].f1.Z”
2017-08-24T19:45:32.003序列化System.Data.SqlTypes.SqlDouble时出错。从“System.Data.SqlTypes.SqlDouble”上的“value”获取值时出错
2017-08-24T19:45:32.003序列化System.Data.DataTable时出错。从“System.Data.SqlTypes.SqlDouble”上的“value”获取值时出错<
public static class SqlPrimitiveConverters
{
public static JsonSerializerSettings AddSqlConverters(this JsonSerializerSettings settings)
{
foreach (var converter in converters)
settings.Converters.Add(converter);
return settings;
}
static readonly JsonConverter[] converters = new JsonConverter[]
{
new SqlBinaryConverter(),
new SqlBooleanConverter(),
new SqlByteConverter(),
new SqlDateTimeConverter(),
new SqlDecimalConverter(),
new SqlDoubleConverter(),
new SqlGuidConverter(),
new SqlInt16Converter(),
new SqlInt32Converter(),
new SqlInt64Converter(),
new SqlMoneyConverter(),
new SqlSingleConverter(),
new SqlStringConverter(),
// TODO: converters for primitives from System.Data.SqlTypes that are classes not structs:
// SqlBytes, SqlChars, SqlXml
// Maybe SqlFileStream
};
}
abstract class SqlPrimitiveConverterBase<T> : JsonConverter where T : struct, INullable, IComparable
{
protected abstract object GetValue(T sqlValue);
public override bool CanConvert(Type objectType)
{
return typeof(T) == objectType;
}
public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
{
T sqlValue = (T)value;
if (sqlValue.IsNull)
writer.WriteNull();
else
{
serializer.Serialize(writer, GetValue(sqlValue));
}
}
}
class SqlBinaryConverter : SqlPrimitiveConverterBase<SqlBinary>
{
protected override object GetValue(SqlBinary sqlValue) { return sqlValue.Value; }
public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
{
if (reader.TokenType == JsonToken.Null)
return SqlBinary.Null;
return (SqlBinary)serializer.Deserialize<byte[]>(reader);
}
}
class SqlBooleanConverter : SqlPrimitiveConverterBase<SqlBoolean>
{
protected override object GetValue(SqlBoolean sqlValue) { return sqlValue.Value; }
public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
{
if (reader.TokenType == JsonToken.Null)
return SqlBoolean.Null;
return (SqlBoolean)serializer.Deserialize<bool>(reader);
}
}
class SqlByteConverter : SqlPrimitiveConverterBase<SqlByte>
{
protected override object GetValue(SqlByte sqlValue) { return sqlValue.Value; }
public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
{
if (reader.TokenType == JsonToken.Null)
return SqlByte.Null;
return (SqlByte)serializer.Deserialize<byte>(reader);
}
}
class SqlDateTimeConverter : SqlPrimitiveConverterBase<SqlDateTime>
{
protected override object GetValue(SqlDateTime sqlValue) { return sqlValue.Value; }
public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
{
if (reader.TokenType == JsonToken.Null)
return SqlDateTime.Null;
return (SqlDateTime)serializer.Deserialize<DateTime>(reader);
}
}
class SqlDecimalConverter : SqlPrimitiveConverterBase<SqlDecimal>
{
protected override object GetValue(SqlDecimal sqlValue) { return sqlValue.Value; }
public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
{
if (reader.TokenType == JsonToken.Null)
return SqlDecimal.Null;
return (SqlDecimal)serializer.Deserialize<decimal>(reader);
}
}
class SqlDoubleConverter : SqlPrimitiveConverterBase<SqlDouble>
{
protected override object GetValue(SqlDouble sqlValue) { return sqlValue.Value; }
public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
{
if (reader.TokenType == JsonToken.Null)
return SqlDouble.Null;
return (SqlDouble)serializer.Deserialize<double>(reader);
}
}
class SqlGuidConverter : SqlPrimitiveConverterBase<SqlGuid>
{
protected override object GetValue(SqlGuid sqlValue) { return sqlValue.Value; }
public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
{
if (reader.TokenType == JsonToken.Null)
return SqlGuid.Null;
return (SqlGuid)serializer.Deserialize<Guid>(reader);
}
}
class SqlInt16Converter : SqlPrimitiveConverterBase<SqlInt16>
{
protected override object GetValue(SqlInt16 sqlValue) { return sqlValue.Value; }
public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
{
if (reader.TokenType == JsonToken.Null)
return SqlInt16.Null;
return (SqlInt16)serializer.Deserialize<short>(reader);
}
}
class SqlInt32Converter : SqlPrimitiveConverterBase<SqlInt32>
{
protected override object GetValue(SqlInt32 sqlValue) { return sqlValue.Value; }
public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
{
if (reader.TokenType == JsonToken.Null)
return SqlInt32.Null;
return (SqlInt32)serializer.Deserialize<int>(reader);
}
}
class SqlInt64Converter : SqlPrimitiveConverterBase<SqlInt64>
{
protected override object GetValue(SqlInt64 sqlValue) { return sqlValue.Value; }
public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
{
if (reader.TokenType == JsonToken.Null)
return SqlInt64.Null;
return (SqlInt64)serializer.Deserialize<long>(reader);
}
}
class SqlMoneyConverter : SqlPrimitiveConverterBase<SqlMoney>
{
protected override object GetValue(SqlMoney sqlValue) { return sqlValue.Value; }
public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
{
if (reader.TokenType == JsonToken.Null)
return SqlMoney.Null;
return (SqlMoney)serializer.Deserialize<decimal>(reader);
}
}
class SqlSingleConverter : SqlPrimitiveConverterBase<SqlSingle>
{
protected override object GetValue(SqlSingle sqlValue) { return sqlValue.Value; }
public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
{
if (reader.TokenType == JsonToken.Null)
return SqlSingle.Null;
return (SqlSingle)serializer.Deserialize<float>(reader);
}
}
class SqlStringConverter : SqlPrimitiveConverterBase<SqlString>
{
protected override object GetValue(SqlString sqlValue) { return sqlValue.Value; }
public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
{
if (reader.TokenType == JsonToken.Null)
return SqlString.Null;
return (SqlString)serializer.Deserialize<string>(reader);
}
}
public class TableRowDTO
{
[JsonConverter(typeof(SqlGeographyConverter))]
public SqlGeography f1 { get; set; }
public int id { get; set; }
}
var settings = new JsonSerializerSettings().AddSqlConverters();
var list = JsonConvert.DeserializeObject<List<TableRowDTO>>(jsonString, settings);
public class SqlGeographyResult
{
private byte[] bytes { get; }
public SqlGeographyResult(SqlGeography geography)
{
bytes = geography.Serialize().Value;
}
public SqlGeography ToGeography()
{
return SqlGeography.Deserialize(new System.Data.SqlTypes.SqlBytes(bytes));
}
}