Dapper TypeHandler.SetValue() not being called

我正在测试Dapper，以便将对象加载/持久化到Oracle数据库，并且要管理Oracle的Guid存储，我需要一个SqlMapper.TypeHandler<Guid>。当从数据库加载Guid列时，会调用Parse方法，但当我尝试使用Guid参数执行SQL语句时，我会得到以下异常：

System.ArgumentException未处理；消息=值未下降在预期范围内。Source=Oracle.DataAccess.

在调试中，我可以看到从数据库加载类时调用了处理程序的Parse（）方法，但没有调用SetValue（）mdethod。

再现异常的代码低于

---

CREATE TABLE foo (id     RAW (16) NOT NULL PRIMARY KEY,
                  name   VARCHAR2 (30) NOT NULL);
INSERT INTO foo (id, name) VALUES (SYS_GUID (), 'Bar');
COMMIT;

---

using System;
using System.Linq;
using Dapper;
using Oracle.DataAccess.Client;
namespace Program
{
    public class Foo
    {
        public Guid Id { get; set; }
        public string Name { get; set; }
    }
    class GuidTypeHandler : SqlMapper.TypeHandler<Guid>
    {
        public override Guid Parse(object value)
        {
            Console.WriteLine("Handling Parse of {0}", value);
            var inVal = (byte[])value;
            byte[] outVal = new byte[] { inVal[3], inVal[2], inVal[1], inVal[0], inVal[5], inVal[4], inVal[7], inVal[6], inVal[8], inVal[9], inVal[10], inVal[11], inVal[12], inVal[13], inVal[14], inVal[15] };
            return new Guid(outVal);
        }
        public override void SetValue(System.Data.IDbDataParameter parameter, Guid value)
        {
            Console.WriteLine("Handling Setvalue of {0}", value);
            var inVal = value.ToByteArray();
            byte[] outVal = new byte[] { inVal[3], inVal[2], inVal[1], inVal[0], inVal[5], inVal[4], inVal[7], inVal[6], inVal[8], inVal[9], inVal[10], inVal[11], inVal[12], inVal[13], inVal[14], inVal[15] };
            parameter.Value = outVal;
        }
    }
    class Program
    {
        static void Main(string[] args)
        {
            SqlMapper.AddTypeHandler<Guid>(new GuidTypeHandler());
            var conn = new OracleConnection(Resources.ConnectionString);
            var def = new CommandDefinition("select id, name from foo");
            conn.Open();
            var foo = conn.Query<Foo>(def).First();
            Console.WriteLine(foo.Id + "; " + foo.Name);
            foo.Name = "New Bar";
            def = new CommandDefinition(
                "UPDATE foo SET name = :name WHERE id = :id",
                parameters: new { ID = foo.Id, NAME = foo.Name });
            var rows = conn.Execute(def);
            Console.WriteLine("{0} rows inserted", rows);
            Console.ReadLine();
        }
    }
}

SqlMapper.AddTypeHandler<Guid>(new GuidTypeHandler());
SqlMapper.RemoveTypeMap(typeof(Guid));
SqlMapper.RemoveTypeMap(typeof(Guid?));

public class GuidAsStringHandler : SqlMapper.TypeHandler<Guid>
{
    public override Guid Parse(object value)
    {
        return new Guid((string) value);
    }
    public override void SetValue(IDbDataParameter parameter, Guid value)
    {
        parameter.Value = value.ToString();
    }
}

public class OracleGuid
{
    private Guid dotNetGuid;
    public OracleGuid(Guid guid)
    {
        this.dotNetGuid = guid;
    }
    public OracleGuid(Byte[] byteArray)
    {
        this.dotNetGuid = new Guid(byteArray);
    }
    public Guid InternalGuid { get { return dotNetGuid; } }
}

public class OracleGuidHandler : SqlMapper.TypeHandler<OracleGuid>
{
    public override OracleGuid Parse(object value)
    {
        return new OracleGuid((byte[]) value);
    }
    public override void SetValue(System.Data.IDbDataParameter parameter, OracleGuid value)
    {
        parameter.Value = value.InternalGuid.ToByteArray();
    }
}

public class FooDto
{
    public OracleGuid Id { get; set; }
    public string Name { get; set; }
}