When using output parameter values you need to check that the value is not DBNull before using it…
using (SqlConnection conn = new SqlConnection())
{
conn.ConnectionString = System.Configuration.ConfigurationManager.AppSettings.Get("DBConnection").ToString();
conn.Open();
using (SqlCommand cmd = new SqlCommand())
{
cmd.Connection = conn;
cmd.CommandType = CommandType.StoredProcedure;
cmd.Parameters.Add(new SqlParameter("@ChapterId", _ChapterId));
cmd.Parameters.Add(new SqlParameter("@Sequence", _Sequence));
cmd.CommandText = "Get_ContentPrevNext";
SqlParameter parameterPreviousId = new SqlParameter("@PreviousId", System.Data.SqlDbType.Int)
{
Direction = System.Data.ParameterDirection.Output
};
cmd.Parameters.Add(parameterPreviousId);
SqlParameter parameterNextId = new SqlParameter("@NextId", System.Data.SqlDbType.Int)
{
Direction = System.Data.ParameterDirection.Output
};
cmd.Parameters.Add(parameterNextId);
cmd.ExecuteNonQuery();
if (parameterPreviousId.Value != DBNull.Value)
{
_PreviousId = Convert.ToInt32(parameterPreviousId.Value);
}
if (parameterNextId.Value != DBNull.Value)
{
_NextId = Convert.ToInt32(parameterNextId.Value);
}
}
}
