Question

C#怎么读取varbinary字段的值

Answer 1

C#操作varbinary(MAX)字段 - zhouhb - 博客园

http://www.cnblogs.com/zhouhb/archive/2013/02/13/2910808.html

using (SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["db"].ConnectionString))
            {
                String sql = "select * from emp where id=@id";
                SqlCommand cmd = new SqlCommand(sql, conn);
                cmd.Parameters.AddWithValue("@id", id);
                conn.Open();
                using (SqlDataReader dr = cmd.ExecuteReader())
                {
                    if(dr.Read())
                    {
                        textBox1.Text = dr[1].ToString();
                        textBox2.Text = dr[2].ToString();
                        if (!dr.IsDBNull(3))
                        {
                            System.Data.SqlTypes.SqlBytes bytes = dr.GetSqlBytes(3);//3是varbinary列从零开始的列序号。bytes.Stream能返回一个用于读取的Stream对象

                        }
                    }
                }
            }