c#中使用cmd.Parameters.AddWithValue存入数据库

 DBHelper D = new DBHelper();
                MySqlConnection M = D.getconn();
                M.Open();
                MySqlCommand cmd = new MySqlCommand("insert into test1(name,department,specification,amount,packing,declarationInspectionDate,assayDate,reportDate,commodityBatchNumber,inspectionbasis,conclusion,assessor,analyst,laboratoryTechnician) values(@name,@department,@specification,@amount,@packing,@declarationInspectionDate,@assayDate,@reportDate,@commodityBatchNumber,@inspectionbasis,@conclusion,@assessor,@analyst,@laboratoryTechnician)",M);
                cmd.CommandType = CommandType.Text;
                cmd.Parameters.AddWithValue("@name", this.textBox1.Text.Trim());
                cmd.Parameters.AddWithValue("@department", this.textBox2.Text.Trim());
                cmd.Parameters.AddWithValue("@specification", this.textBox3.Text.Trim());
                cmd.Parameters.AddWithValue("@amount", float.Parse(this.textBox4.Text.Trim().ToString()));
                cmd.Parameters.AddWithValue("@packing", this.textBox5.Text.Trim());
                cmd.Parameters.AddWithValue("@declarationInspectionDate", this.dateTimePicker1.Text.Trim());
                cmd.Parameters.AddWithValue("@assayDate", this.dateTimePicker2.Text.Trim());
                cmd.Parameters.AddWithValue("@reportDate", this.dateTimePicker3.Text.Trim());
                cmd.Parameters.AddWithValue("@commodityBatchNumber", this.textBox8.Text.Trim());
                cmd.Parameters.AddWithValue("@inspectionbasis", this.textBox10.Text.Trim());
                cmd.Parameters.AddWithValue("@conclusion", this.textBox11.Text.Trim());
                cmd.Parameters.AddWithValue("@assessor", this.textBox14.Text.Trim());
                cmd.Parameters.AddWithValue("@analyst", this.textBox13.Text.Trim());
                cmd.Parameters.AddWithValue("@laboratoryTechnician", this.textBox12.Text.Trim());
                int j = cmd.ExecuteNonQuery();

用以上代码，我为什么不能实现对数据库的操作？显示插入成功，但是数据库中相应字段全都是空的，也就是说，cmd.Parameters.AddWithValue("@laboratoryTechnician", this.textBox12.Text.Trim());中没有给相应的参数赋值，一个也没有，很难受，我不知道怎么改才行。

        try
        {
           M.Open();

        }
        catch (SqlException ex)
        {
                            Response.Write(ex.Message);
        }
        catch (IOException ex)
        { 
                            Response.Write(ex.Message);
                    }
        finally
        {
           M.Close();
        }




                    捕获一下异常

J返回的是1么？
M.close()写了么？

M.close()写了么？检查一下！