使用c＃检索blob时参数无效

Question

我试图以BLOB格式检索保存在数据库中的图片 但它给出了一个异常，即MemoryStream的参数在此行

中无效

pictureBox1.Image = System.Drawing.Image.FromStream(ms);

这是完整的代码：

    using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using MySql.Data.MySqlClient;
using System.IO;

namespace InsertImage2
{
    public partial class Form1 : Form
    {
        MySqlConnection myConn = new MySqlConnection("datasource=localhost;port=****;username=****;password=****;");
        MySqlCommand cmd;
        MySqlDataAdapter da;
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            string query = "select * from images_database.images where id = '"+textBox1.Text+"';";
            cmd = new MySqlCommand(query, myConn);
            da = new MySqlDataAdapter(cmd);
            DataTable dt = new DataTable();
            da.Fill(dt);

            byte[] img = (byte[])dt.Rows[0][1];
            MemoryStream ms = new MemoryStream(img);
            pictureBox1.Image = System.Drawing.Image.FromStream(ms);
            da.Dispose();
        }
    }
}