Question

我在表格中创建了图片列mediumblob

保存我使用以下代码的图像

byte[] ImageData;
fs = new FileStream(fileName, FileMode.Open, FileAccess.Read);
ImageData = new byte[Convert.ToInt32(fs.Length)];
fs.Read(ImageData, 0, Convert.ToInt32(fs.Length));
fs.Close();

string qry = "Update admin_info set `img`='"+ ImageData + "' where id='AD001";

using (con = new MySqlConnection(DBConStr))
{
    con.Open();
    using (cmd = new MySqlCommand(qry, con))
    {
         cmd.ExecuteNonQuery();
    }
}
    MessageBox.Show(" Profile Picture Updated Successfully!", "Success!", MessageBoxButtons.OK, MessageBoxIcon.Information);

并且它是成功的但是使用下面的代码

将其检索到图片框时参数无效

using (MySqlConnection conn = new MySqlConnection("Server = localhost; Port = 3307; database = attendance; uid = root; pwd = MJN45720!"))
{
     conn.Open();
     string myQuery = "SELECT img FROM admin_info where id='AD001'";

     using (MySqlCommand cmd = new MySqlCommand(myQuery, conn))
     {
         using (var reader = cmd.ExecuteReader())
         {
              while (reader.Read())
              {
                   byte[] x = (byte[])reader["img"];
                   MemoryStream ms = new MemoryStream(x);
                   pictureBox1.Image = new Bitmap(ms); //Parameter invalid in this line
               }
         }
     }

搜索了许多论坛并且厌倦了他们在每个帖子中提出的建议，但我无法解决..

Answer 1

您无法正确将图像保存到数据库中。行alias subl="/mnt/c/Program\ Files/Sublime\ Text\ 2/sublime_text.exe"将导致 subl .因为您正在将字节数组转换为字符串，这将仅导致类型名称。您必须将字节数组转换为HEX字符串，这应该被SQL引擎接受。

Answer 2

        byte[] ImageData;
        fs = new FileStream(fileName, FileMode.Open, FileAccess.Read);
        br = new BinaryReader(fs);
        ImageData = br.ReadBytes((int)fs.Length);
        br.Close();
        fs.Close();

       using (con = new MySqlConnection(DBConStr))
        {
            con.Open();
            using (cmd = new MySqlCommand(qry, con))
            {
                cmd.Parameters.Add("@pimage", MySqlDbType.Blob);
                cmd.Parameters["@pimage"].Value = ImageData;
                cmd.ExecuteNonQuery();
            }
        }

这解决了我的问题并且我也能够回复..感谢Honz指出将其转换为刺痛的实际问题：）

参数无效在从mysql中恢复保存的图像时出错c＃

2 个答案: