为什么我无法从mysql获取映像？

Question

我无法从mysql blob获取图像。我尝试了以下代码，但它给了我这个错误：“连接必须有效且打开”。请注意，我正在使用WPF。 开放连接布尔：

public bool OpenConnection()
{
    try
    {
        conn.Open();
        return true;
    }
    catch (MySqlException ex)
    {
        switch (ex.Number)
        {
            case 0:
                MessageBox.Show("Neuspesna konekcija na server!");
                break;
            case 1045:
                MessageBox.Show("Korisnicko ime i Lozinka za server su pogresno unete!");
                break;
        }
        return false;
    }
}

laodImg方法：这是问题所在，但我无法理解它的哪一部分...

public void LoadImg()
{
    PocetnaStrana ps = new PocetnaStrana();
    try
    {
        if (OpenConnection())
        {
            MySqlCommand cmd = new MySqlCommand("SELECT profPic FROM Korisnici WHERE id=4");
            MySqlDataReader rdr1 = cmd.ExecuteReader();
            while (rdr1.Read())
            {
                byte[] data = (byte[])rdr1[0]; // 0 is okay if you only selecting one column
                //And use:
                using (System.IO.MemoryStream ms = new System.IO.MemoryStream(data))
                {
                     var imageSource = new BitmapImage();
                     imageSource.BeginInit();
                     imageSource.StreamSource = ms;
                     imageSource.CacheOption = BitmapCacheOption.OnLoad;
                     imageSource.EndInit();

                     // Assign the Source property of your image
                     ps.profPicBX.Source = imageSource;
                     rdr1.Close();
                 }
             }
         }
         else
         {
             conn.Close();
         }
    }
    catch (Exception ex)
    {
         MessageBox.Show("something is wrong: " + ex);           
    }
}