Show image in picturebox using path saved in database

Question

I got a table 'IMAGES' with fields 'img_username' , 'img_image_path. From my form I can upload image path to database and copy the image to a specific folder. Now I want to show the image in a pictureboxaccording the username I am giving. I will share the code so far iwritten. Please help. Now am getting error when I try to show image by giving a username.An unhandled exception of type 'System.IO.FileNotFoundException' occurred in System.Drawing.dll... This is the error showing at line 49. Is there any better way to do it?

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 System.Configuration;
using System.Data.SqlClient;
using System.IO;

namespace ImageSaving
{
    public partial class Form1 : Form
    {
        SqlConnection con = new SqlConnection(ConfigurationManager.AppSettings.Get("connectionstring").ToString());
        string displayimg, filepath;
        string folderpath = @"D:\Images\";
        OpenFileDialog open = new OpenFileDialog();
        SqlCommand cmd;
        public Form1()
        {
            InitializeComponent();
        }


//show image button

        private void btn_ShowImage_Click(object sender, EventArgs e)
        {
            string sql = "select * from images where img_username=@username";

            SqlCommand cmdrtrv = new SqlCommand(sql, con);
            cmdrtrv.Parameters.AddWithValue("@username", txt_UserName.Text);

            try
            {
                if (con.State == ConnectionState.Closed)
                {
                    con.Open();
                }
                using (SqlDataReader reader = cmdrtrv.ExecuteReader())
                {
                    if (reader.Read())
                    {
                        string path = @reader["img_path"].ToString();
                        pctbx_UserImage.Image = Image.FromFile("" + reader["path"].ToString());
                    }
                }

            }
            finally
            {
                con.Close();
            }

        }

        private void Form1_Load(object sender, EventArgs e)
        {
            con.Open();

        }
//Search image button for upload

        private void btn_SearchImage_Click(object sender, EventArgs e)
        {
            open.Filter = "Image Files(*.jpg; *.jpeg; *.gif; *.bmp)|*.jpg; *.jpeg; *.gif; *.bmp|all files|*.*";
            if(open.ShowDialog()==DialogResult.OK)
            {
                displayimg = open.SafeFileName;
                txt_ImagePath.Text = open.FileName;
                //Bitmap img = new Bitmap(open.FileName);
                pctbx_UserImage.Image = new Bitmap(open.FileName);
                filepath = open.FileName;
            }
        }

//Upload button

        private void btn_Upload_Click(object sender, EventArgs e)
        {
            if(filepath=="")
            {
                cmd.Parameters.AddWithValue("@Path", "");
            }
            else
            {

                cmd = new SqlCommand("insert into images values(@UserName,@Path)",con);
                cmd.CommandType = CommandType.Text;
                cmd.Parameters.AddWithValue("@UserName", txt_UserName.Text);
                cmd.Parameters.AddWithValue("@Path", folderpath+Path.GetFileName(open.FileName));
                File.Copy(filepath, Path.Combine(folderpath, Path.GetFileName(open.FileName)),true);
                if(con.State==ConnectionState.Closed)
                {
                    con.Open();
                }
                cmd.ExecuteNonQuery();
                MessageBox.Show("Image Saved");
                con.Close();
            }
        }
    }
}