I do correct my code. But its still showing this error msg

hi ,

change your connection string to below line

when you add

i have downloaded your code initially i found that connection object is not initializting that's why you are gettting object reference exception

Please change this one line of code and try once...

con = new SqlConnection(@"Data Source = LUNASOFTRESEARC\\SQLSERVER; Initial Catalog = test; Integrated Security = True") 

 

Please le me know if you face any problem.

Yes I do zip it.

Have a look please I am in need. 

Thank you to say something. These is the table definition table and the whole codes:

 

CREATE TABLE [dbo].[Student] (
[sno] INT NOT NULL,
[sname] VARCHAR (50) NULL,
[course] VARCHAR (50) NULL,
[fee] MONEY NULL,
[photo] IMAGE NULL,
PRIMARY KEY CLUSTERED ([sno] ASC)
); 

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Drawing.Imaging;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Data.SqlClient;
using System.Data.Sql;
using System.IO;
using Microsoft.VisualBasic;

namespace inserting_imgs
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}

SqlConnection con;
SqlCommand cmd;
SqlDataAdapter adapter;
DataSet ds; int rno = 0;
MemoryStream ms;
byte[] photo_aray;

private void Form1_Load(object sender, EventArgs e)
{
con = new SqlConnection("@Data Source = LUNASOFTRESEARC\\SQLSERVER; Initial Catalog = test; Integrated Security = True");
loaddata();
showdata();
}
void loaddata()
{
adapter = new SqlDataAdapter("select sno,sname,course,fee,photo from student", con);
adapter.MissingSchemaAction = MissingSchemaAction.AddWithKey;
ds = new DataSet(); adapter.Fill(ds, "student");
}

void showdata()
{
if (ds.Tables[0].Rows.Count > 0)
{
textBox1.Text = ds.Tables[0].Rows[rno][0].ToString();
textBox2.Text = ds.Tables[0].Rows[rno][1].ToString();
textBox3.Text = ds.Tables[0].Rows[rno][2].ToString();
textBox4.Text = ds.Tables[0].Rows[rno][3].ToString();
pictureBox1.Image = null;
if (ds.Tables[0].Rows[rno][4] != System.DBNull.Value)
{
photo_aray = (byte[])ds.Tables[0].Rows[rno][4];
MemoryStream ms = new MemoryStream(photo_aray);
pictureBox1.Image = Image.FromStream(ms);
}
}
else
MessageBox.Show("No Records");
}

private void browse_Click(object sender, EventArgs e)
{
openFileDialog1.Filter = "jpeg|*.jpg|bmp|*.bmp|all files|*.*";
DialogResult res = openFileDialog1.ShowDialog();
if (res == DialogResult.OK)
{
pictureBox1.Image = Image.FromFile(openFileDialog1.FileName);
}
}

private void newbtn_Click(object sender, EventArgs e)
{
cmd = new SqlCommand("select max(sno)+10 from student", con);
//con.Open();
if (con.State != ConnectionState.Open)
con.Open();
textBox1.Text = cmd.ExecuteScalar().ToString();
con.Close();
textBox2.Text = textBox3.Text = textBox4.Text = "";
pictureBox1.Image = null;
}

private void insert_Click(object sender, EventArgs e)
{
cmd = new SqlCommand("insert into student(sno,sname,course,fee,photo) values(" + textBox1.Text + ",'" +
textBox2.TabIndex + "','" + textBox3.Text + "'," + textBox4.Text + ",@photo)", con);
conv_photo();
//con.Open();
if (con.State != ConnectionState.Open)
con.Open();
int n = cmd.ExecuteNonQuery();
con.Close();
if (n > 0)
{
MessageBox.Show("record inserted");
loaddata();
}
else
MessageBox.Show("insertion failed");
}
void conv_photo()
{
//converting photo to binary data
if (pictureBox1.Image != null)
{
//using MemoryStream:
ms = new MemoryStream();
pictureBox1.Image.Save(ms, ImageFormat.Jpeg);
byte[] photo_aray = new byte[ms.Length];
ms.Position = 0;
ms.Read(photo_aray, 0, photo_aray.Length);
cmd.Parameters.AddWithValue("@photo", photo_aray);
}
}

private void search_Click(object sender, EventArgs e)
{
try
{
int n = Convert.ToInt32(Interaction.InputBox("Enter sno:", "Search", "20", 100, 100));
DataRow drow;
drow = ds.Tables[0].Rows.Find(n);
if (drow != null)
{
rno = ds.Tables[0].Rows.IndexOf(drow);
textBox1.Text = drow[0].ToString();
textBox2.Text = drow[1].ToString();
textBox3.Text = drow[2].ToString();
textBox4.Text = drow[3].ToString();
pictureBox1.Image = null;
if (drow[4] != System.DBNull.Value)
{
photo_aray = (byte[])drow[4];
MemoryStream ms = new MemoryStream(photo_aray);
pictureBox1.Image = Image.FromStream(ms);
}
}
else
MessageBox.Show("Record Not Found");
}
catch
{
MessageBox.Show("Invalid Input");
}
}

private void update_Click(object sender, EventArgs e)
{
cmd = new SqlCommand("update student set sname='" + textBox2.Text + "', course='" + textBox3.Text + "', fee='" + textBox4.Text + "', photo=@photo where sno=" + textBox1.Text, con);
conv_photo();
con.Open();
int n = cmd.ExecuteNonQuery();
con.Close();
if (n > 0)
{
MessageBox.Show("Record Updated");
loaddata();
}
else
MessageBox.Show("Updation Failed");
}

private void delete_Click(object sender, EventArgs e)
{
cmd = new SqlCommand("delete from student where sno=" + textBox1.Text, con);
con.Open();
int n = cmd.ExecuteNonQuery();
con.Close();
if (n > 0)
{
MessageBox.Show("Record Deleted");
loaddata();
rno = 0;
showdata();
}
else
MessageBox.Show("Deletion Failed");
}

private void first_Click(object sender, EventArgs e)
{
rno = 0; showdata();
MessageBox.Show("First record");
}

private void previous_Click(object sender, EventArgs e)
{
if (rno > 0)
{
rno--; showdata();
}
else
MessageBox.Show("First record");
}

private void next_Click(object sender, EventArgs e)
{
if (rno < ds.Tables[0].Rows.Count - 1)
{
rno++; showdata();
}
else
MessageBox.Show("Last record");
}

private void last_Click(object sender, EventArgs e)
{
rno = ds.Tables[0].Rows.Count - 1;
showdata(); MessageBox.Show("Last record");
}

private void exit_Click(object sender, EventArgs e)
{
this.Close();
}
}

 

This exception generally occur when you are trying to access its variables/methods which is null.

 

I couldn't found the connection class, make sure that you had initialized somewhere globally

 

var con = new SqlConnection (...);