Error: when Image data convert to pdf from DataGridView tbl.

Sumonto Mehedi

Im trying to convert DataGridView data with image column which is filtered from my SQL Db into a PDF file in C# I wrote this code using iTextSharp!
but I got Error like this: "unable to cast object of type System.Drawing.bitmap to type system byte[]"

Can anyone help me out kindly?

Here is My Code:
Thanks !!!

foreach (DataGridViewCell cell in row.Cells)
{
if(row.Cells[0].Value!= null)
{
pdfTable.AddCell(row.Cells[0].Value.ToString());
}
if (row.Cells[1].Value != null)
{
byte[] img = (byte[])row.Cells[1].Value;
pdfTable.AddCell(iTextSharp.text.Image.GetInstance(img));
}
}

17 Replies

Know the answer? Post it — somebody with the same question will find it here.

Amit Mohanty6y ago
Accepted answer
The thing to remember about ImageConverter, is that the image will be directly converted into bytes. Thus an image in BMP format and the same image in png format will NOT have the same byte array. So if you want to compare two images, for example, you would have to make sure they are first in the same format before comparing their byte arrays. So try the below code to convert image to byte.
ImageConverter _imageConverter = new ImageConverter();
byte[] xByte = (byte[])_imageConverter.ConvertTo(row.Cells[1].Value, typeof(byte[]));
Or try the below code to save the image to database.
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("@Image", photo_aray);
Sumonto Mehedi6y ago
UPDATE:

its worked with VS17 community edition
vs19 community got me huge time to knowing lot of things. Last time i changed for each loop with for loop, & Noticed that- in
int n = dataGridView1.Rows.Count;
for(int i = 0; i
{
byte[] img = (byte[])dataGridView1.Rows[i].Cells[2].Value;
pdfTable.AddCell(iTextSharp.text.Image.GetInstance(img));
}
Row[index] didnt worked with variable but Cells[index] did,
int temp = 2;
byte[] img = (byte[])dataGridView1.Rows[0].Cells[temp].Value;
if i use staright value without using variable it works fine, that time i decided to switch my vs version :)

Sudden you should to fall in a trap, if you overcome with it- you just not survived, also you brought more lessons with it. <3
thanks Amit, Sahoo, Ravi for giving me your valuable time also co-operate with me.

Love you all <3
Sumonto Mehedi6y ago
Hey Amit, thanks for replying me again and again!!!

byte[] img = (byte[])row.Cells[2].Value;
this line is the main problem in my code, i cant understand why this is not working on my machine.. i tested several time by changing database table for inserting value with new code updating time, and save it to DB as byte value. why showing this error again? for testing purpose- i create it 2 times as a new project.. didnt worked. same error have been showing as "unable to cast object of type System.Drawing.bitmap to type system byte[]"

probably you have seen my code also which i attached, can you suggest me any probable case so that, ican solve it?
Thanks!
Laxmidhar Sahoo6y ago
byte[] img = (byte[])(row.Cells[2].Value);
Sumonto Mehedi6y ago
Hey Amit, Sorry for being late.. till now its not working and here is my Attachment, please check!!!
File:
Amit Mohanty6y ago
Hey, check my attached file and if possible please attach your application to check what's wrong in it.
Sumonto Mehedi6y ago
no its not working and now says- "unable to cast object of type System.Drawing.bitmap to type system byte[]"
i changed it
/*ImageConverter _imageConverter = new ImageConverter(); byte[] img = (byte[])_imageConverter.ConvertTo(row.Cells[2].Value, typeof(byte[])); iTextSharp.text.Image image = iTextSharp.text.Image.GetInstance(img);*/
byte[] img = (byte[])row.Cells[2].Value;
pdfTable.AddCell(iTextSharp.text.Image.GetInstance(img));
what should i do!!!!
ohhhhhhhhhhhh
Amit Mohanty6y ago
Hey, Sumonto below code is working fine. Please check the attached file.
byte[] img = (byte[])row.Cells[2].Value;
pdfTable.AddCell(iTextSharp.text.Image.GetInstance(img));
Sumonto Mehedi6y ago
Not Yet Solved :(
i set this up byte and try to convert as a byte value, but this line- byte[] img = (byte[])_imageConverter.ConvertTo(row.Cells[2].Value, typeof(byte[]));
now says- " 'Unable to cast object of type 'System.Byte[]' to type 'System.Drawing.Image "

Didnt working all of yours approaches for the Datagridview image column value conversion Yet!! Why its not working- i dont know, here is my full code, pls help me to find actual bug.
Thanks:)
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.Data.SqlClient;
using System.IO;
using iTextSharp.text.pdf;
using iTextSharp.text;

namespace Test01
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        SqlConnection con = new SqlConnection(@"Data Source=JUSTDREAM-PC\SQLEXPRESS;Initial Catalog=Testfeb2020;Integrated Security=True");
        //byte[] Pics;
        private void button1_Click(object sender, EventArgs e)
        {
            System.Drawing.Image img = pictureBox1.Image;
            byte[] pic;
            ImageConverter conv = new ImageConverter();
            pic = (byte[])conv.ConvertTo(img, typeof(byte[]));
            //Pics = pic;

            String q = "INSERT INTO Tbl_FinalTest1(ID, Grade, Pic) VALUES ('" + textBox1.Text + "', '" + textBox2.Text + "', @Pic)";
            con.Open();
            SqlCommand cmd = new SqlCommand(q, con);

            cmd.Parameters.AddWithValue("@Pic", pic);
            cmd.ExecuteNonQuery();

            con.Close();
            MessageBox.Show("Insertion OK");
        }

        private void button2_Click(object sender, EventArgs e)
        {
            con.Open();
            String q = "SELECT * FROM Tbl_FinalTest1";
            SqlDataAdapter SDA = new SqlDataAdapter(q, con);
            DataTable dt = new DataTable();
            SDA.Fill(dt);
            dataGridView1.DataSource = dt;
            con.Close();
        }

        private void button3_Click(object sender, EventArgs e)
        {
            if (dataGridView1.Rows.Count > 0)
            {
                SaveFileDialog sfd = new SaveFileDialog();
                sfd.Filter = "PDF (*.pdf)|*.pdf";
                sfd.FileName = "Output.pdf";
                bool fileError = false;
                if (sfd.ShowDialog() == DialogResult.OK)
                {
                    if (File.Exists(sfd.FileName))
                    {
                        try
                        {
                            File.Delete(sfd.FileName);
                        }
                        catch (IOException ex)
                        {
                            fileError = true;
                            MessageBox.Show("It wasn't possible to write the data to the disk." + ex.Message);
                        }
                    }
                    if (!fileError)
                    {
                        try
                        {
                            PdfPTable pdfTable = new PdfPTable(dataGridView1.Columns.Count);
                            pdfTable.DefaultCell.Padding = 3;
                            pdfTable.WidthPercentage = 100;
                            pdfTable.HorizontalAlignment = Element.ALIGN_LEFT;

                            foreach (DataGridViewColumn column in dataGridView1.Columns)
                            {
                                PdfPCell cell = new PdfPCell(new Phrase(column.HeaderText));
                                pdfTable.AddCell(cell);
                            }

                            foreach (DataGridViewRow row in dataGridView1.Rows)
                            {

                                if (row.Cells[0].Value != null)
                                {
                                    pdfTable.AddCell(row.Cells[0].Value.ToString());
                                }
                                if (row.Cells[1].Value != null)
                                {
                                    pdfTable.AddCell(row.Cells[1].Value.ToString());
                                }

                                if (row.Cells[2].Value != null)
                                {
                                    //pdfTable.AddCell(row.Cells[2].Value.ToString());

                                    /*ImageConverter _imageConverter = new ImageConverter();
                                    byte[] img = (byte[])_imageConverter.ConvertTo(row.Cells[2].Value, typeof(byte[]));
                                    pdfTable.AddCell(iTextSharp.text.Image.GetInstance(img));
                                    // pdfTable.AddCell(iTextSharp.text.Image.GetInstance(Pics));
                                    */


                                    float[] widths = new float[] { 0.9f, 3f };

                                    ImageConverter _imageConverter = new ImageConverter();
                                    byte[] img = (byte[])_imageConverter.ConvertTo(row.Cells[2].Value, typeof(byte[]));
                                    //Pics = img;
                                    iTextSharp.text.Image image = iTextSharp.text.Image.GetInstance(img);

                                    image.ScaleAbsolute(100f, 70f);
                                    PdfPCell cellImg = new PdfPCell(image);
                                    cellImg.Border = 0;
                                    pdfTable.AddCell(cellImg);
                                }
                            }

                            using (FileStream stream = new FileStream(sfd.FileName, FileMode.Create))
                            {
                                Document pdfDoc = new Document(PageSize.A4, 10f, 20f, 20f, 10f);
                                PdfWriter.GetInstance(pdfDoc, stream);
                                pdfDoc.Open();
                                pdfDoc.Add(pdfTable);
                                pdfDoc.Close();
                                stream.Close();
                            }

                            MessageBox.Show("Data Exported Successfully !!!", "Info");
                        }
                        catch (Exception ex)
                        {
                            MessageBox.Show("Error Not Solved Yet:" + ex.Message);
                        }
                    }
                }
            }
            else
            {
                MessageBox.Show("No Record To Export !!!", "Info");
            }
        }

        private void button4_Click(object sender, EventArgs e)
        {
            using (OpenFileDialog ofd = new OpenFileDialog())
            {
                if (ofd.ShowDialog() == DialogResult.OK)
                {
                    pictureBox1.Image = System.Drawing.Image.FromFile(ofd.FileName);
                }
            }
        }
    }
}
Laxmidhar Sahoo6y ago
hi
Try the bellow code and call it for converting
public byte[] imageToByteArray(System.Drawing.Image imageIn)
{
MemoryStream ms = new MemoryStream();
imageIn.Save(ms,System.Drawing.Imaging.ImageFormat.Gif);
return  ms.ToArray();
}
Sumonto Mehedi6y ago
Thanks Laxmidhar Sahoo
but a datagridview image column genarated as a bitmap image, now first task is convert this as a byte[] , here it doesnt work for convert bitmap to byte. its the main problem now, can you give me some suggestion kindly??
Thanks!
Sumonto Mehedi6y ago
Hi Amit, i use image datatype in my db, and here is my code of image conversion to store to db..
private void button1_Click(object sender, EventArgs e)
       {

           //Image Conversion

           System.Drawing.Image img = pictureBox1.Image;
           byte[] pic;
           ImageConverter conv = new ImageConverter();
           pic = (byte[])conv.ConvertTo(img, typeof(byte[]));

           con.Open();
           String q = "INSERT INTO Tbl_MJS(Serial, Name, Mobile, Grade, AVP, Image)" +
               "VALUES ('" + textBox1.Text + "', '" + textBox3.Text + "', '" + textBox2.Text + "', '" +
               comboBox2.Text + "', '" + comboBox1.Text + "', @Image)";

           SqlCommand cmd = new SqlCommand(q, con);
           cmd.Parameters.AddWithValue("@Image", pic);
           cmd.ExecuteNonQuery();

           con.Close();
           MessageBox.Show("Insetion OK");

           // block end
       }
Amit Mohanty6y ago
Hey Sumonto, what is your datatype of image field in your db?
Laxmidhar Sahoo6y ago
hi
Perhaps you did not set the width of the image and direct add the image with create from itextsharp.
Bellow is the code try may help you
if (row.Cells[5].Value != null)
            {
            float[] widths = new float[] { 0.9f, 3f };
                byte[] img = (byte[])row.Cells[5].Value;
            iTextSharp.text.Image image = iTextSharp.text.Image.GetInstance(img);
            image.ScaleAbsolute(100f, 70f);
            PdfPCell cellImg = new PdfPCell(image);
            cellImg.Border = 0;
            tablel.AddCell(cellImg);

            }
Ravi Patel6y ago
Hi ,

refer this it might be help you

https://www.c-sharpcorner.com/UploadFile/009464/how-to-export-gridview-to-pdf-using-itextsharp-library/
Sumonto Mehedi6y ago
here goes all code, pls check:
rechecking 60 -63 lines are ambiguous
private void button5_Click(object sender, EventArgs e)
        {
            if (dataGridView1.Rows.Count > 0)
            {
                SaveFileDialog sfd = new SaveFileDialog();
                sfd.Filter = "PDF (*.pdf)|*.pdf";
                sfd.FileName = "Output.pdf";
                bool fileError = false;
                if (sfd.ShowDialog() == DialogResult.OK)
                {
                    if (File.Exists(sfd.FileName))
                    {
                        try
                        {
                            File.Delete(sfd.FileName);
                        }
                        catch (IOException ex)
                        {
                            fileError = true;
                            MessageBox.Show("It wasn't possible to write the data to the disk." + ex.Message);
                        }
                    }
                    if (!fileError)
                    {
                        try
                        {
                            PdfPTable pdfTable = new PdfPTable(dataGridView1.Columns.Count);
                            pdfTable.DefaultCell.Padding = 3;
                            pdfTable.WidthPercentage = 100;
                            pdfTable.HorizontalAlignment = Element.ALIGN_LEFT;

                            foreach (DataGridViewColumn column in dataGridView1.Columns)
                            {
                                PdfPCell cell = new PdfPCell(new Phrase(column.HeaderText));
                                pdfTable.AddCell(cell);
                            }

                            foreach (DataGridViewRow row in dataGridView1.Rows)
                            {
                                if(row.Cells[0].Value!= null)
                                {
                                    pdfTable.AddCell(row.Cells[0].Value.ToString());
                                }
                                if (row.Cells[1].Value != null)
                                {
                                    pdfTable.AddCell(row.Cells[1].Value.ToString());
                                }
                                if (row.Cells[2].Value != null)
                                {
                                    pdfTable.AddCell(row.Cells[2].Value.ToString());
                                }
                                if (row.Cells[3].Value != null)
                                {
                                    pdfTable.AddCell(row.Cells[3].Value.ToString());
                                }
                                if (row.Cells[4].Value != null)
                                {
                                    pdfTable.AddCell(row.Cells[4].Value.ToString());
                                }
                                if (row.Cells[5].Value != null)
                                {
                                    byte[] img = (byte[])row.Cells[5].Value;
                                    pdfTable.AddCell(iTextSharp.text.Image.GetInstance(img));

                                }

                            }

                            using (FileStream stream = new FileStream(sfd.FileName, FileMode.Create))
                            {
                                Document pdfDoc = new Document(PageSize.A4, 10f, 20f, 20f, 10f);
                                PdfWriter.GetInstance(pdfDoc, stream);
                                pdfDoc.Open();
                                pdfDoc.Add(pdfTable);
                                pdfDoc.Close();
                                stream.Close();
                            }

                            MessageBox.Show("Data Exported Successfully !!!", "Info");
                        }
                        catch (Exception ex)
                        {
                            MessageBox.Show("Error123 :" + ex.Message);
                        }
                    }
                }
            }
            else
            {
                MessageBox.Show("No Record To Export !!!", "Info");
            }
        }
Laxmidhar Sahoo6y ago
hi
Can you display the object creation of pdfTable. More code is better