Help with: Unable to cast object 2

[aalmeida]

Unable to cast object of type 'System.Data.Linq.Binary' to type 'System.Byte[]'.
Another C# Linq to SQL issue this time with Image datatype conversion.
The situation is this:
I add an image to a database table to a column that is type Image using the folowing process:

/// <summary>
        /// The insert Personal Info method.
        /// Using a stored procedure for insert data.
        /// </summary>
private Int32 newSigCard()
        {
            SigCardLinqDataContext db = new SigCardLinqDataContext();
            var q = db.usp_newassinante(  
                                  name_txtbx.Text.ToString()
                                , cpf_txtbx.Text.ToString()
                                , rg_txtbx.Text.ToString()                                
                                , abrev_txt.Text.ToString()
                                , civil_txt.Text.ToString()
                                , profissao_txt.Text.ToString()
                                , nascimento_txt.Text.ToString()
                                , rua_txt.Text.ToString()
                                , bairro_txt.Text.ToString()
                                , cidade_txt.Text.ToString()
                                , uf_txt.Text.ToString()
                                , cep_txt.Text.ToString());
        return q;
        }
        
        /// <summary>
        /// The insert image method to add new scaned signature 
        /// to a specific assinante.
        /// Using a stored procedure for image data.
        /// </summary>
        private Int32 newSigImg(Int32 id, Binary sigimg)
        {
            //Int32 id, Binary sigimg
            SigCardLinqDataContext db = new SigCardLinqDataContext();
            Int32 newimage_id = db.usp_newscanedimage(id, sigimg);

            return (newimage_id);
        }
/// <summary>
/// The Save action.
/// To start the process to add the personal data and the personal imag to the database.
/// </summary>
private void Salvar_Click(object sender, EventArgs e)
        {
            Int32 Card_id = newSigCard();
            Bitmap img = (Bitmap)newImagesrc;
            // First we have to convert the Bitmap into a Binary data type 
            // Assuming img is an Image object:
            MemoryStream stream = new MemoryStream();
            img.Save(stream, System.Drawing.Imaging.ImageFormat.Bmp);
            Byte[] imgbytes = stream.ToArray();
            //And finally we put the string to the sproc  
            Int32 Image_id = newSigImg(Card_id, (Binary)imgbytes);
        }

And this is the process to retrieve the data from the database and display it on the form:

/// <summary>
/// The Function to convert the Binary datatype from the database into bitmap to display.
/// </summary>
private void PictureFormat(object sender, ConvertEventArgs e)
        {
            // e.Value is the original value
            Byte[] img = (Byte[])e.Value;
            MemoryStream ms = new MemoryStream();
            int offset = 0;
            ms.Write(img, offset, img.Length - offset);
            Bitmap bmp = new Bitmap(ms);
            ms.Close();

            // Writes the new value back
            e.Value = bmp;
        }

/// <summary>
/// Retrieve the data from the database and put it in the form controls.
/// </summary>
private void dataGridView1_CellContentClick(object sender, DataGridViewCellEventArgs e)
        {
            int colIndex = e.ColumnIndex;
            int rowIndex = e.RowIndex;
            if (rowIndex >= 0 && colIndex >= 0)
            {
                DataGridViewRow theRow = dataGridView1.Rows[rowIndex];
                // Write a line for each control that needs to 
                // be filed with information from the Linq Sproc
                // Get a typed table to run queries.
                SigCardLinqDataContext dc = new SigCardLinqDataContext();
                Table<vw_all> Assinaturas = dc.GetTable<vw_all>();
                IQueryable<vw_all> q = from c in Assinaturas
                        where c.card_id == (int)theRow.Cells[0].Value
                        select c;
  
              foreach (vw_all a in q)
                {

                Binding bdPhoto = new Binding("Image", a, "scan_img");
                bdPhoto.Format += new ConvertEventHandler(this.PictureFormat);
                assinaturas_img.DataBindings.Add(bdPhoto);
                //assinaturas_img.Image = image; //.FromStream(a.scan_img);// byte[Convert.ToInt32(a.scan_img)];
                assinaturas_img.Visible = true;
                
                }

I'm getting the following erro on PictureFormat(object sender, ConvertEventArgs e) at Byte[] img = (Byte[])e.Value;
Unable to cast object of type 'System.Data.Linq.Binary' to type 'System.Byte[]'.

AL Almeida
CIO

http://www.artdigitalonline.com/

May all those that come behind us, find us faithful.

 

[jmeckley]

http://lmgtfy.com/?q=convert+System.Data.Linq.Binary+to+byte+array&l=1

Jason Meckley
Programmer
Specialty Bakers, Inc.

faq855-7190

 

[aalmeida]

yes! I had searched all over the internet but this post had what I needed. quick and easy thanks.
For the benefit of all the others that might get hear looking for a solution I had to modify the display foreeach part of the program as below:

foreach (vw_all a in q)
                {

                byte[] bdPhoto = (byte[])(a.scan_img).ToArray();
                assinaturas_img.Image = Image.FromStream(new MemoryStream(bdPhoto));
                //assinaturas_img.Image = image; //.FromStream(a.scan_img);// byte[Convert.ToInt32(a.scan_img)];
                assinaturas_img.Visible = true;
                
                }

This eliminates the need for the PictureFormat function.

Thanks,

AL Almeida
CIO

http://www.artdigitalonline.com/

May all those that come behind us, find us faithful.