Converting an image to byte array and back again

Question

I realize that this question has been asked before and has answers, but not in this specific way. I have been trying to figure this out for about 7 hours now.

I have a picture that I convert to a byte array to store in an Access database (.mdb)

[Image] -> [byte Array] -> [Access Database(field is an OLE object)] ^ I can do this part fine, done here:

public byte[] ImageToByte(Image img)
{
    Bitmap BmpImage = new Bitmap(img);
    BmpImage.Save(Application.StartupPath + @"\unmodified.png", System.Drawing.Imaging.ImageFormat.Png);
    MemoryStream mStream = new MemoryStream();
    PartPhoto.Image.Save(mStream, System.Drawing.Imaging.ImageFormat.Png);
    byte[] imgAsByte = mStream.ToArray();
    return imgAsByte;
}

Then I Store all of my data in my database like this:

    Part p = new Part();
    p.PartCode = IPC.Text; 
    p.PartName = IPN.Text;
    p.PartDesc = IDESC.Text;
 -->p.PartPhoto = ImageToByte(PartPhoto.Image);
    p.PartSize = size;
    p.PartWeight = weight;
    p.PartType = IPT.Text;
    p.LeadTime = ILT.Text;
    p.PartCost = ICOST.Text;
    p.PartQuantity = IQNT.Text;

    d.Insert(p);

The Insert method does this:

 command.CommandText = "Insert INTO PartInfo (PartCode, PartName, PartDesc, PartPhoto, PartSize, PartWeight, PartType, LeadTime, PartCost, PartQuantity) VALUES('" + p.PartCode + "', '" + p.PartName + "', '" + p.PartDesc + "', '@Pic', '" + p.PartSize + "', '" + p.PartWeight + "', '" + p.PartType + "', '" + p.LeadTime + "', '" + p.PartCost + "', '" + p.PartQuantity + "')";
                    command.Parameters.Add("@Pic", p.PartPhoto);
command.CommandType = CommandType.Text;
connection.Open();
command.ExecuteNonQuery();

It shows up in my database (in the OLE object field) as long binary data. I read from the database into a DataGridView like this:

 String query = "SELECT * FROM PartInfo WHERE PartName CONTAINS " + "\"" + PN + "\"";
 connection.Open();
 da.SelectCommand = new OleDbCommand(query, connection);
 da.Fill(dt);

I then call:

PartGrid.DataSource = d.dt;
PartGrid.Refresh();

To refresh the grid.

Here is my problem. I can't read the byte array back from the DataGridView. I tried a couple different ways, always getting the same error: "Parameter is not valid"

byte[] picBytes = (byte[])PartGrid.Rows[row].Cells[3].Value;
MemoryStream ms = new MemoryStream(picBytes);
Image partPic = Image.FromStream(ms); //ERROR: "Parameter is not valid"
Bitmap bmp = new Bitmap(partPic);
bmp.Save(Application.StartupPath + @"\test.png", System.Drawing.Imaging.ImageFormat.Png);
return partPic;

I call convert from byte array to image like this:

PartPhoto.Image = ImageFromByte(e.RowIndex); 

Like I said, I've been stuck on this for hours now, and it's getting irritating.

Answer 1

Try using System.IO.File.ReadAllBytes to convert your image to a byte array and System.IO.File.WriteAllBytes to convert it back.