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[C#]How to retrieve LONGBLOB image from mysql in picturebox

Hello,
I need to retrieve the longblob of a picture from mysql.
So first I insert it in the database with this:

MemoryStream ms = new MemoryStream();
                  //  PIC_Image.Image.Save(ms, PIC_Image.Image.RawFormat);
                    byte[] img = ms.ToArray();
 
                    string q = "insert into tb_produits (Image) values('" + img+ "')";

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Here is to retrieve the picture :

public static Bitmap ByteToImage(byte[] blob)
        {
            MemoryStream mStream = new MemoryStream();
            byte[] pData = blob;
            mStream.Write(pData, 0, Convert.ToInt32(pData.Length));
            Bitmap bm = new Bitmap(mStream, false);
            mStream.Dispose();
            return bm;
 
        }
 
 MySqlDataAdapter sda = new MySqlDataAdapter("SELECT * FROM tb_produits WHERE Designation='" + Designation + "'and Reference='" + Reference + "'", MyConnexion);
            DataTable dt = new DataTable();
 
            sda.Fill(dt);
            if (dt.Rows.Count == 1)
            {
                byte[] img = (byte[])dt.Rows[0]["Image"];
 
             
 
              
                PIC_Image.Image = ByteToImage(img);
            }

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I tried to retrieve but I got an error:
Parameter is not valid in this line " Bitmap bm = new Bitmap(mStream, false);"

AndyAinscow

MemoryStream ms = new MemoryStream();
                  //  PIC_Image.Image.Save(ms, PIC_Image.Image.RawFormat);
                    byte[] img = ms.ToArray();
                    string q = "insert into tb_produits (Image) values('" + img+ "')";

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img is empty when you save it. Hence your failure when you retrieve it.

SniperCode Sheva

ASKER

It is not empty because in the database I see this : "[BLOB - 13 o]"

AndyAinscow

This is your code:

new memory stream with nothing in it
MemoryStream ms = new MemoryStream();

convert empty memory stream to empty byte array = no picure
byte[] img = ms.ToArray();

insert the empty byte array into the database
string q = "insert into tb_produits (Image) values('" + img+ "')";

SniperCode Sheva

ASKER

I forgot to edit this PIC_Image.Image.Save(ms, PIC_Image.Image.RawFormat);

AndyAinscow

You had that in your code but commented out. Please post your code that you use - without editing it

SniperCode Sheva

ASKER

 MemoryStream ms = new MemoryStream();
                   PIC_Image.Image.Save(ms, PIC_Image.Image.RawFormat);
                   
                    byte[] img = ms.GetBuffer();
string q = "insert into tb_produits (Image) values('" + img+ "')";

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Image is of type Blob

AndyAinscow

OK. Lets try to see which bits of code work by modifying things slightly.

MemoryStream ms = new MemoryStream();
PIC_Image.Image.Save(ms, PIC_Image.Image.RawFormat);

byte[] img = ms.GetBuffer();

See if this line here works - converting your image to a blob and then back to the bitmap without using the database.
Bitmap bm = ByteToImage(img);

string q = "insert into tb_produits (Image) values('" + img+ "')";

ASKER CERTIFIED SOLUTION

SniperCode Sheva

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