Question

Friends,
I have created an application, from that i have tried to upload the pdf files into database and retrieve from database. Upload has been done successfully. But i can’t retrieve that pdf file from database. Please see my code and suggest me a way to come out from this issue.

 protected void Button1_Click(object sender, EventArgs e)
    {
        SqlCommand cmd1 = new SqlCommand("select Docdata from SaveDoc where DocID='" + TextBox1.Text + "'", con);
        con.Open();
        byte[] b = null;
        SqlDataAdapter da = new SqlDataAdapter();
        DataTable dt = new DataTable();
        da = new SqlDataAdapter(cmd1);
        da.Fill(dt);
        if (dt.Rows.Count > 0)
        {
            b = ((byte[])dt.Rows[0][0]); // Error has came here
            Response.ContentType = "application/pdf";
            Response.BinaryWrite(b);

        }

and the error is "Unable to cast object of type ‘System.String’ to type ‘System.Byte[]’."

Answer 1

Do like this:

  b= Encoding.ASCII.GetBytes(dt.Rows[0][0].ToString());