Qfyilyi

i am using windows form, i write a code for getting a image from database in picture box when combo box value is selected. my code is working correctly when combo box value is select and show the data (only show data that have a image). BUT i have a data without a image, when i select combo box value to show data that have no image, it show me a "ERROR" - "Parameter is not valid".

i tried if condition on it but code don't work for me.

here is the code...

    private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)

    {

        try

        {

            using (SQLiteConnection conn = new SQLiteConnection("Data Source=combolist.db;Version=3;"))

            {

                string CommandText = "SELECT * FROM combo WHERE [Id]=@id";

                using (SQLiteCommand cmd = new SQLiteCommand(CommandText, conn))

                {

                    cmd.Parameters.AddWithValue("@id", comboBox1.SelectedItem.ToString());

                    conn.Open();

                    cmd.ExecuteNonQuery();

                    DataTable dt = new DataTable();

                    SQLiteDataAdapter da = new SQLiteDataAdapter(cmd);

                    da.Fill(dt);

                    foreach (DataRow dr in dt.Rows)

                    {

                        textBox1.Text = dr["Id"].ToString();

                        textBox2.Text = dr["FirstName"].ToString();

                        textBox3.Text = dr["LastName"].ToString();

                        textBox4.Text = dr["Age"].ToString();

                        textBox5.Text = dr["Address"].ToString();



                        byte img = (byte)(dr["Pic"]);

                        if (img == null)

                        {

                            pictureBox1.Image = null;

                        }

                        else

                        {

                            MemoryStream ms = new MemoryStream(img);

                            pictureBox1.Image = System.Drawing.Image.FromStream(ms);

                        }

                    }

                }

            }

        }

        catch (Exception ex)

        {

            MessageBox.Show(ex.Message);

        }

    }

help please....

This cast byte img = (byte)(dr["Pic"]); throw the error if value is null.

I would check if dr["Pic"] != null and then:

if(dr["Pic"] != null){

      MemoryStream ms = new MemoryStream((byte)(dr["Pic"]));

      pictureBox1.Image = ms != null ? System.Drawing.Image.FromStream(ms) : null;

 } else {

    pictureBox1.Visible = false;

    //or pictureBox1.Image = null;

 }

Update:
This: cmd.Parameters.AddWithValue("@id", comboBox1.SelectedItem.ToString()); should be cmd.Parameters.AddWithValue("@id", comboBox1.SelectedValue.ToString());