Gridview uppdateras inte direkt ASP.net

protected void newPostBtn_Click(object sender, EventArgs e)
        {
            SqlConnection thisConnection = new SqlConnection(@Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\Database1.mdf;Integrated Security=True;User Instance=True);
            thisConnection.Open();
            SqlCommand cmd = thisConnection.CreateCommand();
            cmd.CommandText = "INSERT INTO Post (Message, Time) VALUES (@Message, @Time)";

            cmd.Parameters.Add("@Message", SqlDbType.VarChar, 200);
            cmd.Parameters.Add("@Time", SqlDbType.DateTime);
            cmd.Parameters["@Message"].Value = TextBox1.Text;
            cmd.Parameters["@Time"].Value = DateTime.Now;

            SqlDataSource1.

            cmd.ExecuteNonQuery();
            thisConnection.Close();
            
            Update();

        }

        protected void Update() 
        {
            UpdatePanel1.Update();
        }