ปุ่มค้นหาใช้ไม่ได้ครับ เขียนโคดแล้วช่วยดูให้หน่อยครับ C# Ms Access

string strConn;
        OleDbConnection Conn = new OleDbConnection(); 
        OleDbDataAdapter da;  
        DataSet ds = new DataSet();  
        bool IsFind = false;
        string radioCh = "";

        private void StockForm_Load(object sender, EventArgs e)
        {
            strConn = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=D:/DB_Shop.accdb";
            if (Conn.State == ConnectionState.Open)
            {
                Conn.Close();
            }
            Conn.ConnectionString = strConn;
            Conn.Open();
            ShowAllStock(); 
        }
        private void ShowAllStock()
        {
            string sqlStock;
            sqlStock = "Select * from tb_stock";
            if (IsFind == true)ds.Tables["tb_stock"].Clear(); 

            da = new OleDbDataAdapter(sqlStock, Conn);
            da.Fill(ds, "tb_stock");  
            if (ds.Tables["tb_stock"].Rows.Count != 0)
            {
                IsFind = true;
                DGVStock.ReadOnly = true;
                DGVStock.DataSource = ds.Tables["tb_stock"];
            }
            else IsFind = false;
        }
      
  private void button1_Click(object sender, EventArgs e)
        {
             if (textBarCode.Text == "")
                {
                    MessageBox.Show("กรุณากรอกรหัสสินค้า", "ยืนยัน");

                }
                else
                {
                    string sqlSearch;
                    OleDbCommand comSearch = new OleDbCommand();
                    sqlSearch = "Select * From tb_stock Where BarCode='" + textBarCode.Text + "'";
                    comSearch.CommandText = sqlSearch;
                    comSearch.Connection = Conn;
                    comSearch.ExecuteNonQuery();
ShowAllStock(); 
                }
}