Date Select On Show DataGridView

  string constring = "Data Source=localhost\\SQLEXPRESS;Initial Catalog=bar_db;Integrated Security=True";
            SqlConnection con = new SqlConnection(constring);
            DateTime dt = new DateTime();
            dt = Convert.ToDateTime(dateTimePicker1.Value.ToShortDateString());
            SqlCommand cmd = new SqlCommand();
            string sqlqry = "select mbrchrg AS MemberCharge,costumechrg AS CostumerCharge,Date from swimpool where Date = '" + dt + "'";
            dataGridView1.DataSource = "";
            cmd.CommandText = sqlqry;
            cmd.CommandType = CommandType.Text;
            cmd.Connection = con;
            SqlDataAdapter da = new SqlDataAdapter(cmd);
            da.SelectCommand = cmd;
            DataSet ds = new DataSet();
            da.Fill(ds, "swimpool");
            dataGridView1.DataSource = ds.Tables["swimpool"].DefaultView;




-------------------------------------------------------------------------
namespace HotelManagement
{
    public partial class User_Record : Form
    {
        Dbclass db = new Dbclass();
        string common;
        public User_Record()
        {
            InitializeComponent();
        }

        private void btnExit_Click(object sender, EventArgs e)
        {
            this.Close();
        }

        private void User_Record_Load(object sender, EventArgs e)
        {
            DataTable dt = new DataTable();

            string str = "select Addmminisator,User_Id,User_Type,User_Name,User_Password from user_master";
            dt = db.FindFun(str);
            grduser_record.DataSource  = dt;
            totalrecord.Text = Convert.ToInt32(grduser_record.Rows.Count - 1).ToString();

        }

        private void btnpreview_Click(object sender, EventArgs e)
        {
            Crstluser_master use = new Crstluser_master();
            Frmviewr view = new Frmviewr();
            DataTable dt = new DataTable();
            string str = " Select * from user_Master";
            dt = db.FindFun(str);

            use.SetDataSource(dt);
            view.crstlviewer.ReportSource = use;
            view.Show();
        }
    }
}