在执行查询时面临问题

Question

  

可能重复：
  facing problem while executing vb.net query

我无法通过执行equree显示结果，即

Dim con As SqlConnection
        con = New SqlConnection("server=chinna; uid=sa; pwd=136018@h; database=icms;")
        con.Open()
        Dim cmd As SqlCommand
        cmd = New SqlCommand("select * from personal where idno=@param", con)
        cmd.Parameters.AddWithValue("param", TextBox1.Text)


        Dim rdr As SqlDataReader
        rdr = cmd.ExecuteReader()
        If rdr.Read() Then
            GridView1.Visible = True
            GridView1.DataBind()


        End If