ajax中主要运用js来进行一部读取数据，请教怎么异步读取接收一个数据集，并把这个数据集邦定到一个gridview中呢？请高手帮助阿

public partial class Default4 : System.Web.UI.Page{    private SqlConnection conn;    private SqlCommand cmd;    private SqlDataReader reader;    protected void Page_Load(object sender, EventArgs e)    {        if(!IsPostBack)            AddOnPreRenderCompleteAsync(new BeginEventHandler(BeginAsyncOperation), new EndEventHandler(EndAsyncOperation));    }    IAsyncResult BeginAsyncOperation(object sender, EventArgs e, AsyncCallback cb, object state)    {        string str = System.Web.Configuration.WebConfigurationManager.ConnectionStrings["GtKydjConnectionString"].ConnectionString;        SqlConnection conn = new SqlConnection(str);        cmd = new SqlCommand("select * from GtKydj", conn);        conn.Open();        return cmd.BeginExecuteReader(cb, state);    }    void EndAsyncOperation(IAsyncResult ar)    {        reader = cmd.EndExecuteReader(ar);        GridView1.DataSource = reader;        GridView1.DataBind();    }    public override void Dispose()    {        if (conn != null)            conn.Close();        base.Dispose();    }}