日历控件Calendar使用技巧－－根据数据库数据控制日期背景显示颜色

    protected DataSet ds;
    protected void Page_Load(object sender, EventArgs e)
    {
            Calendar1.VisibleDate = DateTime.Today;
            FillDataset();
    }
    protected void FillDataset()
    {
        DateTime firstDate = new DateTime(Calendar1.VisibleDate.Year,
            Calendar1.VisibleDate.Month, 1);
        DateTime lastDate = GetFirstDayOfNextMonth();
        ds = GetCurrentMonthData(firstDate, lastDate);
    }

    protected DateTime GetFirstDayOfNextMonth()
    {
        int monthNumber, yearNumber;
        if (Calendar1.VisibleDate.Month == 12)
        {
            monthNumber = 1;
            yearNumber = Calendar1.VisibleDate.Year + 1;
        }
        else
        {
            monthNumber = Calendar1.VisibleDate.Month + 1;
            yearNumber = Calendar1.VisibleDate.Year;
        }
        DateTime lastDate = new DateTime(yearNumber, monthNumber, 1);
        return lastDate;
    }

    protected DataSet GetCurrentMonthData(DateTime firstDate,DateTime lastDate)
    {
        DataSet dsMonth = new DataSet();
        ConnectionStringSettings cs;
        cs = ConfigurationManager.ConnectionStrings["qztvoaConnectionString"];
        String connString = cs.ConnectionString;
        SqlConnection dbConnection = new SqlConnection(connString);
        String query;
        query = "SELECT DISTINCT plandate FROM tplan WHERE plandate >= @firstDate AND plandate < @lastDate";
        SqlCommand dbCommand = new SqlCommand(query, dbConnection);
        dbCommand.Parameters.Add(new SqlParameter("@firstDate",firstDate));
        dbCommand.Parameters.Add(new SqlParameter("@lastDate", lastDate));
        SqlDataAdapter sqlDataAdapter = new SqlDataAdapter(dbCommand);
        try
        {
            sqlDataAdapter.Fill(dsMonth);
        }
        catch {}
        return dsMonth;
    }
    protected void Calendar1_DayRender(object sender, DayRenderEventArgs e)
    {
        DateTime nextDate;
        if (ds!= null)
        {
            Label1.Text = ds.Tables.Count.ToString();
            foreach (DataRow dr in ds.Tables[0].Rows)
            {
                nextDate = (DateTime)dr["plandate"];
                if (nextDate == e.Day.Date)
                {
                    e.Cell.BackColor = System.Drawing.Color.Red;
                }
            }
        }
    }