[ASP]DropDownList Date Picker

ASP控制項內建的Calendar在美觀上不賴，但日期卻不太方便！

之前又常在別人的網站裡，看到用DropDownList來做挑選日期的控制項。

於是就著手來試一個，藉由幾個控制項就可以達成！

環境：VS2012

1. .aspx的Form內容

其中使用UpdatePanel(因此需要ScriptManager)，受限於Panel自動換行，使用Table tag來做處理

            <asp:ScriptManager ID="scriptManager" runat="server"></asp:ScriptManager>
            <table>
                <tr>
                    <td>
                        <asp:UpdatePanel ID="up_month" runat="server" UpdateMode="Conditional" ChildrenAsTriggers="false">
                            <ContentTemplate>
                                <asp:DropDownList ID="ddl_month" DataTextField="monthText" DataValueField="monthValue" OnSelectedIndexChanged="ddl_month_SelectedIndexChanged" AutoPostBack="true" runat="server"></asp:DropDownList>
                            </ContentTemplate>
                        </asp:UpdatePanel>
                    </td>
                    <td>
                        <asp:UpdatePanel ID="up_day" runat="server" UpdateMode="Conditional">
                            <ContentTemplate>
                                <asp:DropDownList ID="ddl_day" runat="server" ></asp:DropDownList>
                            </ContentTemplate>
                            <Triggers>
                                <asp:AsyncPostBackTrigger ControlID="ddl_month" EventName="SelectedIndexChanged" />
                            </Triggers>
                        </asp:UpdatePanel>
                    </td>
                    <td>
                        <asp:DropDownList ID="ddl_year" runat="server"></asp:DropDownList>
                    </td>
                </tr>
            </table>

2. Code Behide

為了使用DateTimeFormatInfo，請先引用：

using System.Globalization;

剩餘的是設定DDL的內容的程式碼

protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            //Populate DropDownLists
            ddlMonth.DataSource = Enumerable.Range(1, 12).Select(a => new
            {
                MonthName = DateTimeFormatInfo.CurrentInfo.GetMonthName(a),
                MonthNumber = a
            });
            ddlMonth.DataBind();
            ddlYear.DataSource = Enumerable.Range(DateTime.Now.Year - 99, 100).Reverse();
            ddlYear.DataBind();
            ddlday.DataSource = Enumerable.Range(1, DateTime.DaysInMonth(DateTime.Now.Year, Convert.ToInt32(ddlMonth.SelectedValue)));
            ddlday.DataBind();
        }
    }
    protected void ddlMonth_SelectedIndexChanged(object sender, EventArgs e)
    {
        ddlday.DataSource = Enumerable.Range(1, DateTime.DaysInMonth(DateTime.Now.Year, Convert.ToInt32(ddlMonth.SelectedValue)));
        ddlday.DataBind();
       
    }

DateTimePicker