为什么Asp:Button的ID为submit，Calender控件就无法选择日期。若命名其他内容则可以。
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="WebForm1.aspx.cs" Inherits="UI.WebForm1" %>
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
<title></title>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:Calendar ID="Calendar1" runat="server"></asp:Calendar>
<asp:Button ID="submit" runat="server" />
</div>
</form>
</body>
</html>
