OnClientClick和RequiredFieldValidator同時使用會存在衝突問題，而導致RequiredFieldValidator失效
解決方法：
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="ButtonConfirm1.aspx.cs" Inherits="ButtonConfirm1" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>ButtonConfirm</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
<asp:RequiredFieldValidator ID="RequiredFieldValidator1" runat="server" ControlToValidate="TextBox1"
ErrorMessage="不可為空白"></asp:RequiredFieldValidator>
<br />
<asp:Button ID="Button2" runat="server" Text="送出" OnClientClick="return ConfirmMe()" />
</div>
</form>
</body>
</html><script type="text/javascript">
function ConfirmMe()
{
if(Page_ClientValidate())
{
return confirm('確定送出嗎?');
}
else
{
return false;
}
}
</script>增加Page_ClientValidate()判斷