定时器倒计时sql，asp.net c＃，javascript

Question

我正在尝试用javascript，sql，c＃，asp.net编写定时器倒计时代码。

现在的代码是这样的：

<input type="text" id="auctionEndDate" value="<%=TargetDate()%>" style="display:none"/> 
<script language="JavaScript" type="text/javascript"> 


TargetDate = "document.forms[0].auctionEndDate.value"; 
/*this is a property in code behind*/BackColor = "palegreen"; 
ForeColor = "navy"; 
CountActive = true; 
CountStepper = -1; 
LeadingZero = true; 
DisplayFormat = "%%D%% Days, %%H%% Hours, %%M%% Minutes, %%S%% Seconds."; 
FinishMessage = "the auction end" 
</script> 
<script type="text/javascript" language="JavaScript" 
src="http://scripts.hashemian.com/js/countdown.js"></script> 
</script> 

CS文件：

public string TargetDate() 
{ 
    SqlConnection connection = new SqlConnection("Data Source=tcp:***.*****.com;Initial Catalog=DB_***_****;User ID=***_*****_****_user;Password=******;Integrated Security=False;"); 
    string commandtext = "SELECT endTime FROM Timer"; 
    SqlCommand command = new SqlCommand(commandtext, connection); 
    connection.Open(); 
    string tDate = (string)command.ExecuteScalar(); 
    connection.Close(); 
    return tDate; 
} 

定时器DESGIN表：

=============== 

id 

endTime (nvarchar (150) 

行结束时间：12/31/2020 5： 00 AM

和结果：NaN Days，NaN小时，NaN分钟，NaN秒。

当我将nvarchar（150）的设计更改为datetime时出现错误：无法将类型为“System.DateTime”的对象转换为键入“System.String”。

为什么我得到：NaN Days，NaN Hours，NaN Minutes，NaN Seconds。

问题是什么？谢谢。

Answer 1

要开始，你需要改变

TargetDate = "document.forms[0].auctionEndDate.value"; 

到

TargetDate = document.forms[0].auctionEndDate.value; 

---

什么，我需要做的，以避免错误，当我从nvarchar的类型更改为日期时间？

以猜测在这里，因为我真的不是一个.NET程序员，你需要改变

string tDate = (string)command.ExecuteScalar(); 

到

DateTime tDate = (DateTime) command.ExecuteScalar(); 

You can call GetType() on the return value ExecuteScalar() to see what type it really is.