ASP.NET网页-使用脚本显示由预定义的日期和时间指示的图像/文本

Question

My goal is to display a string or image on a ASP.NET webpage only during a predefined date and time (Monday through Friday, 9:00AM-5:00PM). Keep in mind, I will be relying on fixed server time, PST.

I am not sure whether to use jQuery, JavaScript, C# or PHP for the script. Here is what I have come up with so far in JavaScript. Am I on the right path?

<script type="text/javascript" language="javascript">
function GetDateTime()
{
var d = new Date();
var day = d.getDay(); //returns 0-6 corresponding to Sunday through Saturday
var hour = d.getHours(); //returns 0-23 corresponding to hours 
}   
</script>

Now I need help manipulating the variables 'day' and 'hour'. I came up with a generic algorithm to specify Monday through Friday, 9:00AM - 5:00PM as follows:

if ((day>0 && day<6) && (hour>8 && hour<18) ) //days 1 through 5 (M-F) and (hours 9:00-17:00)
{ alert("testing") 
//This is for testing purposes. I will eventually insert code here to display string or image perhaps? 
}

Assuming the date and time are properly obtained and the if statement algorithm is correct, how do I implement the Javascript portion and "tie the code together" with my ASP.NET page to display a string or image based on those parameters?

This is my first time posting on Stackoverflow. I hope I am addressing this question properly and clearly enogh. Thanks in advance for any help.

---

Edit: I gave up on JavaScript for now. C# seems to me like the proper way of doing this. Thanks to codingbiz 's resonse, I was able to implement the script as shown below:

<script runat="server">

protected void Page_Load(object sender, EventArgs e)
{
    DateTime thisTime = DateTime.Now;           // retrieve date and time
    string day = thisTime.DayOfWeek.ToString(); // declare and define day to string 
    int hour = thisTime.Hour;                   // declare and define hour to int

//check if string contains the following: "Monday,Tuesday,Wednesday,Thursay,Friday"
if ("Monday,Tuesday,Wednesday,Thursay,Friday".IndexOf(day) > -1 && hour >= 9 && hour <= 17)
{
   conditionalLabel.Text = "<img src='sony_frontex3_repair.jpg' />";
}
}
</script>

I also added the following conditional label to the body of the content page and master page:

New question: Lets say a user visits my website at 4:45PM and the image/string displays as intended. Some time goes by and it is now 5:05. Will the image/string automatically disappear, or only after the page is closed, then reopened? Will cookies or cache affect the performance of this script? Is there any such issues I need to address, such as specifying in the code to automatically refresh the page?

Answer 1

You can make use of Hidden field in the aspx page. Load the required string value from code behind into the hidden field and then make use of that field in the javascript function to display the value.

Answer 2

It is easy to do with ASP.NET and C#. You can also do it using JavaScript but I won't recommend it as you will be dealing with client's date and time. To show it using ASP.net you may take advantage of an ASP.net control called PlaceHolder . You can easily put controls or a simple text or even an HTML markup inside a PlaceHolder. It's been a while since I wrote ASP.net WebForms so excuse me if there is any problems with my code but it shows you the general idea. Put

<asp:PlaceHolder Id="MessageHolder" runat="Server" />

in your .aspx page and in the C# code at the page load event put something like this

void Page_Load(...) {
   if (DateTime.Now > StartDate && DateTime.Now < EndDate) {
      MessageHolder.Controls.Add(...);
   }
}

If you simply want to add HTML tags inside and not ASP.net controls you can use a class called HtmlGenericControl to generate your HTML tags and then add them inside the PlaceHolder.

If you want to put a text in your page at that specific time instead of using PlaceHolder you might use Literal control and simply say:

LiteralControl.Text = "<p>My special message!</p>";

Regards,
Shakib