Beginning Ajax With ASP.NET (2006).pdf

Chapter 10
New Time:
In the preceding code, on a button click, two remote calls are made out to the server — a call to the
GetServerCachedTime method and one to the GetServerCurrentTime method. The GetServer
CachedTime method on the server returns the current server time when it is called the first time. The
result of this call is cached in server memory. Subsequent calls are returned the cached result for the next
100 seconds, at which point the next request will generate a new time and a new entry in the server cache.
As a result, calls to GetServercurrentTime() will result in the current time of the server being
returned while calls to GetServerCachedTime() will result in a value that is up to 100 seconds old.
The following is the code for a web service:
[WebMethod(CacheDuration = 100)]
public DateTime GetServerCachedTime()
{
return(DateTime.Now.ToUniversalTime());
}
[WebMethod]
public DateTime GetServerCurrentTime()
{
return (DateTime.Now.ToUniversalTime());
}
Atlas uses UTC encoding for dates and time. This may create confusion for you if you don’t remember
it. Personally, my system is set with the time of GMT – 5. As a result, the times that were coming back
were 5 hours off.
Figure 10-7 shows the results of multiple calls to the cached and noncached web services.
In Figure 10-7, you will notice the two different time values. This shows that calling the cached web service
returns the cached value and the noncached version returns the current value of the DateTime.Now
object.
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