ASP. NET data cache

Note: This article is from the network.
What is ASP. NET data cache learning? How to use ASP. NET data cache? Before talking about ASP. NET data caching, you should first talk about using parameter caching on the page. As mentioned earlier, cache settings Varybyparam = "NONE" If there is no parameter, you can also set varybyparam. The set parameter corresponds to the query string value sent with the get method attribute, or to the parameter sent using the POST method. When this attribute is set to multiple parameters, the output cache contains a different version of the Request Document for each specified parameter combination. Possible Value Including none, asterisks (*), and any valid query string or post parameter names . Simply put, it is set to the querystring name we use on the page.
Let's look at an example:
< % @ Page Language = " C # " Autoeventwireup = " True " Codefile = " Date. aspx. CS " Inherits = " Date " % >
< % @ Outputcache duration = " 60 " Varybyparam = " Customerid " % >

<Asp: hyperlink ID = " Hyperlink1 " Runat = " Server " Navigateurl = " ~ /Date. aspx? Cu Stomerid = 16 " > 16 < / ASP: hyperlink>
<Asp: hyperlink ID = " Hyperlink2 " Runat = " Server " Navigateurl = " ~ /Date. aspx? Cu Stomerid = 19 " > 19 < / ASP: hyperlink>
Click "16" and "19" respectively after the operation to select different data based on the two keywords. At this time, two cache pages will be created based on the two parameters we passed, remember the displayed time after each keyword is clicked, and refresh it repeatedly to see if the time has changed! Now let's talk about data caching.

ASP. NET data cache (data caching)

In the system. Web. caching namespace, there is a class "cache". We can cache data through this class.

The simplest cache method is cache ["mycachestring"] = "My csdn blog !!! "; Create a cache by assigning values, and then retrieve the cache by assigning values: mylabel. TEXT = cache ["mycachestring"]. tostring (); this method is very simple to use, but the function is limited, in orderThe cache. insert () method should be used for better cache customization.For example:

You only need to put the gridview in the page.

ASP. NET data cache parameter description

Cache. insert (string, object, cachedependency, datetime, timespan) 1 is the cache name, 2 is the cached data object, 3 is the cache key dependency, usually null, 4 is the expiration time. If the relative expiration time is used, it is set to noabsoluteexpiration, and 5 is the adjustable expiration time. If parameter 4 uses a fixed expiration time, this parameter must be set to noslidingexpiration. Oh, isn't it a bit dizzy? Here are two examples to illustrate the expiration time problem.

Cache. insert ("ds", DV, null, datetime. Now. addminutes (5), system. Web. caching. cache. noslidingexpiration );
In this exampleAfter the cache is created, it will expire in 5 minutes.
Cache. insert ("ds", DV, null, system. Web. caching. cache. noabsoluteexpiration, timespan. fromminutes (5 ));

In this example, after the cache is created,The expiration time is adjustable.For example, the cache expiration time set for seconds should be, but if someone accesses the cache at, the expiration time will be adjusted to, and so on ......

Let's create a test in vs2005 to check the performance changes before and after cache usage! No. It took 0.43 seconds before the cache was completed, and 0.08 seconds after the cache was used, the performance was more than 5 times different !!!