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ASP.NET data cache scheme is how, many novices are not very clear about this, in order to help you solve this problem, the following editor will explain for you in detail, people with this need can come to learn, I hope you can gain something.

ASP.NET data cache.

Friends who have come into contact with asp.net version 1.x may say that this is not a new thing.

Yes, ASP.NET data caching is not a new product of asp.net 2.0, but asp.net 2.0 gives data caching more properties and methods, making it possible for data caching to flourish in the asp.net 2.0 era.

The data cache stores frequently requested content in the server-side cache, so that these contents can respond more quickly when they are requested again, and effectively reduce the resource consumption of the server and improve the running performance of the program.

Asp.net 2.0 supports the following caching schemes:

1. Page output ASP.NET data cache

Page output caching is a relatively simple caching mechanism at the traditional level. It caches the page data in the server memory, and when a client requests these contents again, the server can output the page data directly until the data cache expires.

There are two ways to use the page output cache:

Using the @ OutputCache directive, common code such as:

<% @ OutputCache Duration= "60" VaryByParam= "sID" Location= "Any" >

The above example defines that the valid time of the page output cache is 60 seconds after creating a new cache; the cache version varies according to the sID parameters passed on the page; Location= "Any" specifies.

Use the page output cache API. This method is executed in the program part of the page. Common code is as follows:

Response.Cache.SetExpires (DataTime.Now.AddSeconds (60))

The previous sentence sets the validity time of the page cache to 60s.

There are many more properties about the page output cache, and only the commonly used ones are introduced here. For more information, please see: http://www.itgao.com/html/2007-04/19811.html

2. Partial caching of pages

Sometimes we may not want to cache the entire page, but just a part of the page. There are three common methods:

Use the @ OutputCache instruction

The essence of this method is to make this part of the content that needs to be cached into a user-defined control, and then set the page cache code for the custom control, the same as the page output cache.

Use the PartialCachingAttribute class

This method sets the cache configuration of the control in the code-behind file of the user control as follows

PartialCaching (20)] public partial class NewUserControl:UserControl {. }

Use the ControlCachePolicy class

The following considerations apply to using the ControlCachePolicy class.

One is that if you want to create a correct and valid instance of the ControlCachePolicy class to set up the control cache

Then you must access the BasePartialCachingControl.CachePolicy property of the PartialCachingControl class (BasePartialCachingControl is the base class of the PartialCachingControl class).

Second, the ControlCachePolicy instance can operate successfully only between the Init and PreRender phases of the control life cycle.

Example code:

Use the PartialCachingAttribute class to set up the user control cache (user control code-behind file) [PartialCaching] public partial class SimpleControl: UserControl {.} ASP.NET page file source code. Use the ControlCachePolicy class to set up the user control cache (ASP.NET page file) <% @ Page Language= "C#" Debug= "true"% > <% @ Reference Control= "SimpleControl.ascx"% > < script language= "C#" runat= "server" > void Page_Init (object sender, System.EventArgs e) {/ / dynamically load the user control and return the PartialCachingControl instance object PartialCachingControl pcc = LoadControl ("SimpleControl.ascx") as PartialCachingControl / / get ControlCachePolicy instance ControlCachePolicy cacheSettings = pcc.CachePolicy; / / if the cache expiration setting of the user control is greater than 60 seconds, set the new expiration time to 30 seconds and set it to the absolute expiration policy if (cacheSettings.Duration > TimeSpan.FromSeconds (60)) {/ / set the user control expiration time and cache expiration policy cacheSettings.SetExpires (DateTime.Now.Add (TimeSpan.FromSeconds (30)) CacheSettings.SetSlidingExpiration (false);} / / add user controls to the page control hierarchy Controls.Add (pcc);} < / script >

3. Application data caching

The main function of ASP.NET data cache is to store a variety of application-related objects in memory. There are three ways:

Specify keys and values

Cache ["keyName"] = "123"

This statement creates or rewrites the cache named txtName and assigns a value of 123.

Use the Add method

Cache.Add ("keyName", "123", null,DataTime. Now.AddSeconds (60), TimeSpan.Zero, CacheItemPriority.High,onRemove)

This sentence implements the same function as the above example, and sets its cache dependency as the null; cache validity time is 60s. The interval between the expiration time of the added object and the added object is zero (TimeSpan.Zero); the priority of the cache object is High;. When the cache is deleted, the delegate name is called onRemove.

Use the Insert method

The Insert method is basically the same as the Add method, but the Insert method also has several overloaded methods of its own, such as:

Cache.Insert ("keyName", "123")

4. Cache dependency

ASP.NET data caching has many advantages, but it also has disadvantages. For example, the real-time data, the page obtained by the user may be dozens of seconds or even a few hours ago the server cache information, which is intolerable for real-time programs. At this time, we can determine whether the program needs to rebuild (refresh) the cache by setting the cache dependency and judging the changes of the dependent files.

There are many ways to rely on caching. Here we focus on custom dependency caching: custom cache dependencies

Code:

String fileName = Server.MapPath ("file.xml"); / / set the file path DateTime dt = DateTime.Now; / / set the start time of tracking dependent files CacheDependency dep = new CacheDependency (fileName,dt); / / does it help you to create dependent objects after reading the above? If you want to know more about the relevant knowledge or read more related articles, please follow the industry information channel, thank you for your support.

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