HttpRequestCachePolicy Class
Defines an application's caching requirements for resources obtained by using HttpWebRequest objects.
Namespace: System.Net.Cache
Assembly: System (in System.dll)
The HttpRequestCachePolicy type exposes the following members.
| Name | Description | |
|---|---|---|
 | HttpRequestCachePolicy() | Initializes a new instance of the HttpRequestCachePolicy class. |
| HttpRequestCachePolicy(DateTime) | Initializes a new instance of the HttpRequestCachePolicy class using the specified cache synchronization date. |
| HttpRequestCachePolicy(HttpRequestCacheLevel) | Initializes a new instance of the HttpRequestCachePolicy class using the specified cache policy. |
| HttpRequestCachePolicy(HttpCacheAgeControl, TimeSpan) | Initializes a new instance of the HttpRequestCachePolicy class using the specified age control and time values. |
| HttpRequestCachePolicy(HttpCacheAgeControl, TimeSpan, TimeSpan) | Initializes a new instance of the HttpRequestCachePolicy class using the specified maximum age, age control value, and time value. |
| HttpRequestCachePolicy(HttpCacheAgeControl, TimeSpan, TimeSpan, DateTime) | Initializes a new instance of the HttpRequestCachePolicy class using the specified maximum age, age control value, time value, and cache synchronization date. |
| Name | Description | |
|---|---|---|
| CacheSyncDate | Gets the cache synchronization date for this instance. |
| Level | Gets the HttpRequestCacheLevel value that was specified when this instance was created. |
| MaxAge | Gets the maximum age permitted for a resource returned from the cache. |
| MaxStale | Gets the maximum staleness value that is permitted for a resource returned from the cache. |
| MinFresh | Gets the minimum freshness that is permitted for a resource returned from the cache. |
| Name | Description | |
|---|---|---|
| Equals(Object) | Determines whether the specified object is equal to the current object. (Inherited from Object.) |
| Finalize | Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.) |
| GetHashCode | Serves as a hash function for a particular type. (Inherited from Object.) |
| GetType | Gets the Type of the current instance. (Inherited from Object.) |
| MemberwiseClone | Creates a shallow copy of the current Object. (Inherited from Object.) |
| ToString | Returns a string representation of this instance. (Overrides RequestCachePolicy.ToString().) |
You can specify a default cache policy for your application by using the DefaultCachePolicy property or the application or machine configuration files. For more information, see <requestCaching> Element (Network Settings).
You can specify the cache policy for an individual request by using the CachePolicy property.
Caching for Web services is not supported.
The following code example creates a default cache policy for the application domain, and overrides it for a request.
// The following method demonstrates overriding the // caching policy for a request. public static WebResponse GetResponseNoCache(Uri uri) { // Set a default policy level for the "http:" and "https" schemes. HttpRequestCachePolicy policy = new HttpRequestCachePolicy(HttpRequestCacheLevel.Default); HttpWebRequest.DefaultCachePolicy = policy; // Create the request. WebRequest request = WebRequest.Create(uri); // Define a cache policy for this request only. HttpRequestCachePolicy noCachePolicy = new HttpRequestCachePolicy(HttpRequestCacheLevel.NoCacheNoStore); request.CachePolicy = noCachePolicy; WebResponse response = request.GetResponse(); Console.WriteLine("IsFromCache? {0}", response.IsFromCache); return response; }
Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
