<requestCaching> Element (Network Settings)

發行項
12/13/2007

Controls the caching mechanism for network requests.

<requestCaching
  isPrivateCache ="true|false"
  disableAllCaching="true|false"
  defaultPolicyLevel="BypassCache|Default|CacheOnly|CacheIfAvailable|Revalidate|Reload|NoCacheNoStore|Revalidate"
  unspecifiedMaximumAge= "d.hh.mm.ss""
  <defaultHttpCachePolicy> … </defaultHttpCachePolicy>
  <defaultFtpCachePolicy> … </defaultFtpCachePolicy>
/>

Attributes and Elements

The following sections describe attributes, child elements, and parent elements.

Attributes

Attribute	Description
isPrivateCache	Specifies whether the cache provides isolation between the information of different users. The default value is true. This value should be false for middle tier applications.
disableAllCaching	Specifies that caching is disabled for all Web responses, and cannot be overridden programmatically.
defaultPolicyLevel	One of the values in the RequestCacheLevel enumeration. The default value is BypassCache.
unspecifiedMaximumAge	Specifies the default time after which content is marked as expired.

policyLevel Attribute

Value	Description
Default	Returns the cached resource if the resource is fresh, the content length is accurate, and the expiration, modification, and content length attributes are present.
BypassCache	Returns the resource from the server.
CacheOnly	Returns the cached resource if the content length is present and matches the entry size.
CacheIfAvailable	Returns the cached resource if the content length is provided and matches the entry size; otherwise, the resource is downloaded from the server and is returned to the caller.
Revalidate	Returns the cached resource if the timestamp of the cached resource is the same as the timestamp of the resource on the server; otherwise, the resource is downloaded from the server, stored in the cache, and is returned to the caller.
Reload	Downloads the resource from the server, stores it in the cache, and returns the resource to the caller.
NoCacheNoStore	If a cached resource exists, it is deleted. The resource is downloaded from the server and is returned to the caller.
Revalidate	Satisfies a request by using the cached copy of the resource if the timestamp is the same as the timestamp of the resource on the server; otherwise, the resource is downloaded from the server, presented to the caller, and is stored in the cache,

Child Elements

Element	Description
defaultHttpCachePolicy	Optional element. Describes whether HTTP caching is active and describes the default caching policy.
<defaultFtpCachePolicy> Element (Network Settings)	Optional element. Describes whether FTP caching is active and describes the default caching policy.

defaultHttpCachePolicy

Optional element.

Describes whether HTTP caching is active and describes the default caching policy.

<defaultFtpCachePolicy> Element (Network Settings)

Optional element.

Describes whether FTP caching is active and describes the default caching policy.

Parent Elements

Element	Description
system.net	Contains settings that specify how the .NET Framework connects to the network.

Example

The following code example shows how to disable all caching.

<configuration>
  <system.net>
    <requestCaching
      disableAllCaching="true"
    />
  </system.net>
</configuration>

共用方式為