Defines the default cache policy for all FTP requests.
Public Shared Property DefaultCachePolicy As RequestCachePolicy
public static RequestCachePolicy DefaultCachePolicy { get; set; }
public: static property RequestCachePolicy^ DefaultCachePolicy { RequestCachePolicy^ get (); void set (RequestCachePolicy^ value); }
static member DefaultCachePolicy : RequestCachePolicy with get, set
The caller tried to set this property to nullNothingnullptra null reference (Nothing in Visual Basic).
Only content received using the DownloadFile command is cached.
The following table describes the effects of FTP caching policies on FtpWebRequest.
Policy
Effect
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; otherwise, throws a WebException.
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 time stamp of the resource on the server; otherwise, the resource is downloaded from the server, stored in the cache, and 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.
Setting DefaultCachePolicy overrides any configuration setting.
Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2