VirtualPathProvider.GetCacheDependency(String, IEnumerable, DateTime) Metod

Definition

Namnområde:
System.Web.Hosting
Sammansättning:
System.Web.dll

Skapar ett cacheberoende baserat på de angivna virtuella sökvägarna.

public:
 virtual System::Web::Caching::CacheDependency ^ GetCacheDependency(System::String ^ virtualPath, System::Collections::IEnumerable ^ virtualPathDependencies, DateTime utcStart);
public virtual System.Web.Caching.CacheDependency GetCacheDependency(string virtualPath, System.Collections.IEnumerable virtualPathDependencies, DateTime utcStart);
abstract member GetCacheDependency : string * System.Collections.IEnumerable * DateTime -> System.Web.Caching.CacheDependency
override this.GetCacheDependency : string * System.Collections.IEnumerable * DateTime -> System.Web.Caching.CacheDependency
Public Overridable Function GetCacheDependency (virtualPath As String, virtualPathDependencies As IEnumerable, utcStart As DateTime) As CacheDependency

Parametrar

virtualPath
String

Sökvägen till den primära virtuella resursen.

virtualPathDependencies
IEnumerable

En matris med sökvägar till andra resurser som krävs av den primära virtuella resursen.

utcStart
DateTime

UTC-tiden då de virtuella resurserna lästes.

Returer

CacheDependency

Ett CacheDependency objekt för de angivna virtuella resurserna.

Exempel

I följande kodexempel implementeras GetCacheDependency metoden för en anpassad VirtualPathProvider klass. Fullständig kod som krävs för att köra exemplet finns i avsnittet Exempel i VirtualPathProvider avsnittet klassöversikt.

public override CacheDependency GetCacheDependency(
  string virtualPath, 
  System.Collections.IEnumerable virtualPathDependencies, 
  DateTime utcStart)
{
  if (IsPathVirtual(virtualPath))
  {
    System.Collections.Specialized.StringCollection fullPathDependencies = null;

    // Get the full path to all dependencies.
    foreach (string virtualDependency in virtualPathDependencies)
    {
      if (fullPathDependencies == null)
        fullPathDependencies = new System.Collections.Specialized.StringCollection();

      fullPathDependencies.Add(virtualDependency);
    }
    if (fullPathDependencies == null)
      return null;

    // Copy the list of full-path dependencies into an array.
    string[] fullPathDependenciesArray = new string[fullPathDependencies.Count];
    fullPathDependencies.CopyTo(fullPathDependenciesArray, 0);
    // Copy the virtual path into an array.
    string[] virtualPathArray = new string[1];
    virtualPathArray[0] = virtualPath;

    return new CacheDependency(virtualPathArray, fullPathDependenciesArray, utcStart);
  }
  else
        {
            return Previous.GetCacheDependency(virtualPath, virtualPathDependencies, utcStart);
        }
    }

Public Overrides Function GetCacheDependency(ByVal virtualPath As String, ByVal virtualPathDependencies As IEnumerable, ByVal utcStart As Date) As CacheDependency
  If (IsPathVirtual(virtualPath)) Then

    Dim fullPathDependencies As System.Collections.Specialized.StringCollection
    fullPathDependencies = Nothing

    ' Get the full path to all dependencies.
    For Each virtualDependency As String In virtualPathDependencies
      If fullPathDependencies Is Nothing Then
        fullPathDependencies = New System.Collections.Specialized.StringCollection
      End If

      fullPathDependencies.Add(virtualDependency)
    Next

    If fullPathDependencies Is Nothing Then
      Return Nothing
    End If

    Dim fullPathDependenciesArray As String()
    fullPathDependencies.CopyTo(fullPathDependenciesArray, 0)

    Return New CacheDependency(fullPathDependenciesArray, utcStart)
  Else
    Return Previous.GetCacheDependency(virtualPath, virtualPathDependencies, utcStart)
  End If
End Function

Kommentarer

Standardimplementeringen GetCacheDependency av metoden returnerar null. Om du vill cachelagrat virtuella resurser för senare användning måste du åsidosätta antingen GetCacheDependency -metoden eller GetFileHash -metoden.

Gäller för