VirtualPathProvider.GetCacheDependency(String, IEnumerable, DateTime) Método

Definición

Espacio de nombres:

System.Web.Hosting

Ensamblado:

System.Web.dll

Crea una dependencia de caché basada en las rutas de acceso virtuales especificadas.

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

Parámetros

virtualPath

String

Ruta de acceso al recurso virtual primario.

virtualPathDependencies

IEnumerable

Matriz de rutas de acceso a otros recursos que requiere el recurso virtual primario.

utcStart

DateTime

La hora UTC en la que se leyeron los recursos virtuales.

Devoluciones

CacheDependency

Objeto CacheDependency de los recursos virtuales especificados.

Ejemplos

En el ejemplo de código siguiente se implementa el GetCacheDependency método para una clase personalizada VirtualPathProvider . Para obtener el código completo necesario para ejecutar el ejemplo, vea la sección Ejemplo del tema de información general de la VirtualPathProvider clase.

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

Comentarios

La implementación predeterminada del GetCacheDependency método devuelve null. Para almacenar en caché los recursos virtuales para su uso posterior, debe invalidar el GetCacheDependency método o el GetFileHash método .