VirtualDirectory(String) Konstruktor

Definition

Namespace:

System.Web.Hosting

Assembly:

System.Web.dll

Initialisiert eine neue Instanz der VirtualDirectory-Klasse.

protected:
 VirtualDirectory(System::String ^ virtualPath);

protected VirtualDirectory (string virtualPath);

new System.Web.Hosting.VirtualDirectory : string -> System.Web.Hosting.VirtualDirectory

Protected Sub New (virtualPath As String)

Parameter

virtualPath

String

Der virtuelle Pfad zu der durch diese Instanz dargestellten Ressource.

Beispiele

Das folgende Codebeispiel ist eine Implementierung des Konstruktors, der VirtualDirectory virtuelle Dateiinformationen aus einem Objekt abruft, das von einem DataSet benutzerdefinierten VirtualPathProvider Objekt bereitgestellt wird. Es enthält die Methode, die GetData zum Auffüllen der VirtualDirectory Instanz verwendet wird. Den vollständigen Code, der zum Ausführen des Beispiels erforderlich ist, finden Sie im Abschnitt "Beispiel" der VirtualDirectory Klassenübersicht.

public SampleVirtualDirectory(string virtualDir, SamplePathProvider provider)
  : base(virtualDir)
{
  spp = provider;
  GetData();
}

protected void GetData()
{
  DataSet ds = spp.GetVirtualData();

  // Clean up the path to match data in resource file.
  string path = VirtualPath.Replace(HostingEnvironment.ApplicationVirtualPath, "");
  path = path.TrimEnd('/');

  // Get the virtual directory from the resource table.
  DataTable dirs = ds.Tables["resource"];
  DataRow[] rows = dirs.Select(
    String.Format("(name = '{0}') AND (type='dir')", path));

  // If the select returned a row, the directory exists.
  if (rows.Length > 0)
  {
    exists = true;

    // Get children from the resource table.
    // This technique works for small numbers of virtual resources.
    //   Sites with moderate to large numbers of virtual
    //   resources should choose a method that consumes fewer
    //   computer resources.
    DataRow[] childRows = dirs.Select(
      String.Format("parentPath = '{0}'", path));

    foreach (DataRow childRow in childRows)
    {
      string childPath = (string)childRow["path"];

      if (childRow["type"].ToString() == "dir")
      {
        SampleVirtualDirectory svd = new SampleVirtualDirectory(childPath, spp);
        children.Add(svd);
        directories.Add(svd);
      }
      else
      {
        SampleVirtualFile svf = new SampleVirtualFile(childPath, spp);
        children.Add(svf);
        files.Add(svf);
      }
    }
  }
}

Public Sub New(ByVal virtualDir As String, ByVal provider As SamplePathProvider)
  MyBase.New(virtualDir)
  spp = provider
  GetData()
End Sub

Protected Sub GetData()
  ' Get the data from the SamplePathProvider.
  Dim spp As SamplePathProvider
  spp = CType(HostingEnvironment.VirtualPathProvider, SamplePathProvider)

  Dim ds As DataSet
  ds = spp.GetVirtualData

  ' Clean up the path to match data in resource file.
  Dim path As String
  path = VirtualPath.Replace(HostingEnvironment.ApplicationVirtualPath, "")
  Dim trimChars() As Char = {"/"c}
  path = path.TrimEnd(trimChars)

  ' Get the virtual directory from the resource table.
  Dim dirs As DataTable
  dirs = ds.Tables("resource")
  Dim rows As DataRow()
  rows = dirs.Select( _
    String.Format("(name = '{0}') AND (type='dir')", path))

  ' If the select returned a row, the directory exits.
  If (rows.Length > 0) Then
    existsValue = True

    ' Get the children from the resource table.
    ' This technique works for small numbers of virtual resources.
    '  Sites with moderate to large numbers of virtual
    '  resources should choose a method that consumes fewer
    '  computer resources.
    Dim childRows As DataRow()
    childRows = dirs.Select( _
      String.Format("parentPath = '{0}'", path))

    For Each childRow As DataRow In childRows
      Dim childPath As String
      childPath = CType(childRow("path"), String)

      If (childRow("type").ToString = "dir") Then
        Dim svd As New SampleVirtualDirectory(childPath, spp)
        childrenValue.Add(svd)
        directoriesValue.Add(svd)
      Else
        Dim svf As New SampleVirtualFile(childPath, spp)
        childrenValue.Add(svf)
        directoriesValue.Add(svf)
      End If
    Next

  End If
End Sub

Siehe auch

• VirtualFile