VirtualDirectory(String) 构造函数

定义

命名空间:

System.Web.Hosting

程序集:

System.Web.dll

初始化 VirtualDirectory 类的新实例。

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)

参数

virtualPath

String

此实例所表示资源的虚拟路径。

示例

下面的代码示例是构造函数的 VirtualDirectory 实现，该构造函数从 DataSet 自定义 VirtualPathProvider 对象提供的对象检索虚拟文件信息。 它包括 GetData 用于填充 VirtualDirectory 实例的方法。 有关运行示例所需的完整代码，请参阅类概述的示例 VirtualDirectory 部分。

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

另请参阅

• VirtualFile