VirtualDirectory(String) 建構函式
定義
重要
部分資訊涉及發行前產品,在發行之前可能會有大幅修改。 Microsoft 對此處提供的資訊,不做任何明確或隱含的瑕疵擔保。
初始化 VirtualDirectory 類別的新執行個體。
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)
參數
- virtualPath
- String
這個執行個體所表示之資源的虛擬路徑。
範例
下列程式碼範例是建構函式的實作 VirtualDirectory ,可從 DataSet 自訂 VirtualPathProvider 物件所提供的 物件擷取虛擬檔案資訊。 它包含 GetData
用來填入 VirtualDirectory 實例的方法。 如需執行範例所需的完整程式碼,請參閱類別概觀的 VirtualDirectory 範例一節。
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