IHierarchyData 介面
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。
公開階層式資料結構的節點,包括節點物件和描述節點特性的部分屬性。 實作 IHierarchyData 介面的物件可以包含在 IHierarchicalEnumerable 集合中,供 ASP.NET 網站巡覽和資料來源控制項使用。
public interface class IHierarchyData
public interface IHierarchyData
type IHierarchyData = interface
Public Interface IHierarchyData
- 衍生
範例
下列程式碼範例示範如何使用包裝 物件的類別來實 IHierarchyData 作 FileSystemInfo 介面。 類別 FileSystemInfo 是階層式資料節點的良好範例,介面 IHierarchyData 代表階層式資料來源控制項 ASP.NET。 此程式碼範例是針對 類別提供的較大範例的 HierarchicalDataSourceControl 一部分。
public class FileSystemHierarchyData : IHierarchyData
{
private FileSystemInfo fileSystemObject = null;
public FileSystemHierarchyData(FileSystemInfo obj)
{
fileSystemObject = obj;
}
public override string ToString()
{
return fileSystemObject.Name;
}
// IHierarchyData implementation.
public bool HasChildren
{
get
{
if (typeof(DirectoryInfo) == fileSystemObject.GetType())
{
DirectoryInfo temp = (DirectoryInfo)fileSystemObject;
return (temp.GetFileSystemInfos().Length > 0);
}
else
{
return false;
}
}
}
// DirectoryInfo returns the OriginalPath, while FileInfo returns
// a fully qualified path.
public string Path
{
get
{
return fileSystemObject.ToString();
}
}
public object Item
{
get
{
return fileSystemObject;
}
}
public string Type
{
get
{
return "FileSystemData";
}
}
public IHierarchicalEnumerable GetChildren()
{
FileSystemHierarchicalEnumerable children =
new FileSystemHierarchicalEnumerable();
if (typeof(DirectoryInfo) == fileSystemObject.GetType())
{
DirectoryInfo temp = (DirectoryInfo)fileSystemObject;
foreach (FileSystemInfo fsi in temp.GetFileSystemInfos())
{
children.Add(new FileSystemHierarchyData(fsi));
}
}
return children;
}
public IHierarchyData GetParent()
{
FileSystemHierarchicalEnumerable parentContainer =
new FileSystemHierarchicalEnumerable();
if (typeof(DirectoryInfo) == fileSystemObject.GetType())
{
DirectoryInfo temp = (DirectoryInfo)fileSystemObject;
return new FileSystemHierarchyData(temp.Parent);
}
else if (typeof(FileInfo) == fileSystemObject.GetType())
{
FileInfo temp = (FileInfo)fileSystemObject;
return new FileSystemHierarchyData(temp.Directory);
}
// If FileSystemObj is any other kind of FileSystemInfo, ignore it.
return null;
}
}
Public Class FileSystemHierarchyData
Implements IHierarchyData
Public Sub New(ByVal obj As FileSystemInfo)
fileSystemObject = obj
End Sub
Private fileSystemObject As FileSystemInfo = Nothing
Public Overrides Function ToString() As String
Return fileSystemObject.Name
End Function
' IHierarchyData implementation.
Public Overridable ReadOnly Property HasChildren() As Boolean _
Implements IHierarchyData.HasChildren
Get
If GetType(DirectoryInfo) Is fileSystemObject.GetType() Then
Dim temp As DirectoryInfo = _
CType(fileSystemObject, DirectoryInfo)
Return temp.GetFileSystemInfos().Length > 0
Else
Return False
End If
End Get
End Property
' DirectoryInfo returns the OriginalPath, while FileInfo returns
' a fully qualified path.
Public Overridable ReadOnly Property Path() As String _
Implements IHierarchyData.Path
Get
Return fileSystemObject.ToString()
End Get
End Property
Public Overridable ReadOnly Property Item() As Object _
Implements IHierarchyData.Item
Get
Return fileSystemObject
End Get
End Property
Public Overridable ReadOnly Property Type() As String _
Implements IHierarchyData.Type
Get
Return "FileSystemData"
End Get
End Property
Public Overridable Function GetChildren() _
As IHierarchicalEnumerable _
Implements IHierarchyData.GetChildren
Dim children As New FileSystemHierarchicalEnumerable()
If GetType(DirectoryInfo) Is fileSystemObject.GetType() Then
Dim temp As DirectoryInfo = _
CType(fileSystemObject, DirectoryInfo)
Dim fsi As FileSystemInfo
For Each fsi In temp.GetFileSystemInfos()
children.Add(New FileSystemHierarchyData(fsi))
Next fsi
End If
Return children
End Function 'GetChildren
Public Overridable Function GetParent() As IHierarchyData _
Implements IHierarchyData.GetParent
Dim parentContainer As New FileSystemHierarchicalEnumerable()
If GetType(DirectoryInfo) Is fileSystemObject.GetType() Then
Dim temp As DirectoryInfo = _
CType(fileSystemObject, DirectoryInfo)
Return New FileSystemHierarchyData(temp.Parent)
ElseIf GetType(FileInfo) Is fileSystemObject.GetType() Then
Dim temp As FileInfo = CType(fileSystemObject, FileInfo)
Return New FileSystemHierarchyData(temp.Directory)
End If
' If FileSystemObj is any other kind of FileSystemInfo, ignore it.
Return Nothing
End Function 'GetParent
End Class
下列程式碼範例示範如何以遞迴方式逐一 IHierarchicalEnumerable 查看集合、使用 GetHierarchyData 方法從列舉值擷取 IHierarchyData 專案,以及執行資料項目的基本工作。
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="ihd_1.aspx.cs" Inherits="ihd_1_aspx" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>Untitled Page</title>
</head>
<body>
<form id="form1" runat="server">
<div>
</div>
</form>
</body>
</html>
<%@ Page Language="VB" AutoEventWireup="true" CodeFile="ihd_1.aspx.vb" Inherits="ihd_1_aspx" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>Untitled Page</title>
</head>
<body>
<form id="form1" runat="server">
<div>
</div>
</form>
</body>
</html>
備註
IHierarchyData介面是由類別實作,這些類別代表階層式結構的節點,並追蹤其父節點和子節點的階層式關聯性。 實作 介面的 IHierarchyData 類別可以包含在實作 介面的 IHierarchicalEnumerable 集合中。
屬性
HasChildren |
指出 IHierarchyData 物件所表示的階層式資料節點是否有任何子節點。 |
Item |
取得 IHierarchyData 物件所表示的階層式資料節點。 |
Path |
取得節點的階層式路徑。 |
Type |
方法
GetChildren() |
取得列舉物件,表示目前階層式節點的所有子節點。 |
GetParent() |
取得 IHierarchyData 物件,表示目前階層式節點的父節點。 |