IHierarchyData Gränssnitt

Definition

public interface class IHierarchyData

public interface IHierarchyData

type IHierarchyData = interface

Public Interface IHierarchyData

Härledda

System.Web.SiteMapNode

Exempel

Följande kodexempel visar hur du implementerar IHierarchyData gränssnittet med en klass som omsluter ett FileSystemInfo objekt. Klassen FileSystemInfo är ett bra exempel på en hierarkisk datanod, som gränssnittet IHierarchyData representerar för ASP.NET hierarkiska datakällkontroller. Det här kodexemplet är en del av ett större exempel för HierarchicalDataSourceControl klassen.

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

Följande kodexempel visar hur du rekursivt itererar genom en IHierarchicalEnumerable samling, extraherar IHierarchyData objektet från uppräknaren GetHierarchyData med hjälp av metoden och utför grundläggande arbete med dataobjektet.

<%@ 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>

Kommentarer

Gränssnittet IHierarchyData implementeras av klasser som representerar noder i en hierarkisk struktur och spårar de hierarkiska relationerna till sina överordnade och underordnade noder. Klasser som implementerar IHierarchyData gränssnittet kan finnas i samlingar som implementerar IHierarchicalEnumerable gränssnittet.

Se även

• IHierarchicalEnumerable
• SiteMapNode