IHierarchyData.GetParent 方法

定義

命名空間:

System.Web.UI

組件:

System.Web.dll

取得 IHierarchyData 物件，表示目前階層式節點的父節點。

public:
 System::Web::UI::IHierarchyData ^ GetParent();

public System.Web.UI.IHierarchyData GetParent ();

abstract member GetParent : unit -> System.Web.UI.IHierarchyData

Public Function GetParent () As IHierarchyData

傳回

IHierarchyData

IHierarchyData 物件，表示目前階層式節點的父節點。

範例

下列程式碼範例示範如何在實作 介面的類別中實 GetParent 作 IHierarchyData 方法。 類別會 FileSystemHierarchyData FileSystemInfo 包裝 物件，而 GetParent 方法實作會檢查 物件的類型 FileSystemInfo ，並根據類型傳回適當的父物件。 此程式碼範例是介面和 HierarchicalDataSourceControl 類別所提供較大範例的 IHierarchyData 一部分。

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 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

備註

介面 IHierarchyData 未定義 HasParent 便利屬性，因此呼叫端必須檢查 方法 null 的 GetParent 傳回值，以判斷目前 IHierarchyData 節點是否為節點所屬階層式資料結構的根節點。

另請參閱

• GetChildren()
• HasChildren