问在窗口加载后以编程方式移动列表框中的滚动条

EN

Public Function FindChild(Of T As DependencyObject)(parent As DependencyObject, childName As String) As T
        If parent Is Nothing Then Return Nothing

        Dim foundChild As T = Nothing
        Dim childrenCount As Integer = VisualTreeHelper.GetChildrenCount(parent)

        For i = 0 To childrenCount
            Dim child As DependencyObject
            Try
                child = VisualTreeHelper.GetChild(parent, i)
            Catch ex As Exception
                Continue For
            End Try

            'If the child is not of the request child type child
            Dim childType As T = TryCast(child, T)
            If childType Is Nothing Then
                'recursively drill down the tree
                foundChild = child.FindChild(Of T)(childName)
                'If the child is found, break so we do not overwrite the found child.
                If foundChild IsNot Nothing Then Exit For
            Else
                If Not String.IsNullOrEmpty(childName) Then
                    Dim frameworkElement = TryCast(child, FrameworkElement)
                    'If the child's name is set for search
                    If frameworkElement IsNot Nothing AndAlso frameworkElement.Name = childName Then
                        'if the child's name is of the request name
                        foundChild = TryCast(child, T)
                        Exit For
                    End If
                Else
                    'child element found.
                    foundChild = TryCast(child, T)
                    Exit For
                End If
            End If
        Next
        Return foundChild
    End Function