バージョン

LastEnteredElement プロパティ

マウスが入った最後の要素を返します。マウスがどの要素上も移動していない場合はnullを返します。
シンタックス
'宣言
 
Public ReadOnly Property LastEnteredElement As Infragistics.Win.UIElement
public Infragistics.Win.UIElement LastEnteredElement {get;}
使用例
Imports Infragistics.Shared
Imports Infragistics.Win
Imports Infragistics.Win.UltraWinDock

Private Sub ultraDockManager1_DoubleClickSplitterBar(ByVal sender As Object, ByVal e As Infragistics.Win.UltraWinDock.PanesEventArgs) Handles ultraDockManager1.DoubleClickSplitterBar

    ' This event will fire if you double click the splitter
    ' bar adjacent to a dock area pane or a splitter bar
    ' between two horizontally or vertically split panes
    '

    If (e.Panes.Length = 1 AndAlso TypeOf e.Panes(0) Is DockAreaPane) Then
        Dim dockArea As DockAreaPane = CType(e.Panes(0), DockAreaPane)

        ' Since this could happen while a drag of the splitter
        ' bar is pending, cancel the drag first
        If (Not Me.ultraDockManager1.LastEnteredElement Is Nothing) Then
            Me.ultraDockManager1.LastEnteredElement.ControlElement.TerminateCapture()
        End If

        Select Case dockArea.DockedLocation
            Case DockedLocation.DockedLeft, DockedLocation.DockedRight
                ' reset the width to a default width but
                ' keep the current height info
                dockArea.Size = New Size(100, dockArea.Size.Height)
            Case DockedLocation.DockedTop, DockedLocation.DockedBottom
                ' reset the height to a default width but
                ' keep the current width info
                dockArea.Size = New Size(dockArea.Size.Width, 100)
        End Select
    End If

End Sub
using Infragistics.Shared;
using Infragistics.Win;
using Infragistics.Win.UltraWinDock;
using System.Diagnostics;

private void ultraDockManager1_DoubleClickSplitterBar(object sender, Infragistics.Win.UltraWinDock.PanesEventArgs e)
{

	// This event will fire if you double click the splitter
	// bar adjacent to a dock area pane or a splitter bar
	// between two horizontally or vertically split panes
	//

	if (e.Panes.Length == 1 && e.Panes[0] is DockAreaPane)
	{
		DockAreaPane dockArea = e.Panes[0] as DockAreaPane;

		// Since this could happen while a drag of the splitter
		// bar is pending, cancel the drag first
		if (this.ultraDockManager1.LastEnteredElement != null)
			this.ultraDockManager1.LastEnteredElement.ControlElement.TerminateCapture();

		switch (dockArea.DockedLocation)
		{
			case DockedLocation.DockedLeft:
			case DockedLocation.DockedRight:
				// Reset the width to a default width but
				// keep the current height info
				dockArea.Size = new Size(100, dockArea.Size.Height);
				break;
			case DockedLocation.DockedTop:
			case DockedLocation.DockedBottom:
				// Reset the height to a default width but
				// keep the current width info
				dockArea.Size = new Size(dockArea.Size.Width, 100);
				break;
		}
	}
}
参照