TreeViewCancelEventArgs.Node 속성

정의

네임스페이스:

System.Windows.Forms

어셈블리:

System.Windows.Forms.dll

확인, 확장명, 축소 또는 선택할 트리 노드를 가져옵니다.

public:
 property System::Windows::Forms::TreeNode ^ Node { System::Windows::Forms::TreeNode ^ get(); };

public System.Windows.Forms.TreeNode? Node { get; }

member this.Node : System.Windows.Forms.TreeNode

Public ReadOnly Property Node As TreeNode

속성 값

TreeNode

확인, 확장, 축소 또는 선택할 TreeNode

예제

다음 예제에서는 축소 상태를 변경 하는 방법에 설명 된 TreeView 선택된 된 노드가 모두 표시 되도록 합니다. 먼저 모든 노드가 축소 되 고 처리기에 추가 됩니다는 TreeView.BeforeExpand 이벤트입니다. 다음에는 모든 노드가 확장 됩니다. TreeView.BeforeExpand 이벤트 처리기를 지정 된 노드에 검사 되는 자식 노드가 있는지 확인 합니다. 노드가 선택 된 자식에 없는 경우 해당 노드에 대 한 확장 취소 됩니다. 노드 옆에 더하기 기호를 클릭 하면 일반 노드를 확장을 허용 하기 위해는 TreeView.BeforeExpand 이벤트 처리기가 제거 합니다.

이 문제를 처리 하 여 구현할 수도 있습니다는 TreeView.BeforeCollapse 이벤트, 해당 항목의 예제에 설명 된 대로 합니다.

전체 예제를 참조 하세요.를 TreeView.CheckBoxes 참조 항목입니다.

private:
   void showCheckedNodesButton_Click( Object^ /*sender*/, EventArgs^ /*e*/ )
   {
      // Disable redrawing of treeView1 to prevent flickering 
      // while changes are made.
      treeView1->BeginUpdate();
      
      // Collapse all nodes of treeView1.
      treeView1->CollapseAll();
      
      // Add the checkForCheckedChildren event handler to the BeforeExpand event.
      treeView1->BeforeExpand += checkForCheckedChildren;
      
      // Expand all nodes of treeView1. Nodes without checked children are 
      // prevented from expanding by the checkForCheckedChildren event handler.
      treeView1->ExpandAll();
      
      // Remove the checkForCheckedChildren event handler from the BeforeExpand 
      // event so manual node expansion will work correctly.
      treeView1->BeforeExpand -= checkForCheckedChildren;
      
      // Enable redrawing of treeView1.
      treeView1->EndUpdate();
   }

   // Prevent expansion of a node that does not have any checked child nodes.
   void CheckForCheckedChildrenHandler( Object^ /*sender*/, TreeViewCancelEventArgs^ e )
   {
      if (  !HasCheckedChildNodes( e->Node ) )
            e->Cancel = true;
   }


   // Returns a value indicating whether the specified 
   // TreeNode has checked child nodes.
   bool HasCheckedChildNodes( TreeNode^ node )
   {
      if ( node->Nodes->Count == 0 )
            return false;

      System::Collections::IEnumerator^ myEnum = node->Nodes->GetEnumerator();
      while ( myEnum->MoveNext() )
      {
         TreeNode^ childNode = safe_cast<TreeNode^>(myEnum->Current);
         if ( childNode->Checked )
                  return true;

         // Recursively check the children of the current child node.
         if ( HasCheckedChildNodes( childNode ) )
                  return true;
      }

      return false;
   }

private void showCheckedNodesButton_Click(object sender, EventArgs e)
{
    // Disable redrawing of treeView1 to prevent flickering 
    // while changes are made.
    treeView1.BeginUpdate();

    // Collapse all nodes of treeView1.
    treeView1.CollapseAll();

    // Add the checkForCheckedChildren event handler to the BeforeExpand event.
    treeView1.BeforeExpand += checkForCheckedChildren;

    // Expand all nodes of treeView1. Nodes without checked children are 
    // prevented from expanding by the checkForCheckedChildren event handler.
    treeView1.ExpandAll();

    // Remove the checkForCheckedChildren event handler from the BeforeExpand 
    // event so manual node expansion will work correctly.
    treeView1.BeforeExpand -= checkForCheckedChildren;

    // Enable redrawing of treeView1.
    treeView1.EndUpdate();
}

// Prevent expansion of a node that does not have any checked child nodes.
private void CheckForCheckedChildrenHandler(object sender, 
    TreeViewCancelEventArgs e)
{
    if (!HasCheckedChildNodes(e.Node)) e.Cancel = true;
}

// Returns a value indicating whether the specified 
// TreeNode has checked child nodes.
private bool HasCheckedChildNodes(TreeNode node)
{
    if (node.Nodes.Count == 0) return false;
    foreach (TreeNode childNode in node.Nodes)
    {
        if (childNode.Checked) return true;
        // Recursively check the children of the current child node.
        if (HasCheckedChildNodes(childNode)) return true;
    }
    return false;
}

Private Sub showCheckedNodesButton_Click(ByVal sender As Object, ByVal e As EventArgs)
    ' Disable redrawing of treeView1 to prevent flickering 
    ' while changes are made.
    treeView1.BeginUpdate()

    ' Collapse all nodes of treeView1.
    treeView1.CollapseAll()

    ' Add the CheckForCheckedChildren event handler to the BeforeExpand event.
    AddHandler treeView1.BeforeExpand, AddressOf CheckForCheckedChildren

    ' Expand all nodes of treeView1. Nodes without checked children are 
    ' prevented from expanding by the checkForCheckedChildren event handler.
    treeView1.ExpandAll()

    ' Remove the checkForCheckedChildren event handler from the BeforeExpand 
    ' event so manual node expansion will work correctly.
    RemoveHandler treeView1.BeforeExpand, AddressOf CheckForCheckedChildren

    ' Enable redrawing of treeView1.
    treeView1.EndUpdate()
End Sub

' Prevent expansion of a node that does not have any checked child nodes.
Private Sub CheckForCheckedChildren(ByVal sender As Object, ByVal e As TreeViewCancelEventArgs)
    If Not HasCheckedChildNodes(e.Node) Then
        e.Cancel = True
    End If
End Sub

' Returns a value indicating whether the specified 
' TreeNode has checked child nodes.
Private Function HasCheckedChildNodes(ByVal node As TreeNode) As Boolean
    If node.Nodes.Count = 0 Then
        Return False
    End If
    Dim childNode As TreeNode
    For Each childNode In node.Nodes
        If childNode.Checked Then
            Return True
        End If
        ' Recursively check the children of the current child node.
        If HasCheckedChildNodes(childNode) Then
            Return True
        End If
    Next childNode
    Return False
End Function 'HasCheckedChildNodes

추가 정보

• TreeNode