TreeView.AfterCheck TreeView.AfterCheck TreeView.AfterCheck TreeView.AfterCheck Event

定義

ツリー ノードのチェック ボックスがオンにされた後に発生します。Occurs after the tree node check box is checked.

public:
 event System::Windows::Forms::TreeViewEventHandler ^ AfterCheck;
public event System.Windows.Forms.TreeViewEventHandler AfterCheck;
member this.AfterCheck : System.Windows.Forms.TreeViewEventHandler 
Public Custom Event AfterCheck As TreeViewEventHandler 

次のコード例では、ユーザーがチェックされTreeNodeた状態を変更したときに、のすべての子ツリーノードを更新します。The following code example updates all the child tree nodes of a TreeNode when the user changes its checked state. このFormコードでTreeView は、TreeNodeにオブジェクトを含むを持つが必要です。 TreeNodeCollectionThis code requires that you have a Form with a TreeView that has TreeNode objects in its TreeNodeCollection. TreeNodeCollectionは、子ノードを持つツリーノードが必要です。The TreeNodeCollection should have tree nodes with child nodes.

// Updates all child tree nodes recursively.
void CheckAllChildNodes( TreeNode^ treeNode, bool nodeChecked )
{
   IEnumerator^ myEnum = treeNode->Nodes->GetEnumerator();
   while ( myEnum->MoveNext() )
   {
      TreeNode^ node = safe_cast<TreeNode^>(myEnum->Current);
      node->Checked = nodeChecked;
      if ( node->Nodes->Count > 0 )
      {
         
         // If the current node has child nodes, call the CheckAllChildsNodes method recursively.
         this->CheckAllChildNodes( node, nodeChecked );
      }
   }
}

// NOTE   This code can be added to the BeforeCheck event handler instead of the AfterCheck event.
// After a tree node's Checked property is changed, all its child nodes are updated to the same value.
void node_AfterCheck( Object^ /*sender*/, TreeViewEventArgs^ e )
{
   // The code only executes if the user caused the checked state to change.
   if ( e->Action != TreeViewAction::Unknown )
   {
      if ( e->Node->Nodes->Count > 0 )
      {
         /* Calls the CheckAllChildNodes method, passing in the current
             Checked value of the TreeNode whose checked state changed. */
         this->CheckAllChildNodes( e->Node, e->Node->Checked );
      }
   }
}
// Updates all child tree nodes recursively.
private void CheckAllChildNodes(TreeNode treeNode, bool nodeChecked)
{
   foreach(TreeNode node in treeNode.Nodes)
   {
      node.Checked = nodeChecked;
      if(node.Nodes.Count > 0)
      {
         // If the current node has child nodes, call the CheckAllChildsNodes method recursively.
         this.CheckAllChildNodes(node, nodeChecked);
      }
   }
}

// NOTE   This code can be added to the BeforeCheck event handler instead of the AfterCheck event.
// After a tree node's Checked property is changed, all its child nodes are updated to the same value.
private void node_AfterCheck(object sender, TreeViewEventArgs e)
{
   // The code only executes if the user caused the checked state to change.
   if(e.Action != TreeViewAction.Unknown)
   {
      if(e.Node.Nodes.Count > 0)
      {
         /* Calls the CheckAllChildNodes method, passing in the current 
         Checked value of the TreeNode whose checked state changed. */
         this.CheckAllChildNodes(e.Node, e.Node.Checked);
      }
   }
}
' Updates all child tree nodes recursively.
Private Sub CheckAllChildNodes(treeNode As TreeNode, nodeChecked As Boolean)
   Dim node As TreeNode
   For Each node In  treeNode.Nodes 
      node.Checked = nodeChecked
      If node.Nodes.Count > 0 Then
         ' If the current node has child nodes, call the CheckAllChildsNodes method recursively.
         Me.CheckAllChildNodes(node, nodeChecked)
      End If
   Next node
End Sub
      
' NOTE   This code can be added to the BeforeCheck event handler instead of the AfterCheck event.
' After a tree node's Checked property is changed, all its child nodes are updated to the same value.
Private Sub node_AfterCheck(sender As Object, e As TreeViewEventArgs) Handles treeView1.AfterCheck
   ' The code only executes if the user caused the checked state to change.
   If e.Action <> TreeViewAction.Unknown Then 
      If e.Node.Nodes.Count > 0 Then
         ' Calls the CheckAllChildNodes method, passing in the current 
         ' Checked value of the TreeNode whose checked state changed. 
         Me.CheckAllChildNodes(e.Node, e.Node.Checked)
      End If
   End If
End Sub 

注釈

BeforeCheck TreeNode.CheckedまたはAfterCheckイベントハンドラー内からプロパティを設定すると、イベントが複数回発生し、予期しない動作が発生する可能性があります。Setting the TreeNode.Checked property from within a BeforeCheck or AfterCheck event handler causes the event to be raised multiple times and can result in unexpected behavior. イベントが何度も発生しないようにするには、 Action TreeViewEventArgsのプロパティがにTreeViewAction.Unknown設定されていない場合にのみ、再帰コードを実行するロジックをイベントハンドラーに追加します。To prevent the event from being raised multiple times, add logic to your event handler that only executes your recursive code if the Action property of the TreeViewEventArgs is not set to TreeViewAction.Unknown.

イベントの処理の詳細については、「処理とイベントの発生」を参照してください。For more information about handling events, see Handling and Raising Events.

適用対象

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