TreeView.AfterCollapse Evento
Importante
Parte de la información hace referencia a la versión preliminar del producto, que puede haberse modificado sustancialmente antes de lanzar la versión definitiva. Microsoft no otorga ninguna garantía, explícita o implícita, con respecto a la información proporcionada aquí.
Se produce después de contraerse el nodo de árbol.
public:
event System::Windows::Forms::TreeViewEventHandler ^ AfterCollapse;C#
public event System.Windows.Forms.TreeViewEventHandler AfterCollapse;member this.AfterCollapse : System.Windows.Forms.TreeViewEventHandler Public Custom Event AfterCollapse As TreeViewEventHandler En el ejemplo de código siguiente se actualizan todos los nodos de árbol secundario de cuando TreeNode el usuario cambia su estado comprobado. Este código requiere que tenga un Form objeto con un TreeView que tenga TreeNode objetos en su TreeNodeCollection. TreeNodeCollection debe tener nodos de árbol con nodos secundarios.
// 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 );
}
}
}
C#
// 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
Para obtener más información acerca de cómo controlar eventos, vea controlar y provocar eventos.
| Producto | Versiones |
|---|---|
| .NET Framework | 1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8 |
| Windows Desktop | 3.0, 3.1, 5, 6, 7 |