TreeViewEventArgs.Action TreeViewEventArgs.Action TreeViewEventArgs.Action TreeViewEventArgs.Action Property

Definición

Obtiene el tipo de acción que ha generado el evento.Gets the type of action that raised the event.

public:
 property System::Windows::Forms::TreeViewAction Action { System::Windows::Forms::TreeViewAction get(); };
public System.Windows.Forms.TreeViewAction Action { get; }
member this.Action : System.Windows.Forms.TreeViewAction
Public ReadOnly Property Action As TreeViewAction

Valor de propiedad

Tipo de TreeViewAction que ha provocado el evento.The type of TreeViewAction that raised the event.

Ejemplos

En el ejemplo siguiente se muestra un TreeViewpersonalizado.The following example illustrates a customized TreeView. Al heredar la TreeView clase, esta versión personalizada tiene toda la funcionalidad de una normal TreeView.By inheriting the TreeView class, this custom version has all the functionality of a normal TreeView. Cambiar varios valores de propiedad en el constructor proporciona una apariencia única.Changing various property values in the constructor provides a unique appearance. Dado que ShowPlusMinus la propiedad está establecida en false, el control personalizado también invalida el OnAfterSelect método para que los nodos puedan expandirse y contraerse cuando se haga clic en ellos.Because the ShowPlusMinus property is set to false, the customized control also overrides the OnAfterSelect method so nodes can be expanded and collapsed when they are clicked.

Un control personalizado de esta manera se puede usar en toda la organización, lo que facilita proporcionar una interfaz coherente sin requerir que se especifiquen las propiedades del control en cada proyecto individual.A control that is customized in this way can be used throughout an organization, making it easy to provide a consistent interface without requiring the control properties to be specified in each individual project.

public ref class CustomizedTreeView: public TreeView
{
public:
   CustomizedTreeView()
   {

      // Customize the TreeView control by setting various properties.
      BackColor = System::Drawing::Color::CadetBlue;
      FullRowSelect = true;
      HotTracking = true;
      Indent = 34;
      ShowPlusMinus = false;

      // The ShowLines property must be false for the FullRowSelect
      // property to work.
      ShowLines = false;
   }

protected:
   virtual void OnAfterSelect( TreeViewEventArgs^ e ) override
   {
      // Confirm that the user initiated the selection.
      // This prevents the first node from expanding when it is
      // automatically selected during the initialization of
      // the TreeView control.
      if ( e->Action != TreeViewAction::Unknown )
      {
         if ( e->Node->IsExpanded )
         {
            e->Node->Collapse();
         }
         else
         {
            e->Node->Expand();
         }
      }

      
      // Remove the selection. This allows the same node to be
      // clicked twice in succession to toggle the expansion state.
      SelectedNode = nullptr;
   }
};
public class CustomizedTreeView : TreeView
{
    public CustomizedTreeView()
    {
        // Customize the TreeView control by setting various properties.
        BackColor = System.Drawing.Color.CadetBlue;
        FullRowSelect = true;
        HotTracking = true;
        Indent = 34;
        ShowPlusMinus = false;

        // The ShowLines property must be false for the FullRowSelect 
        // property to work.
        ShowLines = false;
    }

    protected override void OnAfterSelect(TreeViewEventArgs e)
    {
        // Confirm that the user initiated the selection.
        // This prevents the first node from expanding when it is
        // automatically selected during the initialization of 
        // the TreeView control.
        if (e.Action != TreeViewAction.Unknown)
        {
            if (e.Node.IsExpanded) 
            {
                e.Node.Collapse();
            }
            else 
            {
                e.Node.Expand();
            }
        }

        // Remove the selection. This allows the same node to be
        // clicked twice in succession to toggle the expansion state.
        SelectedNode = null;
    }

}
Public Class CustomizedTreeView
    Inherits TreeView

    Public Sub New()
        ' Customize the TreeView control by setting various properties.
        BackColor = System.Drawing.Color.CadetBlue
        FullRowSelect = True
        HotTracking = True
        Indent = 34
        ShowPlusMinus = False

        ' The ShowLines property must be false for the FullRowSelect 
        ' property to work.
        ShowLines = False
    End Sub 'New


    Protected Overrides Sub OnAfterSelect(ByVal e As TreeViewEventArgs)
        ' Confirm that the user initiated the selection.
        ' This prevents the first node from expanding when it is
        ' automatically selected during the initialization of 
        ' the TreeView control.
        If e.Action <> TreeViewAction.Unknown Then
            If e.Node.IsExpanded Then
                e.Node.Collapse()
            Else
                e.Node.Expand()
            End If
        End If

        ' Remove the selection. This allows the same node to be
        ' clicked twice in succession to toggle the expansion state.
        SelectedNode = Nothing
    End Sub 'OnAfterSelect

End Class 'CustomizedTreeView 

Se aplica a

Consulte también: