Returns a value that indicates whether the most recent action can be undone.

Namespace:  C1.Win.XmlEditor
Assembly:  C1.Win.XmlEditor.2 (in C1.Win.XmlEditor.2.dll)

Syntax

C#
public bool CanUndo()
Visual Basic (Declaration)
Public Function CanUndo As Boolean

Return Value

True if the most recent action can be undone; otherwise, False.

Examples

This example shows how to create a custom context menu that can be linked to a C1XmlEditor control and has Undo and Redo buttons.
Copy CodeC#
class MyContextMenuStrip : ContextMenuStrip
{
    private C1XmlEditor _owner;
    private ToolStripMenuItem _btnUndo, _btnRedo;

    public MyContextMenuStrip(C1XmlEditor editor)
    {
        // save reference to parent control
        _owner = editor;

        // create menu items
        _btnUndo = (ToolStripMenuItem)Items.Add("Undo");
        _btnUndo.ShortcutKeys = Keys.Control | Keys.Z;
        _btnRedo = (ToolStripMenuItem)Items.Add("Redo");
        _btnRedo.ShortcutKeys = Keys.Control | Keys.Y;
    }

    protectedoverridevoid OnItemClicked(ToolStripItemClickedEventArgs e)
    {
        Close();

        if (e.ClickedItem == _btnUndo)
            _owner.Undo();
        elseif (e.ClickedItem == _btnRedo)
            _owner.Redo();
        base.OnItemClicked(e);
    }

    protectedoverridevoid OnOpening(System.ComponentModel.CancelEventArgs e)
    {
        _btnUndo.Enabled = _owner.CanUndo;
        _btnRedo.Enabled = _owner.CanCut;
        base.OnOpening(e);
    }

See Also