undo/redo command stack for InkCanvas - wpf

Question

I am creating paint like application using InkCanvas , I am willing to implement Undo
and Redo functionality in my application .
Which is the best way to implement Undo / Redo for InkCanvas ??

Answer 1

I've implemented undo / redo for a WPF application and ended up publishing my undo / redo code to http://muf.codeplex.com/. You can also get it via NuGet. Just look for "MUF" or "Monitored Undo Framework". It includes support for Silverlight 4.0, as well as .NET 3.5, 4.0, and WP7.
In my WPF app, we also had an InkCanvas that supported Undo / Redo. In my case, the strokes for the InkCanvas were saved to a database with the rest of the data. I hooked the various events on InkCanvas to detect when the strokes had changed. Then used these events to update the entities.
The entities tracked the changes to the strokes and integrated into the Undo / Redo library. When the user clicked Undo, the library would alter the entities back to their original state. Then I'd push those strokes back into the InkCanvas and trigger a layout update.
Comments and questions are welcome on the codeplex site ( http://muf.codeplex.com/ ). You'll also find complete documentation and sample apps there.

Answer 2

I know its too late but if someone is here for InkCanvas only than this answer might help:
public partial class MainWindow : Window
{
System.Windows.Ink.StrokeCollection _added;
System.Windows.Ink.StrokeCollection _removed;
private bool handle = true;
public MainWindow()
{
InitializeComponent();
inkCanvas1.Strokes.StrokesChanged += Strokes_StrokesChanged;
}
private void Strokes_StrokesChanged(object sender, System.Windows.Ink.StrokeCollectionChangedEventArgs e)
{
if(handle)
{
_added = e.Added;
_removed = e.Removed;
}
}
private void Undo(object sender, RoutedEventArgs e)
{
handle = false;
inkCanvas1.Strokes.Remove(_added);
inkCanvas1.Strokes.Add(_removed);
handle = true;
}
private void Redo(object sender, RoutedEventArgs e)
{
handle = false;
inkCanvas1.Strokes.Add(_added);
inkCanvas1.Strokes.Remove(_removed);
handle = true;
}
}
And in XAML:
<InkCanvas x:Name="inkCanvas1" Width="100" Height="100" Background="Yellow"/>
<Button Content="Undo" Click="Undo" />
<Button Content="Redo" Click="Redo"/>

Answer 3

I don't know if this helps.. But one very easy way to UNDO is:
YourWindow.xaml.cs
private void Undo_Click(object sender, RoutedEventArgs e)
{
if (YourInkCanva.Strokes.Count > 0)
{
YourInkCanva.Strokes.RemoveAt(YourInkCanva.Strokes.Count - 1);
}
else
{
// Else Do Nothing.
}
}
You would want to replace YourInkCanva with the name of your inkcanva.