CODEWITHSUNDEEP
c#.netwpfrichtextbox
Slippy
Slippy

Reputation: 1343

Richtextbox - on undo?

I need to be able to detect if an "undo" has been triggered, and whether or not it has had an effect on the contents of my RichTextBox.

Of I type content into the RichTextBox at the minute, and press Ctrl+Z, windows seems to handle the undo for me. I want to be able to write code that will get triggered straight after that. I have been looking around and can't find anything.

Thanks in advance.

Upvotes: 2

Views: 1412

Answers (5)

marsh-wiggle
marsh-wiggle

Reputation: 2813

As already described, CommandBindings can be used. I prefer binding to each control instead of binding to all controls of a specific class. This can be done in the following way:

this.richTextBox.CommandBindings.Add(
    new CommandBinding(ApplicationCommands.Undo, this.RichTextBoxUndoEvent));


private void RichTextBoxUndoEvent(object sender, ExecutedRoutedEventArgs e)
{
    e.Handled = true;
    this.richTextBox.Undo();
}

Upvotes: 0

LionAM
LionAM

Reputation: 1401

Starting from .Net 3.0, there is a simple built-in way to get notified when an undo command (among others) is executed:

CommandManager.RegisterClassCommandBinding(typeof(MyClass),
    new CommandBinding(ApplicationCommands.Undo, OnUndo));

Just call this line of code in the static constructor (or somewhere else) and add a static method:

private static void OnUndo(object sender, ExecutedRoutedEventArgs e)
{
    //your code
}

Upvotes: 2

Floc
Floc

Reputation: 698

If I well understand you, you want to compare content before and after the Ctr+Z.

Then you should do :

In XAML File :

<RichTextBox PreviewKeyDown="RichTextBox_PreviewKeyDown" KeyUp="RichTextBox_KeyUp" />

In CS File :

private void RichTextBox_KeyUp(object sender, KeyEventArgs e)
{
    if (Keyboard.Modifiers == ModifierKeys.Control && e.Key == Key.Z)
    {
        Console.WriteLine("After : " + new TextRange(((RichTextBox)sender).Document.ContentStart, ((RichTextBox)sender).Document.ContentEnd).Text);
    }
}

private void RichTextBox_PreviewKeyDown(object sender, KeyEventArgs e)
{
    if (Keyboard.Modifiers == ModifierKeys.Control && e.Key == Key.Z)
    {
        Console.WriteLine("Before : " + new TextRange(((RichTextBox)sender).Document.ContentStart, ((RichTextBox)sender).Document.ContentEnd).Text);
    }
}

Then, you will see in the output of your application the content of your RichTextBox before the Ctrl+Z and the content after.

I've try it and it works fine !

Upvotes: 0

Omar
Omar

Reputation: 16623

WINFORM:

You could exploit the KeyDown event and detect if Ctrl+Z is pressed:

richTextBox.KeyDown += new KeyEventHandler(richTextBox_KeyDown);

private void richTextBox_KeyDown(object sender, KeyEventArgs e){
    if (e.Modifiers == Keys.Control && e.KeyCode == Keys.Z){
        //undo detected, do something
    }
}

WPF :

richTextBox.KeyUp += new KeyEventHandler(richTextBox_KeyUp);

void richTextBox_KeyUp(object sender, KeyEventArgs e) {
    if (Keyboard.Modifiers == ModifierKeys.Control && e.Key == Key.Z) {
        //undo detected, do something
    }
}

Upvotes: 1

MasterMastic
MasterMastic

Reputation: 21306

I think you're going to have to implement that yourself. I'm not aware of an event out of the box that will suit your needs.

You might also want to have a look at Monitored Undo Framework.
And here for additional reading.

Upvotes: 0

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