Question

I have a WPF .NET 4 C# RichTextBox and I’m wanting to replace certain characters within that text box with other characters, this is to happen on the KeyUp event.

What I’m trying to achieve is replace acronyms with full words, e.g.:

pc = personal computer

sc = starcraft

etc…

I’ve looked a few similar threads, but anything I’ve found hasn’t been successful in my scenario.

Ultimately, I’d like to be able to do this with a list of acronyms. However, I’m having issues with even replacing a single acronym, can anyone help?

Answer 1

Because System.Windows.Controls.RichTextBox does not have a property for Text to detect its value, you may detect its value using the following

string _Text = new TextRange(richTextBox1.Document.ContentStart, richTextBox1.Document.ContentEnd).Text;

Then, you may change _Text and post the new string using the following

_Text = _Text.Replace("pc", "Personal Computer");
if (_Text != new TextRange(richTextBox1.Document.ContentStart, richTextBox1.Document.ContentEnd).Text)
{
new TextRange(richTextBox1.Document.ContentStart, richTextBox1.Document.ContentEnd).Text = _Text;
}

So, it’d look like this

string _Text = new TextRange(richTextBox1.Document.ContentStart, richTextBox1.Document.ContentEnd).Text;
_Text = _Text.Replace("pc", "Personal Computer"); // Replace pc with Personal Computer
if (_Text != new TextRange(richTextBox1.Document.ContentStart, richTextBox1.Document.ContentEnd).Text)
{
new TextRange(richTextBox1.Document.ContentStart, richTextBox1.Document.ContentEnd).Text = _Text; // Change the current text to _Text
}

Remark: Instead of using Text.Replace("pc", "Personal Computer"); you may declare a List<String> in which you save the characters and its replacements

Example:

    List<string> _List = new List<string>();
    private void richTextBox1_TextChanged(object sender, TextChangedEventArgs e)
    {

        string _Text = new TextRange(richTextBox1.Document.ContentStart, richTextBox1.Document.ContentEnd).Text;
        for (int count = 0; count < _List.Count; count++)
        {
            string[] _Split = _List[count].Split(','); //Separate each string in _List[count] based on its index
            _Text = _Text.Replace(_Split[0], _Split[1]); //Replace the first index with the second index
        }
        if (_Text != new TextRange(richTextBox1.Document.ContentStart, richTextBox1.Document.ContentEnd).Text)
        {
        new TextRange(richTextBox1.Document.ContentStart, richTextBox1.Document.ContentEnd).Text = _Text;
        }
    }

    private void Window_Loaded(object sender, RoutedEventArgs e)
    {
        // The comma will be used to separate multiple items
        _List.Add("pc,Personal Computer");
        _List.Add("sc,Star Craft");

    }

Thanks,

I hope you find this helpful 🙂