CODEWITHSUNDEEP
c#wpfrichtextbox
devios1
devios1

Reputation: 38035

Detecting hyperlinks in WPF RichTextBox

Hey folks, I'm wanting to write some rudimentary support for detecting hyperlinks in a WPF RichTextBox control. My plan is to use a regex to identify any links and then manually replace them with real hyperlink objects.

However the part I am having trouble with is getting the correct textpointers, etc. once I find a link. For example, I can flatten the entire document to a text string and find links, but once I do that how can I get the proper pointer to the block that needs url-ifying?

Perhaps a better approach would be to iterate over blocks in the document, assuming a url would not span multiple blocks, however even then I have very little experience working with the RichTextBox/FlowDocument object model so any pointers (pun intended) would be helpful. Thanks!

Upvotes: 0

Views: 2022

Answers (2)

Christopher Rath
Christopher Rath

Reputation: 31

I've been struggling with this problem, off and on, for several months. Today, I decided to ask Bing Chat how to do this. I gave Bing the following direction: write c# code to extend the .net RichTextBox control in a WPF application so that urls are clickable.

Bing provided the following solution...

To extend the .NET RichTextBox control in a WPF application using C# to make URLs clickable, you can use the TextPointer class to find the start and end positions of the URLs in the text. Here’s an example of how to create an extension method for the RichTextBox control:

public static class RichTextBoxExtensions
{
    public static void MakeUrlsClickable(this RichTextBox self)
    {
        TextPointer pointer = self.Document.ContentStart;
        while (pointer != null)
        {
            if (pointer.GetPointerContext(LogicalDirection.Forward) == TextPointerContext.Text)
            {
                string textRun = pointer.GetTextInRun(LogicalDirection.Forward);
                MatchCollection matches = Regex.Matches(textRun, @"(https?://[^\s]+)");
                foreach (Match match in matches)
                {
                    TextPointer start = pointer.GetPositionAtOffset(match.Index);
                    TextPointer end = start.GetPositionAtOffset(match.Length);
                    Hyperlink hyperlink = new Hyperlink(start, end);
                    hyperlink.NavigateUri = new Uri(match.Value);
                }
            }
            pointer = pointer.GetNextContextPosition(LogicalDirection.Forward);
        }
    }
}

    /// To use this method: 
    ///     (1) Add the following Setter to the RichTextBox control:
    ///         <RichTextBox.Resources>
    ///             <Style TargetType = "Hyperlink" >
    ///                 <Setter Property="Cursor" Value="Hand" />
    ///                 <EventSetter Event = "MouseLeftButtonDown" Handler="Hyperlink_MouseLeftButtonDown" />
    ///             </Style>
    ///         <RichTextBox.Resources>
    ///     (2) Add the following codebehind:
    ///         private void Hyperlink_MouseLeftButtonDown(object sender, MouseEventArgs e)
    ///         {
    ///             var hyperlink = (Hyperlink)sender;
    ///             Process.Start(new ProcessStartInfo(hyperlink.NavigateUri.ToString())
    ///             {
    ///                 UseShellExecute = true,
    ///             });
    ///         e.Handled = true;
    ///         }
    ///         
    /// The genisis of the codebehind and Setter code was found here:
    ///     https://stackoverflow.com/questions/762271/clicking-hyperlinks-in-a-richtextbox-without-holding-down-ctrl-wpf

Upvotes: 0

Darren
Darren

Reputation: 4488

I think you might find this useful:

http://blogs.msdn.com/b/prajakta/archive/2006/10/17/autp-detecting-hyperlinks-in-richtextbox-part-i.aspx

Upvotes: 0

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