how to make Textbox text as Hyperlink in WPF

wpf-4.0, wpf-controls, xaml

Solution

First, I'm not sure why you'd want to do this... if the text becomes a clickable hyperlink the instant it's a valid URI, how would you continue to edit it?

The Hyperlink control doesn't do anything special for you and it can't be hosted in a TextBox. Instead, use a regular TextBox, check the text for a valid URI every time it's updated, and apply a style to make the text look like a clickable link.

<TextBox TextChanged="TextBox_TextChanged" MouseDoubleClick="TextBox_MouseDoubleClick">
    <TextBox.Style>
        <Style TargetType="TextBox">
            <Style.Triggers>
                <DataTrigger Binding="{Binding HasValidURI}" Value="True">
                    <Setter Property="TextDecorations" Value="Underline"/>
                    <Setter Property="Foreground" Value="#FF2A6DCD"/>
                </DataTrigger>
            </Style.Triggers>
        </Style>
    </TextBox.Style>
</TextBox>

Every time the text is changed, `TextBox_TextChanged` is called. This checks whether the text is a valid URI using `Uri.TryCreate()`. If so, a property `HasValidURI` is set to `true`. A `DataTrigger` in the `TextBox's` style picks this up and makes the text underlined and blue.

Making the hyperlink immediately clickable would cause you not to be able to position the cursor, so I watch for a double-click instead. When one is received, convert the text to a URI again and kick off a `Process` with that URI.

public partial class MainWindow : Window, INotifyPropertyChanged
{
    private bool _hasValidURI;

    public bool HasValidURI
    {
        get { return _hasValidURI; }
        set { _hasValidURI = value; OnPropertyChanged( "HasValidURI" ); }
    }

    public event PropertyChangedEventHandler PropertyChanged;

    public void OnPropertyChanged( string name )
    {
        var handler = PropertyChanged;
        if( handler != null ) handler( this, new PropertyChangedEventArgs( name ) );
    }

    public MainWindow()
    {
        InitializeComponent();
        this.DataContext = this;
    }

    private void TextBox_TextChanged( object sender, TextChangedEventArgs e )
    {
        Uri uri;
        HasValidURI = Uri.TryCreate( (sender as TextBox).Text, UriKind.Absolute, out uri );
    }

    private void TextBox_MouseDoubleClick( object sender, MouseButtonEventArgs e )
    {
        Uri uri;
        if( Uri.TryCreate( (sender as TextBox).Text, UriKind.Absolute, out uri ) )
        {
            Process.Start( new ProcessStartInfo( uri.AbsoluteUri ) );
        }
    }
}

Problem

Original source