CODEWITHSUNDEEP
wpfxamlmvvm
Tarun Arora
Tarun Arora

Reputation: 4822

WPF Replace smiley's in a message with smiley icons

I am writing a chat application in WPF (using MVVM), When the user submits a message into the chat stream, I want to replace any smiley expressions such as :-) :-/ :-D, etc by actual smiley icons.

I have written a converter to do a linear search on the message and identify a smiley. My question is once I have identified a smiley expression, how can I replace the block of text which contains the smiley with the actual icon?

If you feel there is a better or efficient way of doing this, I would love to know...

public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
    {
        // The message passed in to the converter by calling XAML code
        var message = System.Convert.ToString(value);

        // Perform a linear search on the message 
        for (int i = 0; i < message.Length - 1; i++)
        {
            var c = message[i];

            // Look for the character ':'
            if (c == ':'
                // Ensure that it has 2 more characters after it
                && i + 2 <= message.Length - 1 &&
                // If it's the last character then that's fine
                ((i + 2 == message.Length - 1) ||
                // Or else it should be followed by an empty space
                (i + 3 <= message.Length - 1 && message[i + 3] == ' ')))
            {
                var expression = message.Substring(i, 3);

                message = message**.Replace(expression, @".\Emotions\1.png");**
            }
        }

        return message;
    }

The converter is called from my XAML

<TextBlock Text="{Binding Content, Converter={converter:EmotionConverter}}" />

This doesn't work, I think it just replaces the text, i instead need a way to pass back an image, any advise how I could do this?

Upvotes: 0

Views: 423

Answers (1)

AgentFire
AgentFire

Reputation: 9780

First, you need to switch the property from Text, which is simply a string, to InlineCollection which is exactly what you are looking for.

Then, in your converter, you should return that collection based on the string you receive, and

  • When you need to return a text line, you return Run class with text inside.
  • When you need to return an image, you return an Image class either itself or wrapped into the UIContainer or so, I can't recall right now the right name of that class. :)

Upvotes: 1

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