WPF C# How to set formatted text in TextBlock using Text property

Question

I need to set the text of a TextBlock code behind to a string containing formatted text.

For example this string:

"This is a <Bold>message</Bold> with bold formatted text"

If I put this text in xaml file in this way it work correctly

<TextBlock>
  This is a <Bold>message</Bold> with bold formatted text
</TextBlock>

But if I set it using the Text property don't work.

string myString = "This is a <Bold>message</Bold> with bold formatted text";
myTextBlock.Text = myString;

I know I can use Inlines:

myTextBlock.Inlines.Add("This is a");
myTextBlock.Inlines.Add(new Run("message") { FontWeight = FontWeights.Bold });
myTextBlock.Inlines.Add("with bold formatted text");

But the problem is that I get the string as it is from another source and I have no idea how I can pass this string to the TextBlock and see if formatted. I hope there is a way to set the content of the TextBlock directly with the formatted string, because I have no idea of how I can parse the string to use it with Inlines.

It looks like your trying to copy formatted text from another application (Microsoft Word?) and paste it into your TextBlock, is that a correct assumption? — hcham1
I get this string from another application but I don't get it by copy/past but from TCP connection — user2272143
How is the string formatted when you receive it? Will it look just like "This is a <Bold>message</Bold> with bold formatted text" — hcham1
I can also get the string in different formats. ie. <Bold></Bold> or <b></b>. I donìt know how thi can be useful but it give me this option. — user2272143

Clemens Clemens · Accepted Answer · 2018-11-27T23:19:05

You may parse a TextBlock from your string and return a collection of its Inlines:

private IEnumerable<Inline> ParseInlines(string text)
{
    var textBlock = (TextBlock)XamlReader.Parse(
        "<TextBlock xmlns=\"http://schemas.microsoft.com/winfx/2006/xaml/presentation\">"
        + text
        + "</TextBlock>");

    return textBlock.Inlines.ToList(); // must be enumerated
}

Then add the collection to your TextBlock:

textBlock.Inlines.AddRange(
    ParseInlines("This is a <Bold>message</Bold> with bold formatted text"));

WPF C# How to set formatted text in TextBlock using Text property

2 Answers