Replace line break characters with <br /> in ASP.NET MVC Razor view

I have a textarea control that accepts input. I am trying to later render that text to a view by simply using:

> @Model.CommentText

This is properly encoding any values. However, I want to replace the line break characters with <br /> and I can't find a way to make sure that the new br tags don't get encoded. I have tried using HtmlString but haven't had any luck yet.

Use the CSS white-space property instead of opening yourself up to XSS vulnerabilities!

<span style="white-space: pre-line">@Model.CommentText</span>

Try the following:

@MvcHtmlString.Create(Model.CommentText.Replace(Environment.NewLine, "<br />"))

Update:

According to marcind's comment on this related question, the ASP.NET MVC team is looking to implement something similar to the <%: and <%= for the Razor view engine.

Update 2:

We can turn any question about HTML encoding into a discussion on harmful user inputs, but enough of that already exists.

Anyway, take care of potential harmful user input.

@MvcHtmlString.Create(Html.Encode(Model.CommentText).Replace(Environment.NewLine, "<br />"))

Update 3 (Asp.Net MVC 3):

@Html.Raw(Html.Encode(Model.CommentText).Replace("\n", "<br />"))

Split on newlines (environment agnostic) and print regularly -- no need to worry about encoding or xss:

@if (!string.IsNullOrWhiteSpace(text)) 
{
	var lines = text.Split(new[] { '\r', '\n' }, StringSplitOptions.RemoveEmptyEntries);
	foreach (var line in lines)
	{
		<p>@line</p>
	}
}

(remove empty entries is optional)

Omar's third solution as an HTML Helper would be:

public static IHtmlString FormatNewLines(this HtmlHelper helper, string input)
{
    return helper.Raw(helper.Encode(input).Replace("\n", "<br />"));
}

Applying the DRY principle to Omar's solution, here's an HTML Helper extension:

using System.Web.Mvc;
using System.Text.RegularExpressions;

namespace System.Web.Mvc.Html {
    public static class MyHtmlHelpers {
        public static MvcHtmlString EncodedReplace(this HtmlHelper helper, string input, string pattern, string replacement) {
            return new MvcHtmlString(Regex.Replace(helper.Encode(input), pattern, replacement));
        }
    }
}

Usage (with improved regex):

@Html.EncodedReplace(Model.CommentText, "[\n\r]+", "<br />")

This also has the added benefit of putting less onus on the Razor View developer to ensure security from XSS vulnerabilities.

---

My concern with Jacob's solution is that rendering the line breaks with CSS breaks the HTML semantics.

I needed to break some text into paragraphs ("p" tags), so I created a simple helper using some of the recommendations in previous answers (thank you guys).

public static MvcHtmlString ToParagraphs(this HtmlHelper html, string value) 
    { 
        value = html.Encode(value).Replace("\r", String.Empty);
        var arr = value.Split('\n').Where(a => a.Trim() != string.Empty);
        var htmlStr = "<p>" + String.Join("</p><p>", arr) + "</p>";
        return MvcHtmlString.Create(htmlStr);
    }

Usage:

@Html.ToParagraphs(Model.Comments)

I prefer this method as it doesn't require manually emitting markup. I use this because I'm rendering Razor Pages to strings and sending them out via email, which is an environment where the white-space styling won't always work.

public static IHtmlContent RenderNewlines<TModel>(this IHtmlHelper<TModel> html, string content)
{
	if (string.IsNullOrEmpty(content) || html is null)
	{
		return null;
	}

	TagBuilder brTag = new TagBuilder("br");
	IHtmlContent br = brTag.RenderSelfClosingTag();
	HtmlContentBuilder htmlContent = new HtmlContentBuilder();

	// JAS: On the off chance a browser is using LF instead of CRLF we strip out CR before splitting on LF.
	string lfContent = content.Replace("\r", string.Empty, StringComparison.InvariantCulture);
	string[] lines = lfContent.Split('\n', StringSplitOptions.None);
	foreach(string line in lines)
	{
		_ = htmlContent.Append(line);
		_ = htmlContent.AppendHtml(br);
	}

	return htmlContent;
}