How to convert HTML text into plain text using C#?


I have a requirement in which I need to render/display plain text from HTML content, so I would like to know how can I do it using C#?

For example, below is my HTML code

<p>Some text here</p>
<div>Some more <strong>text</strong></div>

I would like to have output as below in plain text

Some text here. Some more text

Any sample code or tutorial to do it?


Asked by:- jon
2
: 11257 At:- 6/6/2018 11:49:35 AM
C# HTML to plain text







2 Answers
profileImage Answered by:- vikas_jk

You can create a helper class to convert your HTML content into plain text and use the below method written in C#

 public static string HTMLToText(string HTMLCode)
        {
            // Remove new lines since they are not visible in HTML
            HTMLCode = HTMLCode.Replace("\n", " ");

            // Remove tab spaces
            HTMLCode = HTMLCode.Replace("\t", " ");

            // Remove multiple white spaces from HTML
            HTMLCode = Regex.Replace(HTMLCode, "\\s+", " ");

            // Remove HEAD tag
            HTMLCode = Regex.Replace(HTMLCode, "<head.*?</head>", ""
                                , RegexOptions.IgnoreCase | RegexOptions.Singleline);

            // Remove any JavaScript
            HTMLCode = Regex.Replace(HTMLCode, "<script.*?</script>", ""
              , RegexOptions.IgnoreCase | RegexOptions.Singleline);

            // Replace special characters like &, <, >, " etc.
            StringBuilder sbHTML = new StringBuilder(HTMLCode);
            // Note: There are many more special characters, these are just
            // most common. You can add new characters in this arrays if needed
            string[] OldWords = {"&nbsp;", "&amp;", "&quot;", "&lt;",
   "&gt;", "&reg;", "&copy;", "&bull;", "&trade;","&#39;"};
            string[] NewWords = { " ", "&", "\"", "<", ">", "®", "©", "•", "™","\'" };
            for (int i = 0; i < OldWords.Length; i++)
            {
                sbHTML.Replace(OldWords[i], NewWords[i]);
            }

            // Check if there are line breaks (<br>) or paragraph (<p>)
            sbHTML.Replace("<br>", "\n<br>");
            sbHTML.Replace("<br ", "\n<br ");
            sbHTML.Replace("<p ", "\n<p ");

            // Finally, remove all HTML tags and return plain text
            return System.Text.RegularExpressions.Regex.Replace(
              sbHTML.ToString(), "<[^>]*>", "");
        }

The above method takes the HTML content and remove's all the HTML tags and code and provide you output as plain text, you can check the online sample here http://rextester.com/AKMG13869

Go to the above link and run it, you can see output as

Some text here Some more text

done.

OR

you can also use HTML HtmlAgilityPack to convert HTML to text in C#

Example:

var sampleText = HtmlUtilities.ConvertToPlainText(string html);

Thanks.

2
At:- 6/7/2018 3:16:58 PM Updated at:- 7/26/2022 2:50:22 PM
perfect answer, that's what i was looking for, thank you 0
By : jon - at :- 6/18/2018 2:27:32 PM


profileImage Answered by:- bhanu

You can also use HTMLAgility Pack for .NET and then directly convert HTML into plain text in C#, here is the sample code

using System;
using HtmlAgilityPack;
using System.IO;
					
public class Program
{
	public static void Main()
	{
		var html = @"<html><head><meta name=""Generator"" content=""Microsoft Exchange Server"">
<!-- converted from text -->
<style><!-- .EmailQuote { margin-left: 1pt; padding-left: 4pt; border-left: #800000 2px solid; } --></style></head>
<body>
<font size=""2""><span style=""font-size:11pt;""><div class=""PlainText""> <p>Hello world, how are you doing today?</p><p>This is a separate <b>paragraph</b></p></div></span></font>
</body>
</html>";
		var plainText = ConvertHtml(html);
		Console.WriteLine(plainText);
	}
	public static string Convert(string path)
    {
        HtmlDocument doc = new HtmlDocument();
        doc.Load(path);

        StringWriter sw = new StringWriter();
        ConvertTo(doc.DocumentNode, sw);
        sw.Flush();
        return sw.ToString();
    }

    public static string ConvertHtml(string html)
    {
        HtmlDocument doc = new HtmlDocument();
        doc.LoadHtml(html);

        StringWriter sw = new StringWriter();
        ConvertTo(doc.DocumentNode, sw);
        sw.Flush();
        return sw.ToString();
    }

    public static void ConvertContentTo(HtmlNode node, TextWriter outText)
    {
        foreach(HtmlNode subnode in node.ChildNodes)
        {
            ConvertTo(subnode, outText);
        }
    }

    public static void ConvertTo(HtmlNode node, TextWriter outText)
    {
        string html;
        switch(node.NodeType)
        {
            case HtmlNodeType.Comment:
                // don't output comments
                break;

            case HtmlNodeType.Document:
                ConvertContentTo(node, outText);
                break;

            case HtmlNodeType.Text:
                // script and style must not be output
                string parentName = node.ParentNode.Name;
                if ((parentName == "script") || (parentName == "style"))
                    break;

                // get text
                html = ((HtmlTextNode)node).Text;

                // is it in fact a special closing node output as text?
                if (HtmlNode.IsOverlappedClosingElement(html))
                    break;

                // check the text is meaningful and not a bunch of whitespaces
                if (html.Trim().Length > 0)
                {
                    outText.Write(HtmlEntity.DeEntitize(html));
                }
                break;

            case HtmlNodeType.Element:
                switch(node.Name)
                {
                    case "p":
                        // treat paragraphs as crlf
                        outText.Write("\r\n");
                        break;
                }

                if (node.HasChildNodes)
                {
                    ConvertContentTo(node, outText);
                }
                break;
        }
	}
}

Working Fiddle link: https://dotnetfiddle.net/pXgXly

Hope it helps.

1
At:- 5/20/2021 1:00:17 PM






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