I need to convert HTML documents into valid XML, preferably XHTML. What's the best way to do this? Does anybody know a toolkit/library/sample/...whatever that helps me to get that task done?
To be a bit more clear here, my application has to do the conversion automatically at runtime. I don't look for a tool that helps me to move some pages to XHTML manually.
Convert from HTML to XML with HTML Tidy
JRoppert, For your need, i guess you might want to look at the Sources
c:\temp>tidy -help
tidy [option...] [file...] [option...] [file...]
Utility to clean up and pretty print HTML/XHTML/XML
see http://tidy.sourceforge.net/
Options for HTML Tidy for Windows released on 14 February 2006:
File manipulation
-----------------
-output <file>, -o write output to the specified <file>
<file>
-config <file> set configuration options from the specified <file>
-file <file>, -f write errors to the specified <file>
<file>
-modify, -m modify the original input files
Processing directives
---------------------
-indent, -i indent element content
-wrap <column>, -w wrap text at the specified <column>. 0 is assumed if
<column> <column> is missing. When this option is omitted, the
default of the configuration option "wrap" applies.
-upper, -u force tags to upper case
-clean, -c replace FONT, NOBR and CENTER tags by CSS
-bare, -b strip out smart quotes and em dashes, etc.
-numeric, -n output numeric rather than named entities
-errors, -e only show errors
-quiet, -q suppress nonessential output
-omit omit optional end tags
-xml specify the input is well formed XML
-asxml, -asxhtml convert HTML to well formed XHTML
-ashtml force XHTML to well formed HTML
-access <level> do additional accessibility checks (<level> = 0, 1, 2, 3).
0 is assumed if <level> is missing.
Character encodings
-------------------
-raw output values above 127 without conversion to entities
-ascii use ISO-8859-1 for input, US-ASCII for output
-latin0 use ISO-8859-15 for input, US-ASCII for output
-latin1 use ISO-8859-1 for both input and output
-iso2022 use ISO-2022 for both input and output
-utf8 use UTF-8 for both input and output
-mac use MacRoman for input, US-ASCII for output
-win1252 use Windows-1252 for input, US-ASCII for output
-ibm858 use IBM-858 (CP850+Euro) for input, US-ASCII for output
-utf16le use UTF-16LE for both input and output
-utf16be use UTF-16BE for both input and output
-utf16 use UTF-16 for both input and output
-big5 use Big5 for both input and output
-shiftjis use Shift_JIS for both input and output
-language <lang> set the two-letter language code <lang> (for future use)
Miscellaneous
-------------
-version, -v show the version of Tidy
-help, -h, -? list the command line options
-xml-help list the command line options in XML format
-help-config list all configuration options
-xml-config list all configuration options in XML format
-show-config list the current configuration settings
Use --blah blarg for any configuration option "blah" with argument "blarg"
Input/Output default to stdin/stdout respectively
Single letter options apart from -f may be combined
as in: tidy -f errs.txt -imu foo.html
For further info on HTML see http://www.w3.org/MarkUp
You can use a HTML Agility Pack. Its open-source project from CodePlex.
The Validator.nu HTML Parser comes with an HTML2XML sample program that does the conversion using the HTML5 parsing algorithm and infoset coercion rules.
Use Html2Xhtml for .NET 4.0:
In-memory string-to-string conversion:
var xhtml = Html2Xhtml.RunAsFilter(stdin => stdin.Write(html)).ReadToEnd();
In-memory string-to-XDocument conversion:
var xdoc = Html2Xhtml.RunAsFilter(stdin => stdin.Write(html)).ReadToXDocument();
See http://corsis.sourceforge.net/index.php/Html2Xhtml for more information.
http://corsis.sourceforge.net/index.php/Html2Xhtmlhttp://corsis.sourceforge.net/index.php/Html2Xhtml
Html2Xhtml is a .NET 4.0 library for converting HTML to XHTML licensed under GPLv2 or above.
I tested Html2Xhtml in the local reconstruction of a large online database of the European Union. Tidy/Tidy.NET would not even produce valid output most of the time, Chilkat's HTML-to-XML was a bit slow and produced strange results (misplaced, missing, unexplainable elements). In attempt to find a free, fast and reliable conversion tool I created this library. It converts 2 - 4x faster than all other libraries I tested.
Html2Xhtml, combined with the power of LINQ to XML, is an excellent tool for all large-scale data extraction and web crawling scenarios.
you can convert html to xhtml with tidy executable file:
tidy -asxhtml -numeric < index.html > index.xhml
you can check the c# implementation here.
The easiest way is to set your Visual Studio IDE to identify the changes you need to make. You can do this in Visual Studio 2008 by going to: Tools, Options, Text Editor, HTML, Validation and choosing the appropriate target. Possibly XHTML 1.1 or XHTML 1.0 Transitional.
For some information on the different types, read: http://msdn.microsoft.com/en-us/library/aa479043.aspx
Then you need to work through the points highlighted on your page.
来源：https://stackoverflow.com/questions/138555/how-to-convert-html-to-xhtml