Grokking Android

Getting Down to the Nitty Gritty of Android Development

Android Quick Tip: Formatting Text with Html.fromHtml()

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Android offers you the possibility to easily format text with HTML markup. Thus it's easy to create text like this:

Sample screen showing some formattings
Sample screen showing some formattings

You probably are going to use bold or italics the most, but there are many more supported.

Here is the list of all supported tags. You can find it in the source of android.text.Html's inner class HtmlToSpannedConverter:

Supported HTML-Tags
Tags Format
b, strong Bold
i, em, cite, dfn Italics
u Underline
sub Subtext
sup Supertext
big Big
small Small
tt Monospace
h1 ... h6 Headlines
img Image
font Font face and color
blockquote For longer quotes
a Link
div, p Paragraph
br Linefeed

Formatting text from your strings.xml

If you want to support text formatting from within your strings.xml file, you have to escape the tags - or use a CDATA section (thanks to Jose Miguel for pointing this out). Otherwise Android simply ignores them when reading the resource file.

To escape the tags you just need to replace all "<" characters. Luckily you do not have to escape the ">" characters as well. That way the HTML structure is still at least kind of readable. But only kind of.

If you use many HTML tags a CDATA section is better. For the sample above it looks like this:



      <![CDATA[
      
Text with markup for bold
      and italic text.

There is also support for a teletype-style font. But no use for the code tag!

]]>

Even if you can add a lot of HTML tags, you are better off using only minor styling as mixing too much styles makes your text look uneasy instead of being more striking.

The following snippet shows how to use this string from within your Java code:


TextView view = (TextView)findViewById(R.id.sampleText);
String formattedText = getString(R.string.htmlFormattedText);
Spanned result = Html.fromHtml(formattedText);
view.setText(result);

Alternatives to consider

For longer texts that use HTML tags, I recommend to use raw files instead.

For more complicated formatting a WebView probably would be better.

Wolfram Rittmeyer lives in Germany and has been developing with Java for many years.

He has been interested in Android for quite a while and has been blogging about all kind of topics around Android.

You can find him on Google+ and Twitter.