Can I underline text in an Android layout?

The "accepted" answer above does NOT work (when you try to use the string like textView.setText(Html.fromHtml(String.format(getString(...), ...))).

As stated in the documentations you must escape (html entity encoded) opening bracket of the inner tags with <, e.g. result should look like:

<resource>
    <string name="your_string_here">This is an &lt;u&gt;underline&lt;/u&gt;.</string>
</resources>

Then in your code you can set the text with:

TextView textView = (TextView) view.findViewById(R.id.textview);
textView.setText(Html.fromHtml(String.format(getString(R.string.my_string), ...)));

You can try with

textview.setPaintFlags(textview.getPaintFlags() |   Paint.UNDERLINE_TEXT_FLAG);

It can be achieved if you are using a string resource xml file, which supports HTML tags like <b></b>, <i></i> and <u></u>.

<resources>
    <string name="your_string_here"><![CDATA[This is an <u>underline</u>.]]></string>
</resources>

If you want to underline something from code use:

TextView textView = (TextView) view.findViewById(R.id.textview);
SpannableString content = new SpannableString("Content");
content.setSpan(new UnderlineSpan(), 0, content.length(), 0);
textView.setText(content);

Strings.xml file content:

<resource>
     <string name="my_text">This is an <u>underline</u>.</string> 
</resources> 

Layout xml file shold use the above string resource with below properties of textview, as shown below:

<TextView 
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:gravity="center_horizontal"
    android:text="@string/my_text"

    android:selectAllOnFocus="false"
    android:linksClickable="false"
    android:autoLink="all"
    />