How to use formatted strings together with placeholders in Android?

In Android it is possible to use placeholders in strings, such as:

<string name="number">My number is %1$d</string>

and then in Java code (inside a subclass of Activity):

String res = getString(R.string.number);
String formatted = String.format(res, 5);

or even simpler:

String formatted = getString(R.string.number, 5);

It is also possible to use some HTML tags in Android string resources:

<string name="underline"><u>Underline</u> example</string>

Since the String itself cannot hold any information about formatting, one should use getText(int) instead of getString(int) method:

CharSequence formatted = getText(R.string.underline);

The returned CharSequence can be then passed to Android widgets, such as TextView, and the marked phrase will be underlined.

However, I could not find how to combine these two methodes, using formatted string together with placeholders:

<string name="underlined_number">My number is <u>%1$d</u></string>

How to process above resource in the Java code to display it in a TextView, substituting %1$d with an integer?

Finally I managed to find a working solution and wrote my own method for replacing placeholders, preserving formatting:

public static CharSequence getText(Context context, int id, Object... args) {
    for(int i = 0; i < args.length; ++i)
        args[i] = args[i] instanceof String? TextUtils.htmlEncode((String)args[i]) : args[i];
    return Html.fromHtml(String.format(Html.toHtml(new SpannedString(context.getText(id))), args));
}

This approach does not require to escape HTML tags manually neither in a string being formatted nor in strings that replace placeholders.

Kotlin extension function that

works with all API versions
handles multiple arguments

Example usage

textView.text = context.getText(R.string.html_formatted, "Hello in bold")

HTML string resource wrapped in a CDATA section

<string name="html_formatted"><![CDATA[ bold text: <B>%1$s</B>]]></string>

Result

bold text: Hello in bold

Code

/**
* Create a formatted CharSequence from a string resource containing arguments and HTML formatting
*
* The string resource must be wrapped in a CDATA section so that the HTML formatting is conserved.
*
* Example of an HTML formatted string resource:
* <string name="html_formatted"><![CDATA[ bold text: <B>%1$s</B> ]]></string>
*/
fun Context.getText(@StringRes id: Int, vararg args: Any?): CharSequence =
    HtmlCompat.fromHtml(String.format(getString(id), *args), HtmlCompat.FROM_HTML_MODE_COMPACT)

<resources>
  <string name="welcome_messages">Hello, %1$s! You have &lt;b>%2$d new messages&lt;/b>.</string>
</resources>


Resources res = getResources();
String text = String.format(res.getString(R.string.welcome_messages), username, mailCount);
CharSequence styledText = Html.fromHtml(text);

More Infos here: http://developer.android.com/guide/topics/resources/string-resource.html