String resourcesA string resource provides text strings for your application with optional text styling and formatting. There are three types of resources that can provide your application with strings: Show All strings are capable of applying some styling markup and formatting arguments. For information about styling and formatting strings, see the section about Formatting and Styling. StringA single string that can be referenced from the application or from other resource files (such as an XML layout). Note: A string is a simple resource that is referenced using the value provided in the name attribute (not the name of the XML file). So, you can combine string resources with other simple resources in the one XML file, under one <resources> element. file location: res/values/filename.xmlThe filename is arbitrary. The <string> element's name is used as the resource ID. compiled resource datatype: Resource pointer to a String. resource reference: In Java: R.string.string_name In XML:@string/string_name syntax: <?xml version="1.0" encoding="utf-8"?> <resources> <string name="string_name" >text_string</string> </resources> elements: <resources> Required. This must be the root node. No attributes. <string> A string, which can include styling tags. Beware that you must escape apostrophes and quotation marks. For more information about how to properly style and format your strings see Formatting and Styling, below.attributes: name String. A name for the string. This name is used as the resource ID. example: XML file saved at res/values/strings.xml: <?xml version="1.0" encoding="utf-8"?> <resources> <string name="hello">Hello!</string> </resources>This layout XML applies a string to a View: <TextView android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="@string/hello" />This application code retrieves a string: Kotlinval string: String = getString(R.string.hello)JavaString string = getString(R.string.hello);You can use either getString(int) or getText(int) to retrieve a string. getText(int) retains any rich text styling applied to the string. String arrayAn array of strings that can be referenced from the application. Note: A string array is a simple resource that is referenced using the value provided in the name attribute (not the name of the XML file). As such, you can combine string array resources with other simple resources in the one XML file, under one <resources> element. file location: res/values/filename.xmlThe filename is arbitrary. The <string-array> element's name is used as the resource ID. compiled resource datatype: Resource pointer to an array of Strings. resource reference: In Java: R.array.string_array_name In XML: @[package:]array/string_array_name syntax: <?xml version="1.0" encoding="utf-8"?> <resources> <string-array name="string_array_name"> <item >text_string</item> </string-array> </resources> elements: <resources> Required. This must be the root node. No attributes. <string-array> Defines an array of strings. Contains one or more <item> elements.attributes: name String. A name for the array. This name is used as the resource ID to reference the array. <item> A string, which can include styling tags. The value can be a reference to another string resource. Must be a child of a <string-array> element. Beware that you must escape apostrophes and quotation marks. See Formatting and Styling, below, for information about to properly style and format your strings.No attributes. example: XML file saved at res/values/strings.xml: <?xml version="1.0" encoding="utf-8"?> <resources> <string-array name="planets_array"> <item>Mercury</item> <item>Venus</item> <item>Earth</item> <item>Mars</item> </string-array> </resources>This application code retrieves a string array: Kotlinval array: Array = resources.getStringArray(R.array.planets_array)JavaResources res = getResources(); String[] planets = res.getStringArray(R.array.planets_array);Quantity strings (plurals)Different languages have different rules for grammatical agreement with quantity. In English, for example, the quantity 1 is a special case. We write "1 book", but for any other quantity we'd write "n books". This distinction between singular and plural is very common, but other languages make finer distinctions. The full set supported by Android is zero, one, two, few, many, and other. The rules for deciding which case to use for a given language and quantity can be very complex, so Android provides you with methods such as getQuantityString() to select the appropriate resource for you. Although historically called "quantity strings" (and still called that in API), quantity strings should only be used for plurals. It would be a mistake to use quantity strings to implement something like Gmail's "Inbox" versus "Inbox (12)" when there are unread messages, for example. It might seem convenient to use quantity strings instead of an if statement, but it's important to note that some languages (such as Chinese) don't make these grammatical distinctions at all, so you'll always get the other string. The selection of which string to use is made solely based on grammatical necessity. In English, a string for zero is ignored even if the quantity is 0, because 0 isn't grammatically different from 2, or any other number except 1 ("zero books", "one book", "two books", and so on). Conversely, in Korean only the other string is ever used. Don't be misled either by the fact that, say, two sounds like it could only apply to the quantity 2: a language may require that 2, 12, 102 (and so on) are all treated like one another but differently to other quantities. Rely on your translator to know what distinctions their language actually insists upon. It's often possible to avoid quantity strings by using quantity-neutral formulations such as "Books: 1". This makes your life and your translators' lives easier, if it's an acceptable style for your application. Note: A plurals collection is a simple resource that is referenced using the value provided in the name attribute (not the name of the XML file). As such, you can combine plurals resources with other simple resources in the one XML file, under one <resources> element. file location: res/values/filename.xmlThe filename is arbitrary. The <plurals> element's name is used as the resource ID. resource reference: In Java: R.plurals.plural_name syntax: <?xml version="1.0" encoding="utf-8"?> <resources> <plurals name="plural_name"> <item quantity=["zero" | "one" | "two" | "few" | "many" | "other"] >text_string</item> </plurals> </resources> elements: <resources> Required. This must be the root node. No attributes. <plurals> A collection of strings, of which, one string is provided depending on the amount of something. Contains one or more <item> elements.attributes: name String. A name for the pair of strings. This name is used as the resource ID. <item> A plural or singular string. The value can be a reference to another string resource. Must be a child of a <plurals> element. Beware that you must escape apostrophes and quotation marks. See Formatting and Styling, below, for information about to properly style and format your strings.attributes: quantity Keyword. A value indicating when this string should be used. Valid values, with non-exhaustive examples in parentheses: ValueDescription zeroWhen the language requires special treatment of the number 0 (as in Arabic). oneWhen the language requires special treatment of numbers like one (as with the number 1 in English and most other languages; in Russian, any number ending in 1 but not ending in 11 is in this class). twoWhen the language requires special treatment of numbers like two (as with 2 in Welsh, or 102 in Slovenian). fewWhen the language requires special treatment of "small" numbers (as with 2, 3, and 4 in Czech; or numbers ending 2, 3, or 4 but not 12, 13, or 14 in Polish). manyWhen the language requires special treatment of "large" numbers (as with numbers ending 11-99 in Maltese). otherWhen the language does not require special treatment of the given quantity (as with all numbers in Chinese, or 42 in English). example: XML file saved at res/values/strings.xml: <?xml version="1.0" encoding="utf-8"?> <resources> <plurals name="numberOfSongsAvailable"> <!-- As a developer, you should always supply "one" and "other" strings. Your translators will know which strings are actually needed for their language. Always include %d in "one" because translators will need to use %d for languages where "one" doesn't mean 1 (as explained above). --> <item quantity="one">%d song found.</item> <item quantity="other">%d songs found.</item> </plurals> </resources>XML file saved at res/values-pl/strings.xml: <?xml version="1.0" encoding="utf-8"?> <resources> <plurals name="numberOfSongsAvailable"> <item quantity="one">Znaleziono %d piosenkę.</item> <item quantity="few">Znaleziono %d piosenki.</item> <item quantity="other">Znaleziono %d piosenek.</item> </plurals> </resources>Usage: Kotlinval count = getNumberOfSongsAvailable() val songsFound = resources.getQuantityString(R.plurals.numberOfSongsAvailable, count, count)Javaint count = getNumberOfSongsAvailable(); Resources res = getResources(); String songsFound = res.getQuantityString(R.plurals.numberOfSongsAvailable, count, count);When using the getQuantityString() method, you need to pass the count twice if your string includes string formatting with a number. For example, for the string %d songs found, the first count parameter selects the appropriate plural string and the second count parameter is inserted into the %d placeholder. If your plural strings do not include string formatting, you don't need to pass the third parameter to getQuantityString. Format and styleHere are a few important things you should know about how to properly format and style your string resources. Handle special charactersWhen a string contains characters that have special usage in XML, you must escape the characters according to the standard XML/HTML escaping rules. If you need to escape a character that has special meaning in Android you should use a preceding backslash. By default Android will collapse sequences of whitespace characters into a single space. You can avoid this by enclosing the relevant part of your string in double quotes. In this case all whitespace characters (including new lines) will get preserved within the quoted region. Double quotes will allow you to use regular single unescaped quotes as well. Character Escaped form(s) @ \@ ? \? New line \n Tab \t U+XXXX Unicode character \uXXXX Single quote (')Any of the following:
Note that surrounding the string with single quotes does not work. Whitespace collapsing and Android escaping happens after your resource file gets parsed as XML. This means that <string>      </string> (space, punctuation space, Unicode Em space) all collapse to a single space (""), because they are all Unicode spaces after the file is parsed as an XML. To preserve those spaces as they are, you can either quote them (<string>"      "</string>) or use Android escaping (<string> \u0032 \u8200 \u8195</string>). Note: From XML parser's perspective, there is no difference between <string>"Test this"</string> and <string>"Test this"</string> whatsoever. Both forms will not show any quotes but trigger Android whitespace-preserving quoting (that will have no practical effect in this case). Formatting stringsIf you need to format your strings, then you can do so by putting your format arguments in the string resource, as demonstrated by the following example resource. <string name="welcome_messages">Hello, %1$s! You have %2$d new messages.</string>In this example, the format string has two arguments: %1$s is a string and %2$d is a decimal number. Then, format the string by calling getString(int, Object...). For example: Kotlinvar text = getString(R.string.welcome_messages, username, mailCount)JavaString text = getString(R.string.welcome_messages, username, mailCount);Styling with HTML markupYou can add styling to your strings with HTML markup. For example: <?xml version="1.0" encoding="utf-8"?> <resources> <string name="welcome">Welcome to <b>Android</b>!</string> </resources>The following HTML elements are supported:
If you aren't applying formatting, you can set TextView text directly by calling setText(java.lang.CharSequence). In some cases, however, you may want to create a styled text resource that is also used as a format string. Normally, this doesn't work because the format(String, Object...) and getString(int, Object...) methods strip all the style information from the string. The work-around to this is to write the HTML tags with escaped entities, which are then recovered with fromHtml(String), after the formatting takes place. For example:
Because the fromHtml(String) method formats all HTML entities, be sure to escape any possible HTML characters in the strings you use with the formatted text, using htmlEncode(String). For instance, if you are formatting a string that contains characters such as "<" or "&", then they must be escaped before formatting, so that when the formatted string is passed through fromHtml(String), the characters come out the way they were originally written. For example: Kotlinval escapedUsername: String = TextUtils.htmlEncode(username) val text: String = getString(R.string.welcome_messages, escapedUsername, mailCount) val styledText: Spanned = Html.fromHtml(text, FROM_HTML_MODE_LEGACY)JavaString escapedUsername = TextUtils.htmlEncode(username); String text = getString(R.string.welcome_messages, escapedUsername, mailCount); Spanned styledText = Html.fromHtml(text);Styling with spannablesA Spannable is a text object that you can style with typeface properties such as color and font weight. You use SpannableStringBuilder to build your text and then apply styles defined in the android.text.style package to the text. You can use the following helper methods to set up much of the work of creating spannable text: Kotlin/** * Returns a CharSequence that concatenates the specified array of CharSequence * objects and then applies a list of zero or more tags to the entire range. * * @param content an array of character sequences to apply a style to * @param tags the styled span objects to apply to the content * such as android.text.style.StyleSpan */ private fun apply(content: Array<out CharSequence>, vararg tags: Any): CharSequence { return SpannableStringBuilder().apply { openTags(tags) content.forEach { charSequence -> append(charSequence) } closeTags(tags) } } /** * Iterates over an array of tags and applies them to the beginning of the specified * Spannable object so that future text appended to the text will have the styling * applied to it. Do not call this method directly. */ private fun Spannable.openTags(tags: Array<out Any>) { tags.forEach { tag -> setSpan(tag, 0, 0, Spannable.SPAN_MARK_MARK) } } /** * "Closes" the specified tags on a Spannable by updating the spans to be * endpoint-exclusive so that future text appended to the end will not take * on the same styling. Do not call this method directly. */ private fun Spannable.closeTags(tags: Array<out Any>) { tags.forEach { tag -> if (length > 0) { setSpan(tag, 0, length, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE) } else { removeSpan(tag) } } }Java/** * Returns a CharSequence that concatenates the specified array of CharSequence * objects and then applies a list of zero or more tags to the entire range. * * @param content an array of character sequences to apply a style to * @param tags the styled span objects to apply to the content * such as android.text.style.StyleSpan * */ private static CharSequence applyStyles(CharSequence[] content, Object[] tags) { SpannableStringBuilder text = new SpannableStringBuilder(); openTags(text, tags); for (CharSequence item : content) { text.append(item); } closeTags(text, tags); return text; } /** * Iterates over an array of tags and applies them to the beginning of the specified * Spannable object so that future text appended to the text will have the styling * applied to it. Do not call this method directly. */ private static void openTags(Spannable text, Object[] tags) { for (Object tag : tags) { text.setSpan(tag, 0, 0, Spannable.SPAN_MARK_MARK); } } /** * "Closes" the specified tags on a Spannable by updating the spans to be * endpoint-exclusive so that future text appended to the end will not take * on the same styling. Do not call this method directly. */ private static void closeTags(Spannable text, Object[] tags) { int len = text.length(); for (Object tag : tags) { if (len > 0) { text.setSpan(tag, 0, len, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE); } else { text.removeSpan(tag); } } }The following bold, italic, and color methods wrap the helper methods above and demonstrate specific examples of applying styles defined in the android.text.style package. You can create similar methods to do other types of text styling. Kotlin/** * Returns a CharSequence that applies boldface to the concatenation * of the specified CharSequence objects. */ fun bold(vararg content: CharSequence): CharSequence = apply(content, StyleSpan(Typeface.BOLD)) /** * Returns a CharSequence that applies italics to the concatenation * of the specified CharSequence objects. */ fun italic(vararg content: CharSequence): CharSequence = apply(content, StyleSpan(Typeface.ITALIC)) /** * Returns a CharSequence that applies a foreground color to the * concatenation of the specified CharSequence objects. */ fun color(color: Int, vararg content: CharSequence): CharSequence = apply(content, ForegroundColorSpan(color))Java/** * Returns a CharSequence that applies boldface to the concatenation * of the specified CharSequence objects. */ public static CharSequence bold(CharSequence... content) { return apply(content, new StyleSpan(Typeface.BOLD)); } /** * Returns a CharSequence that applies italics to the concatenation * of the specified CharSequence objects. */ public static CharSequence italic(CharSequence... content) { return apply(content, new StyleSpan(Typeface.ITALIC)); } /** * Returns a CharSequence that applies a foreground color to the * concatenation of the specified CharSequence objects. */ public static CharSequence color(int color, CharSequence... content) { return apply(content, new ForegroundColorSpan(color)); }Here's an example of how to chain these methods together to apply various styles to individual words within a phrase: Kotlin// Create an italic "hello, " a red "world", // and bold the entire sequence. val text: CharSequence = bold(italic(getString(R.string.hello)), color(Color.RED, getString(R.string.world)))Java// Create an italic "hello, " a red "world", // and bold the entire sequence. var text = bold(italic(getString(R.string.hello)), color(Color.RED, getString(R.string.world))) </pre> </section><section><h3 id="java">Java</h3> <pre class="prettyprint lang-java"> // Create an italic "hello, " a red "world", // and bold the entire sequence. CharSequence text = bold(italic(getString(R.string.hello)), color(Color.RED, getString(R.string.world)));The core-ktx Kotlin module also contains extension functions that make working with spans even easier. You can check out the android.text package documentation on GitHub to learn more. For more information on working with spans, see the following links:
Styling with annotationsYou can apply complex or custom styling by using the Annotation class along with the <annotation> tag in your strings.xml resource files. The annotation tag allows you to mark parts of the string for custom styling by defining custom key-value pairs in the XML that the framework then converts into Annotation spans. You can then retrieve these annotations and use the key and value to apply the styling. When creating annotations, make sure you add the <annotation> tag to all translations of the string in every strings.xml file.
Applying a custom typeface to the word text in all languages Example - adding a custom typeface
If youre using the same text multiple times, you should construct the SpannableString object once and reuse it as needed to avoid potential performance and memory issues. For more examples of annotation usage, see Styling internationalized text in Android Annotation spans and text parcelingBecause Annotation spans are also ParcelableSpans, the key-value pairs are parceled and unparceled. As long as the receiver of the parcel knows how to interpret the annotations, you can use Annotation spans to apply custom styling to the parceled text. To keep your custom styling when you pass the text to an Intent Bundle, you first need to add Annotation spans to your text. You can do this in the XML resources via the <annotation> tag, as shown in the example above, or in code by creating a new Annotation and setting it as a span, as shown below: Kotlinval spannableString = SpannableString("My spantastic text") val annotation = Annotation("font", "title_emphasis") spannableString.setSpan(annotation, 3, 7, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE) // start Activity with text with spans val intent = Intent(this, MainActivity::class.java) intent.putExtra(TEXT_EXTRA, spannableString) startActivity(intent)JavaSpannableString spannableString = new SpannableString("My spantastic text"); Annotation annotation = new Annotation("font", "title_emphasis"); spannableString.setSpan(annotation, 3, 7, 33); // start Activity with text with spans Intent intent = new Intent(this, MainActivity.class); intent.putExtra(TEXT_EXTRA, spannableString); this.startActivity(intent);Retrieve the text from the Bundle as a SpannableString and then parse the annotations attached, as shown in the example above. Kotlin// read text with Spans val intentCharSequence = intent.getCharSequenceExtra(TEXT_EXTRA) as SpannableStringJava// read text with Spans SpannableString intentCharSequence = (SpannableString)intent.getCharSequenceExtra(TEXT_EXTRA);For more information on text styling, see the following links:
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