string.xml 中的 Android 引用字符串

Question

Is it possible to reference a string in strings.xml

Eg:

<string name="application_name">@string/first_name Browser</string>
<string name="first_name">Chrome</string>

Where depending on requirements, i can switch the value of first_name to "Chrome", "Firefox" or "Opera".

Answer 1

You can give the reference of string resource, but limitation are as follows

<string name="first_name">Chrome</string>
<string name="application_name">@string/first_name</string> // gives "Chrome"
<string name="application_name">Chrome @string/first_name</string> // gives "Chrome @string/first_name"
<string name="application_name">@string/first_name Chrome </string> // gives error

If content starts with "@" then Android considers this is a referenced string, see last case which gives an error because Android's tools take @ and the next string to it as the string's reference name, it will try to find a resource called "@string/first_name Chrome" which doesn't exist.

You can use String Format to dynamically assign sub-strings like <string name="application_name">%1$s browser</string>

to use

String text = String.format(res.getString(R.string.application_name), "Chrome");

Answer 2

Yes, you can do so without having to add any Java/Kotlin code, using this small library that allows you to do so using XML only at buildtime. So for your case, you'd have to set up your strings like this:

<string name="application_name">${first_name} Browser</string>
<string name="first_name">Chrome</string>

And then after running the gradle plugin, you'll get this:

<!-- Auto generated during compilation -->
<string name="application_name">Chrome Browser</string>

This is the link to the library: https://github.com/LikeTheSalad/android-stem

Disclaimer: I'm the author of this library.

Answer 3

The Strings in the strings.xml are fixed and cannot be changed at run time. You will have to define a string for each case, and do the switch in the code.

String name;

if (/* browser is Chrome*/) {
    name = getString(R.string.first_name_chrome);
} else if (/* browser is Firefox */) {
    name = getString(R.string.first_name_firefox);
}

You can however make the application select the correct string for different languages automatically. This can be done by placing string files in localized folders (values-en, values-fr, values-pl etc).

You can read more about localization at http://www.icanlocalize.com/site/tutorials/android-application-localization-tutorial/