Android 获取系统语言环境的不同方法

Question

所以，我发现有两种方法可以在 Android 中获取系统的语言环境：

Locale.getDefault()

和

getResources().getConfiguration().locale

基本上问题是 - 这两个的输出可以不同吗？或者它们总是相同的，我可以使用第一个，因为它不需要 Context 对象？

Answer 1

区域当前 = getResources().getConfiguration().locale;

如果您的应用程序需要更改设置，您可能会发现此值更新得更快。

你的另一个方法中没有

Answer 2

引自this page:

Be wary of the default locale

Note that there are many convenience methods that automatically use the default locale, but using them may lead to subtle bugs.

The default locale is appropriate for tasks that involve presenting data to the user. In this case, you want to use the user's date/time formats, number formats, rules for conversion to lowercase, and so on. In this case, it's safe to use the convenience methods.

The default locale is not appropriate for machine-readable output. The best choice there is usually Locale.US – this locale is guaranteed to be available on all devices, and the fact that it has no surprising special cases and is frequently used (especially for computer-computer communication) means that it tends to be the most efficient choice too.

A common mistake is to implicitly use the default locale when producing output meant to be machine-readable. This tends to work on the developer's test devices (especially because so many developers use en_US), but fails when run on a device whose user is in a more complex locale.

For example, if you're formatting integers some locales will use non-ASCII decimal digits. As another example, if you're formatting floating-point numbers some locales will use ',' as the decimal point and '.' for digit grouping. That's correct for human-readable output, but likely to cause problems if presented to another computer (parseDouble(String) can't parse such a number, for example). You should also be wary of the toLowerCase() and toUpperCase() overloads that don't take a Locale: in Turkey, for example, the characters 'i' and 'I' won't be converted to 'I' and 'i'. This is the correct behavior for Turkish text (such as user input), but inappropriate for, say, HTTP headers.

Answer 3

AFAIK，您可以使用其中任何一种，除非您的应用程序本身使用一种方式篡改语言环境（Locale.setDefault() 而不是 config.locale，反之亦然）

原因如下：

ResourcesManager.applyConfigurationToResourcesLocked() #275:

public final boolean applyConfigurationToResourcesLocked(Configuration config,
        CompatibilityInfo compat)
    ...

    // set it for java, this also affects newly created Resources
    if (config.locale != null) {
        Locale.setDefault(config.locale);
    }

    Resources.updateSystemConfiguration(config, defaultDisplayMetrics, compat);
    ApplicationPackageManager.configurationChanged();
    ...

Android 获取系统语言环境的不同方法

Android get system locale different approaches

android

locale

android-resources

android-configchanges