清单文件添加

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:sharedUserId="android.uid.system"
    >

1.获取当前语言：

Locale.getDefault().getLanguage()；

2.切换语言：

//// 此处需要声明权限:android.permission.CHANGE_CONFIGURATION
//// android:configChanges="keyboardHidden|orientation|screenSize"
//// 会重新调用 onCreate();

        try {
            Class classActivityManagerNative = Class.forName("android.app.ActivityManagerNative");
            Method getDefault = classActivityManagerNative.getDeclaredMethod("getDefault");
            Object objIActivityManager = getDefault.invoke(classActivityManagerNative);
            Class classIActivityManager = Class.forName("android.app.IActivityManager");
            Method getConfiguration = classIActivityManager.getDeclaredMethod("getConfiguration");

            Configuration config = (Configuration) getConfiguration.invoke(objIActivityManager);
            //new Locale(ZH,"CN");中文
            //new Locale(EN,"US");英文
            config.setLocale(locale);
            
            Class clzConfig = Class.forName("android.content.res.Configuration");
            java.lang.reflect.Field userSetLocale = clzConfig.getField("userSetLocale");
            userSetLocale.set(config, true);
            Class[] clzParams = {Configuration.class};
            Method updateConfiguration = classIActivityManager.getDeclaredMethod("updateConfiguration", clzParams);
            updateConfiguration.invoke(objIActivityManager, config);

        } catch (Exception e) {
          e.printStackTrace();
        }

时间相关

添加权限

  <uses-permission android:name="android.permission.WRITE_SETTINGS"/>
  <uses-permission android:name="android.permission.WRITE_SECURE_SETTINGS"/>

1.判断是否是12小时制

DateFormat.is24HourFormat(mContext);

2.判断日期时间是否自动获取

    public boolean isDateTimeAuto() {
        try {
            return android.provider.Settings.Global.getInt(mContext.getContentResolver(),
                    android.provider.Settings.Global.AUTO_TIME) > 0;
        } catch (Settings.SettingNotFoundException e) {
            e.printStackTrace();
            return false;
        }
    }

3.设置时区自动获取，设置时区

        android.provider.Settings.Global.putInt(mContext.getContentResolver(),
                android.provider.Settings.Global.AUTO_TIME_ZONE, 1);//自动获取时区
        setTimeZone(getDefaultTimeZone());

4.设置12/24小时制

  android.provider.Settings.System.putString(mContext.getContentResolver(),
                android.provider.Settings.System.TIME_12_24, "12");

  android.provider.Settings.System.putString(mContext.getContentResolver(),
                android.provider.Settings.System.TIME_12_24, "24");

5.设置系统日期

public void setSysDate(int year,int month,int day){
  Calendar c = Calendar.getInstance();
  c.set(Calendar.YEAR, year);
  c.set(Calendar.MONTH, month);
  c.set(Calendar.DAY_OF_MONTH, day);

  long when = c.getTimeInMillis();

  if(when / 1000 < Integer.MAX_VALUE){
      ((AlarmManager)mContext.getSystemService(Context.ALARM_SERVICE)).setTime(when);
  }
}

6.设置系统时间

public void setSysTime(int hour,int minute){
  Calendar c = Calendar.getInstance();
  c.set(Calendar.HOUR_OF_DAY, hour);
  c.set(Calendar.MINUTE, minute);
  c.set(Calendar.SECOND, 0);
  c.set(Calendar.MILLISECOND, 0);

  long when = c.getTimeInMillis();

  if(when / 1000 < Integer.MAX_VALUE){
      ((AlarmManager)mContext.getSystemService(Context.ALARM_SERVICE)).setTime(when);
  }
}

6.设置系统时区

public void setTimeZone(String timeZone){
  final Calendar now = Calendar.getInstance();
  TimeZone tz = TimeZone.getTimeZone(timeZone);
  now.setTimeZone(tz);
}

6.获取当前系统时区

public String getDefaultTimeZone(){
  return TimeZone.getDefault().getDisplayName();
}

注意清单中权限，后续还需要系统签名文件和打包，安装和卸载命令。