如何在Android上创建本地化的时间前的String

时间：2012-11-02 21:04:14

标签： android localization

我正在审核Google I/O Session 2012 app并遇到了这个TODO 

public static String getTimeAgo(long time, Context ctx) {
    if (time < 1000000000000L) {
        // if timestamp given in seconds, convert to millis
        time *= 1000;
    }

    long now = getCurrentTime(ctx);
    if (time > now || time <= 0) {
        return null;
    }

    // TODO: localize
    final long diff = now - time;
    if (diff < MINUTE_MILLIS) {
        return "just now";
    } else if (diff < 2 * MINUTE_MILLIS) {
        return "a minute ago";
    } else if (diff < 50 * MINUTE_MILLIS) {
        return diff / MINUTE_MILLIS + " minutes ago";
    } else if (diff < 90 * MINUTE_MILLIS) {
        return "an hour ago";
    } else if (diff < 24 * HOUR_MILLIS) {
        return diff / HOUR_MILLIS + " hours ago";
    } else if (diff < 48 * HOUR_MILLIS) {
        return "yesterday";
    } else {
        return diff / DAY_MILLIS + " days ago";
    }
}

这让我想知道本地化的步骤是什么。

4 个答案:

答案 0 :(得分：19)

如果您不需要自定义字符串，您还可以使用DateUtils.getRelativeTimeSpanString，它会产生以下字符串：

  • 42分钟前
  • 10秒前
  • 在1小时内

样本用法：

final CharSequence relativeTimeSpan = DateUtils.getRelativeTimeSpanString(time, now, 0);

答案 1 :(得分：9)

来自Ian Lake的回答：

final CharSequence relativeTimeSpan = DateUtils.getRelativeTimeSpanString(time, now, 0);

DateUtils.getRelativeTimeSpanString产生如下内容：

  • 42分钟前
  • 10秒前
  • 在1小时内

或者，这将允许使用给定的res通过Android Context框架提供翻译，如果您从框架方法中获得所需的消息传递差异，则非常有用。

public static String getTimeAgo(long time, Context context) {
    if (time < 1000000000000L)
        // if timestamp given in seconds, convert to millis
        time *= 1000;

    final long now = getCurrentTime(context);
    if (time > now || time <= 0) return "";


    final Resources res = context.getResources();
    final long time_difference = now - time;
    if (time_difference < _A_MINUTE)
        return res.getString(R.string.just_now);
    else if (time_difference < 50 * _A_MINUTE)
        return res.getString(R.string.time_ago,
                             res.getQuantityString(R.plurals.minutes, (int) time_difference / _A_MINUTE, time_difference / _A_MINUTE));
    else if (time_difference < 24 * _AN_HOUR)
        return res.getString(R.string.time_ago,
                             res.getQuantityString(R.plurals.hours, (int) time_difference / _AN_HOUR, time_difference / _AN_HOUR));
    else if (time_difference < 48 * _AN_HOUR)
        return res.getString(R.string.yesterday);
    else
        return res.getString(R.string.time_ago,
                             res.getQuantityString(R.plurals.days, (int) time_difference / _A_DAY, time_difference / _A_DAY));
}

我将常量定义为：

/** One second (in milliseconds) */
private static final int _A_SECOND = 1000;
/** One minute (in milliseconds) */
private static final int _A_MINUTE = 60 * _A_SECOND;
/** One hour (in milliseconds) */
private static final int _AN_HOUR = 60 * _A_MINUTE;
/** One day (in milliseconds) */
private static final int _A_DAY = 24 * _AN_HOUR;

然后剩下的工作是复数和字符串资源的结构。

我的默认本地是en，所以res/values/strings.xml：

<!-- time ago strings -->
<string name="just_now">just now</string>
<string name="time_ago">%s ago</string>
<string name="yesterday">yesterday</string>

然后res/values/plurals.xml：

<plurals name="minutes">
    <item quantity="one">a minute</item>
    <item quantity="other">%d minutes</item>
</plurals>

<plurals name="hours">
    <item quantity="one">an hour</item>
    <item quantity="other">%d hours</item>
</plurals>

<plurals name="days">
    <item quantity="one">a day</item>
    <item quantity="other">%d days</item>
</plurals>

这种方法应该允许你定位语言的词汇和语法，因为不同的语言不仅对于像“分钟”这样的单词有不同的单词，而且它们对于如何根据数量复数单词也有不同的规则。因此，复数资源利用Android框架支持多元化本地化。剩下的就是提供翻译。

答案 2 :(得分：1)

这个答案类似于丹德尔的回答，除了：

  • 昨天是根据日历时间而不是秒来定义的。
    • 例如，当：
      • 发布时间晚上10:00:00 2015年1月19日
      • 且当前时间 01：00：00. 01/20/20
    • 格式化日期应打印：昨天而不是 3小时前

首先，让我们编写返回格式化日期的主函数：

public String getStringFormattedDate(Context context, Date postDate){
    Calendar postCalendar = Calendar.getInstance();
    postCalendar.setTime(postDate);
    Calendar currentCalendar = Calendar.getInstance();

    long delta = Math.abs(currentCalendar.getTimeInMillis() - postCalendar .getTimeInMillis()) / 1000;

    //**yesterday**
    //This has to be checked first, otherwise, yesterday logic 
    //will be overridden by "seconds ago", "minutes ago", "hours ago"
    if(isYesterday(postCalendar , currentCalendar)){
        return context.getResources().getString(R.string.yesterday);
    }
    //seconds ago
    else if (delta < 60)
    {
        return context.getResources().getQuantityString(R.plurals.seconds, (int)delta, (int)delta);
    }
    //minutes ago
    else if (delta < 3600) // 60 * 60
    {
        delta /= 60.0; // convert seconds to minutes
        return context.getResources().getQuantityString(R.plurals.minutes, (int)delta, (int)delta);
    }
    //hours ago
    else if (delta < 86400) // 24 * 60 * 60
    {
        delta /= (60.0*60.0); // convert seconds to hours
        return context.getResources().getQuantityString(R.plurals.hours, (int)delta, (int)delta);
    }
    //older dates
    else{
       delta /= (60.0*60.0*24.0); // convert seconds to days
       return context.getResources().getString(R.string.time_ago, context.getResources().getQuantityString(R.plurals.days, (int) delta , (int) delta));
    }
}

函数isYesterday()，用于检查postCalendar昨天是否与当前日历进行比较：

//return true, if postCalendar is a day behind currentCalendar
private boolean isYesterday(Calendar postCalendar, Calendar currentCalendar){
    Calendar cloneCurrentCalendar = (Calendar) currentCalendar.clone();
    resetTime(cloneCurrentCalendar);

    Calendar clonePostCalendar = (Calendar) postCalendar.clone();
    resetTime(clonePostCalendar);
    clonePostCalendar.add(Calendar.DAY_OF_MONTH, 1);

    return (cloneCurrentCalendar.compareTo(clonePostCalendar) == 0);
}

重置日历实例的函数resetTime()，仅用于比较日历日期：

//set Time to 00:00:00
private void resetTime(Calendar calendar){
    calendar.set(Calendar.MILLISECOND, 0);
    calendar.set(Calendar.SECOND, 0);
    calendar.set(Calendar.MINUTE, 0);
    calendar.set(Calendar.HOUR_OF_DAY, 0);
}

答案 3 :(得分：0)

我在答案中略微编辑了代码。我得到了＃0; 0小时前＆＃34;字符串，由long和int的划分引起的。此外，答案中缺少private static Class<Math> Math; for (PropertyDescriptor propertyDescriptor : Introspector.getBeanInfo(Math).getPropertyDescriptors()) { System.out.println(propertyDescriptor.getReadMethod()); } 方法，因此我使用getCurrentTime()。这是我的修改，它解决了System.getCurrentTimeInMillis()问题。

0 hour ago

public static String getTimeAgo(long time, Context context) { if (time < 1000000000000L) { // if timestamp given in seconds, convert to millis time *= 1000; } final long now = System.currentTimeMillis(); if (time > now || time <= 0) return ""; final Resources res = context.getResources(); final long time_difference = now - time; if (time_difference < C._A_MINUTE) return res.getString(R.string.just_now); else if (time_difference < 50 * C._A_MINUTE) return res.getString(R.string.time_ago, res.getQuantityString(R.plurals.minutes, (int) time_difference / C._A_MINUTE, time_difference / C._A_MINUTE)); else if (time_difference < 24 * C._AN_HOUR) return res.getString(R.string.time_ago, res.getQuantityString(R.plurals.hours, (int) Math.ceil((double)time_difference / C._AN_HOUR), time_difference / C._AN_HOUR)); else if (time_difference < 48 * C._AN_HOUR) return res.getString(R.string.yesterday); else return res.getString(R.string.time_ago, res.getQuantityString(R.plurals.days, (int) Math.ceil((double)time_difference / C._A_DAY), time_difference / C._A_DAY)); } 是我保持常量的地方。这是：

C.java

其他文件（public class C { /** One second (in milliseconds) */ public static final int _A_SECOND = 1000; /** One minute (in milliseconds) */ public static final int _A_MINUTE = 60 * _A_SECOND; /** One hour (in milliseconds) */ public static final int _AN_HOUR = 60 * _A_MINUTE; /** One day (in milliseconds) */ public static final int _A_DAY = 24 * _AN_HOUR; 和plurals.xml）相同。请参阅上面的答案。

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