如何格式化用户区域设置的当前日期？

I have this code where I'm trying to get the current date and format it in the current locale.

我有这个代码,我正在尝试获取当前日期并在当前语言环境中格式化它。

NSDate *now = [NSDate date];  //  gets current date
NSString *sNow = [[NSString alloc] initWithFormat:@"%@",now];
NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
[formatter setDateFormat:@"mm-dd-yyyy"];
insertCmd = [insertCmd stringByAppendingString: formatter setDateFormat: @"MM.dd.yyyy"];

I know the last line is wrong, but can't seem to figure it out... "insertCmd" is a NSString that I'm building for a FMDB command.

我知道最后一行是错误的,但似乎无法弄清楚......“insertCmd”是我正在为FMDB命令构建的NSString。

Help would be greatly appreciated, or a pointer to the "doc" where it's described.

非常感谢帮助,或指向描述它的“doc”的指针。

3 个解决方案

#1

I wouldn't use setDateFormat in this case, because it restricts the date formatter to a specific date format (doh!) - you want a dynamic format depending on the user's locale.

在这种情况下我不会使用setDateFormat,因为它将日期格式化程序限制为特定的日期格式(doh!) - 您需要一种动态格式,具体取决于用户的语言环境。

NSDateFormatter provides you with a set of built-in date/time styles that you can choose from, i.e. NSDateFormatterMediumStyle, NSDateFormatterShortStyle and so on.

NSDateFormatter为您提供了一组可供选择的内置日期/时间样式,即NSDateFormatterMediumStyle,NSDateFormatterShortStyle等。

So what you should do is:

所以你应该做的是:

NSDate* now = [NSDate date];
NSDateFormatter* df = [[NSDateFormatter alloc] init];
[df setDateStyle:NSDateFormatterMediumStyle];
[df setTimeStyle:NSDateFormatterShortStyle];
NSString* myString = [df stringFromDate:now];

This will provide you with a string with a medium-length date and a short-length time, all depending on the user's locale. Experiment with the settings and choose whichever you like.

这将为您提供具有中等长度日期和短时长度的字符串,所有这些都取决于用户的区域设置。尝试设置并选择您喜欢的任何一个。

Here's a list of available styles: https://developer.apple.com/library/mac/#documentation/Cocoa/Reference/Foundation/Classes/NSDateFormatter_Class/Reference/Reference.html#//apple_ref/c/tdef/NSDateFormatterStyle

以下是可用样式列表:https://developer.apple.com/library/mac/#documentation/Cocoa/Reference/Foundation/Classes/NSDateFormatter_Class/Reference/Reference.html#//apple_ref/c/tdef/NSDateFormatterStyle

#2

In addition to jiayow answer you can specify your custom 'template' to get localized version:

除了jiayow回答,您还可以指定自定义“模板”以获取本地化版本:

+ (NSString *)formattedDate:(NSDate *)date usingTemplate:(NSString *)template {
    NSDateFormatter* formatter = [NSDateFormatter new];

    formatter.dateFormat = [NSDateFormatter dateFormatFromTemplate:template options:0 locale:formatter.locale];

    return [formatter stringFromDate:date];
}

Example usage for US/DE locale:

US / DE语言环境的示例用法:

NSLocale *enLocale = [NSLocale localeWithLocaleIdentifier:@"en_US"];
NSLocale *deLocale = [NSLocale localeWithLocaleIdentifier:@"de"];

// en_US:   MMM dd, yyyy
formatter.dateFormat = [NSDateFormatter dateFormatFromTemplate:@"ddMMMyyyy" options:0 locale:enLocale];
// de:      dd. MMM yyyy
formatter.dateFormat = [NSDateFormatter dateFormatFromTemplate:@"ddMMMyyyy" options:0 locale:deLocale];

// en_US:   MM/dd/yyyy
formatter.dateFormat = [NSDateFormatter dateFormatFromTemplate:@"ddyyyyMM" options:0 locale:enLocale];
// de:      dd.MM.yyyy
formatter.dateFormat = [NSDateFormatter dateFormatFromTemplate:@"ddyyyyMM" options:0 locale:deLocale];

// en_US    MM/dd
formatter.dateFormat = [NSDateFormatter dateFormatFromTemplate:@"MMdd" options:0 locale:enLocale];
// de:      dd.MM.
formatter.dateFormat = [NSDateFormatter dateFormatFromTemplate:@"MMdd" options:0 locale:deLocale];

#3

If you want the localized date and time this will give it to you:

如果您想要本地化的日期和时间,这将给您:

    NSString *localizedDateTime = [NSDateFormatter localizedStringFromDate:[NSDate date] dateStyle:NSDateFormatterShortStyle timeStyle:NSDateFormatterShortStyle];

The code above does not give you the localized date and time.

上面的代码没有为您提供本地化的日期和时间。

#1