NSDateComponentsFormatter上的allowFractionalUnits我在做什么?

问题描述

基本上我想要的是获取仅以小时表示的时间间隔的值，而不是将其舍入为整小时(使用以获得正确的格式和本地化).我不知道是否误解了，但我无法让格式化程序为我提供一个十进制值.谁能帮助我发现我的错误，或以什么方式告诉我我对此有误解?

Basically what I want is to get the value of a time interval represented in hours only, without rounding it to full hours (using NSDateComponentsFormatter to get it properly formatted and localized). I don't know if I misunderstand the use of NSDateComponentsFormatter.allowsFractionalUnits, but I can't get the formatter to give me a decimal value. Can anyone help me spot my error or tell me in what way I misunderstand this?

从Apple文档中获取关于allowFractionalUnits属性的信息:

From Apple docs about allowsFractionalUnits property:

快速示例代码:

let formatter = NSDateComponentsFormatter()
formatter.unitsStyle = .Abbreviated
formatter.allowedUnits = .Hour
formatter.allowsFractionalUnits = true

let onePointFiveHoursInSeconds = NSTimeInterval(1.5 * 60.0 * 60.0)
print(formatter.stringFromTimeInterval(onePointFiveHoursInSeconds)!)
//"1h" instead of expected "1.5h"

Objective-C代码中的相同示例:

Same example in Objective-C code:

NSDateComponentsFormatter *formatter = [[NSDateComponentsFormatter alloc] init];
formatter.unitsStyle = NSDateComponentsFormatterUnitsStyleAbbreviated;
formatter.allowedUnits = NSCalendarUnitHour;
formatter.allowsFractionalUnits = YES;

NSTimeInterval onePointFiveHoursInSeconds = 1.5 * 60.0 * 60.0;
NSLog(@"%@", [formatter stringFromTimeInterval:onePointFiveHoursInSeconds]);
//"1h" instead of expected "1.5h"

更新:我已经向Apple报告了有关此问题的错误( rdar://22660145 ).

Update:I have reported a bug to Apple about this problem (rdar://22660145).

推荐答案

根据打开雷达#32024200 :

您没有做错任何事情.该标志只是坏了.

You're not doing anything wrong. The flag is simply broken.

这篇关于NSDateComponentsFormatter上的allowFractionalUnits我在做什么?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！