如何在 iphone 应用程序中以纳秒为单位设置 NSTimer 时间间隔 [英] How to set NSTimer time interval in nano seconds in iphone app

问题描述

我正在制作一个一秒后调用方法的应用.

I am making an app calling methods after one second.

[NSTimer scheduledTimerWithTimeInterval:1.0 
                                 target:self 
                               selector:@selector(loadNews) 
                               userInfo:nil 
                                repeats:NO];

如何称呼这个

推荐答案

您的问题不完整.但是使用标题，我可以说您不能将 NSTimer 设置为纳秒之类的任何内容，并期望请求以您希望的方式得到尊重.

Your question is incomplete. However using the title, I can say that you cannot set the NSTimer to anything like nano-seconds and expect the request be honored in the way you hope.

它出现的最小间隔是 0.1 毫秒(或 0.0001 秒).api 文档 指出:

The smallest interval that it appears it can be set to is 0.1 milliseconds (or 0.0001 seconds). The the api documentation states:

计时器两次触发之间的秒数.如果间隔小于或等于 0.0，则此方法选择非负值 0.1 毫秒.

The number of seconds between firings of the timer. If interval is less than or equal to 0.0, this method chooses the nonnegative value of 0.1 milliseconds instead.

这意味着但没有明确定义最小值为 0.1 毫秒.

Which implies but does not definitely define the smallest value to be 0.1ms.

您应该注意，与许多计算机操作系统计时器一样 - 这是最短时间而不是最长时间 - 如果系统忙于做其他事情，不能保证它不会持续更长时间.与 Windows、MacOS 或 Linux 类似的 iOS 并不是一个实时操作系统"，其设计的目的是事件的时间线对应用程序的成功至关重要.

You should note that like with many computer operating system timers - this is a minimum time not a maximum - there is no guarantee that it will not go for longer if the system is busy doing something else. iOS like Windows or MacOS or Linux is not a 'real time operating system' designed where timelines of events is paramount to the success of the application.

尝试将计时器设置为 1 纳秒级别或 0.000000001 秒是行不通的.

Trying to set a timer to 1 nano second level, or 0.000000001 seconds is just not going to work.

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