最下方有翻译总结
1.原文连结：
https://bit.ly/3CKhzuF
2.原文标题：
第三方App动画在iPhone 13 Pro上最高只能用60Hz更新率
Third-party apps limited to 60Hz animations on iPhone 13 Pro
3.原文来源(媒体/作者)：
9to5mac/Benjamin Mayo
4.原文内容：
Update: Apple has officially responded that some of the behaviours described bel
ow are the result of an OS bug. Full support for 120Hz in third-party apps is co
ming soon. Original story below.
One of the biggest new features exclusive to the iPhone 13 Pro and iPhone 13 Pro
Max this year is the inclusion of high-refresh rate displays, or what Apple cal
ls “ProMotion.”
That means the iPhone 13 Pro models feature new OLED displays that can refresh t
heir screen content at up to 120 times per second, or 120Hz. However, developers
receiving their phones today have discovered that, in many circumstances, their
animations can only run at 60Hz — the same as the cheaper iPhone 13 and iPhone
13 mini, as well as prior iPhone generations.
As it stands with iOS 15.0, ProMotion takes effect in third-party apps when scro
lling or doing full-screen transitions. That means that you will still get a ver
y fluid and responsive experience when scrolling your Twitter timeline, for inst
ance.
However, almost all other animations are capped at 60Hz in third-party apps. Thi
s includes special effects and animations for custom components. It can be parti
cularly jarring for the same third-party app to feature smooth scrolling but the
n less-smooth interaction experience elsewhere. Developer of the Apollo Reddit c
lient Christian Selig has already reported complaints about this from his custom
ers.
A workaround hidden plist-key has been discovered that lifts the limit for Scene
Kit and SpriteKit based applications, and Dice by PCalc developer James Thomson
is currently seeing if it will pass App Review. However, most animations in iOS
apps are driven by the Core Animation framework and remain limited to 60Hz, even
in the presence of this special undocumented plist entry.
Interestingly, these limits do not apply to third-party apps running on the iPad
Pro, which has featured a 120Hz display since 2017.
Apple appears to have specially carved out these restrictions for the new iPhone
models. One source suggested that this had been implemented for battery life re
asons. However, we don’t know for sure if that is the case.
Perhaps more conspiratorially, examination of iOS 15 code indicates that only th
ird-party apps are being constrained. Code in the OS exempts first-party Apple a
pps and allows them to run at full 120Hz animation speed all the time.
Apple touts ProMotion on the iPhone as an adaptive system that ramps up and ramp
s down depending on what the user is doing. For instance, if the screen is dorma
nt, the phone can lower itself to a 10Hz refresh rate to save power. However, cu
stomers and developers reasonably expected that app animations would be able to
take advantage of the 120Hz hardware for super fluid animations, just like they
can get with scrolling. Apple’s apps certainly seem allowed to do just that, as
all apps can on the iPad Pro, but not third-party apps on the iPhone 13.
It’s still possible this is all just a bug in the 15.0 implementation, but it s
adly seems unlikely in the presence of the code evidence. We’ve contacted Apple
about this situation for clarification and will update if we hear back.
5.心得/评论：
简短翻译如下
部份App开发人员发现第三方软件上的特效与动画只能上到60Hz，而非120Hz，这种情况可能
令人觉得打开App会有卡顿感。与此同时，iPad Pro上却没有此限制
苹果表示，所有第三方App皆可以充分利用120Hz ProMotion刷新率，但开发者需要新增新的
Info.plist key来声明他们的App需要使用更高的帧率。相关说明文件苹果官方会尽快释出
然后由Core Animation framework驱动的动画会经由后续更新使其上至120Hz更新率

才刚上市欸 等三个月再来吧