ios12.3beta2
So you’ve installed the iOS 12 beta and, well, you’re experiencing some bugs. That’s okay, because you can quickly downgrade to the stable iOS 11.4.1.
因此，您已经安装了iOS 12 beta ，而且，您遇到了一些错误。 没关系，因为您可以快速降级到稳定的iOS 11.4.1。
让我们从一些警告开始 (Let’s Start with a Few Warnings)
Downgrading will completely wipe your iPhone or iPad, and that can present a problem. Let’s say you didn’t follow our advice to do a full backup before installing the iOS 12 beta. In that case, if you downgrade to iOS 11, you’re looking at a full device wipe and any data you don’t have backed up in another way (like photos copied to your computer outside of iTunes or iCloud) will be erased.
降级将完全擦除您的iPhone或iPad，这可能会带来问题。 假设您在安装iOS 12 Beta之前没有遵循我们的建议进行完整备份。 在这种情况下，如果您降级到iOS 11，则意味着正在擦除整个设备，并且您没有以其他方式备份的所有数据(例如复制到iTunes或iCloud之外的计算机上的照片)都将被删除。
And, even if you did back up your device while it was on iOS 11, any changes made or data created on your phone between the iOS 12 beta update and the rollback will be lost.
而且，即使您确实在iOS 11上备份设备时，在iOS 12 Beta更新和回滚之间所做的任何更改或在手机上创建的数据也将丢失。
If you were just playing around with the iOS 12 beta on a spare device, that’s not a big problem. If you installed the iOS 12 beta on your primary device and you didn’t back it up first, however, you might want to consider just sticking with iOS 12 to save yourself the lost data. It should get more and more stable as Apple releases new beta updates, anyway.
如果您只是在备用设备上玩iOS 12 Beta，那不是什么大问题。 如果您安装在主设备上iOS的12 beta和你没有备份了第一，但是，您可能要考虑只与iOS坚持12保存自己丢失的数据。 无论如何，随着Apple发布新的Beta更新，它应该变得越来越稳定。
Lastly, this tutorial will only help you downgrade from the iOS 12 beta to iOS 11 and it will only work up until the public release of iOS 12. After that, Apple will stop signing older iOS firmware versions and you will not be able to downgrade from iOS 12.
最后，本教程将仅帮助您从iOS 12 beta降级到iOS 11，并且仅在iOS 12公开发布之前可用。在那之后，Apple将停止对较旧的iOS固件版本进行签名，并且您将无法降级。从iOS 12。
Those cautions aside, let’s jump right into the pretty easy rollback process.
除了这些警告，让我们直接进入非常简单的回滚过程。
你需要什么 (What You Need)
To follow along today, you need just a few things. You’ll need your device, a USB data cable for said device, an up-to-date copy of iTunes, and you’ll need to download the appropriate iPSW file for your device. For the unfamiliar, iPSW files are the firmware files for iOS devices. Using an iPSW file to reset or restore your device is like performing a complete factory reset.
要跟随今天，您只需要注意几件事。 您将需要您的设备，用于该设备的USB数据线，iTunes的最新副本，并且需要为该设备下载适当的iPSW文件。 对于不熟悉的人，iPSW文件是iOS设备的固件文件。 使用iPSW文件重置或还原设备就像执行完整的出厂重置一样。
You can get the latest iPSW file for your device on a website like IPSW.me. This website links to the actual iPSW files on Apple’s servers, so you know your download is coming straight from Apple. Just select your device, and then download the latest signed iPSW file for it. You can only use signed iPSW files. At the time of writing, the latest version was iOS 11.4.1.
您可以在类似IPSW.me的网站上获取设备的最新iPSW文件。 该网站链接到Apple服务器上的实际iPSW文件，因此您知道您的下载直接来自Apple。 只需选择您的设备，然后为其下载最新的签名iPSW文件。 您只能使用签名的iPSW文件。 在撰写本文时，最新版本是iOS 11.4.1。
Unsure exactly which device you have? Check the model number on the case and use this iOS device list to make sure.
不确定到底拥有哪种设备？ 检查机壳上的型号并使用此iOS设备列表进行确认。
After carefully confirming which iPSW file you need for your device, download the file to your computer and head on to the next section.
在仔细确认设备所需的iPSW文件之后，将文件下载到计算机上并转到下一部分。
如何将设备回滚到iOS 11 (How to Roll Your Device Back to iOS 11)
First, if you’ve enabled the “Find My iPhone” feature for your iPhone or iPad, you will need to turn that feature off. You must do this from the iPhone or iPad itself. Head to Settings > [Your Name] > iCloud > Find My iPhone (or Find My iPad) and make sure the feature is turned off.
首先，如果您为iPhone或iPad启用了“查找我的iPhone”功能，则需要关闭该功能。 您必须从iPhone或iPad本身执行此操作。 转到设置> [您的名称]> iCloud>查找我的iPhone(或查找我的iPad)，并确保该功能已关闭。
With the iPSW file in hand, plug your iOS device into your PC or Mac with the USB cable, and then fire up iTunes. Inside iTunes, click on the device icon (located in the upper left corner and highlighted in the screenshot below).
手持iPSW文件后，使用USB电缆将iOS设备插入PC或Mac，然后启动iTunes。 在iTunes中，单击设备图标(位于左上角，并在下面的屏幕快照中突出显示)。
Within the device’s “Summary” page (the default view), locate the “Restore [Device Name]” button. Press and hold the Option key (Mac) or Shift key (Windows) and click the button. You must press the keyboard key while clicking the button in order to load the file browser to select a custom restore file. If you don’t, iTunes will only allow you to select from local backups you’ve made.
在设备的“摘要”页面(默认视图)中，找到“恢复[设备名称]”按钮。 按住Option键(Mac)或Shift键(Windows)，然后单击按钮。 您必须在单击按钮的同时按下键盘键，才能加载文件浏览器以选择自定义还原文件。 如果您不这样做，iTunes将仅允许您从制作的本地备份中进行选择。
When you click the Restore button, you won’t be prompted to back up your device, get any data off it, or warned in any fashion. The presumption is that, because you know this super secret key combination, you know what you’re doing.
单击“还原”按钮时，不会提示您备份设备，获取任何数据或以任何方式发出警告。 假设是，因为您知道此超级**组合，所以您知道自己在做什么。
In the file browser that pops up, navigate to the iPSW file for your device in the location you saved the download. Select it (if you have multiple devices, make sure you select the correct one for the device you’re currently wiping and restoring), and then click “Open” to start the process.
在弹出的文件浏览器中，在保存下载的位置导航到设备的iPSW文件。 选择它(如果有多个设备，请确保为当前要擦除和还原的设备选择正确的设备)，然后单击“打开”以开始该过程。
Click “Restore” to continue and erase the contents of your iPhone or iPad.
单击“还原”以继续并擦除iPhone或iPad的内容。
If you see an error message instead, you probably downloaded the wrong iPSW file for your device.
如果看到错误消息，则可能是设备下载了错误的iPSW文件。
Once you click that “Restore” button, it’s go time: your iOS device will be wiped and the iOS software will be downgraded from iOS 12 Beta to the latest version of iOS 11. When the process is finished, your device will boot back up as if you’d just turned it on for the first time—welcome screen and all. At that point, you can either start with a totally fresh copy of iOS 11 or you can copy your old iOS 11 backup (if you made one) from iTunes or iCloud.
单击该“恢复”按钮后，就可以了：您的iOS设备将被擦除，iOS软件将从iOS 12 Beta降级到最新版本的iOS11。完成该过程后，您的设备将重新启动就像您是第一次打开它一样-欢迎屏幕以及所有功能。 此时，您可以从全新的iOS 11副本开始，也可以从iTunes或iCloud复制旧的iOS 11备份(如果已创建)。
If you made a backup in iTunes, iTunes will ask you if you want to restore that backup to your device right after it finishes installing iOS 11. Select the backup and click “Continue” to do so.
如果您在iTunes中进行了备份，iTunes将在完成安装iOS 11后询问您是否要将备份还原到设备上。选择备份，然后单击“继续”。
At this point, be it with a fresh install or your old iOS 11 backup restored, you’re back on iOS 11 and can stay there as long as you want. However, you’ll probably want to upgrade to iOS 12 when the final, stable version is released later in 2018.
此时，无论是全新安装还是还原了旧的iOS 11备份，您都可以使用iOS 11，并可以在其中停留任意长时间。 但是，您可能要在2018年晚些时候发布最终的稳定版本时升级到iOS 12。
翻译自: https://www.howtogeek.com/359773/how-to-roll-back-to-ios-11-if-you’re-using-the-ios-12-beta/
ios12.3beta2