Apple released iOS 11 on September 19, 2017. You can upgrade by tapping “Install Now” when an update message appears, but you can also check for the update and install it immediately.

苹果于2017年9月19日发布了iOS11 。您可以通过在出现更新消息时点按“立即安装”来进行升级，但是您也可以检查更新并立即安装。

iOS 11 is available for the iPhone 7 Plus, iPhone 7, iPhone 6s, iPhone 6s Plus, iPhone 6, iPhone 6 Plus, iPhone SE, and iPhone 5s. It’s also available for the iPad Pro (all of them), iPad (5th generation), iPad Air 2, iPad Air, iPad mini 4, iPad mini 3, iPad mini 2, and iPod touch (6th generation).

iOS 11适用于iPhone 7 Plus，iPhone 7，iPhone 6s，iPhone 6s Plus，iPhone 6，iPhone 6 Plus，iPhone SE和iPhone 5s。 它还适用于iPad Pro(所有产品)，iPad(第五代)，iPad Air 2，iPad Air，iPad mini 4，iPad mini 3，iPad mini 2和iPod touch(第六代)。

选项一：从设备无线更新 (Option One: Update Wirelessly from Your Device)

First, ensure you have enough power to update. You need at least 50% battery available on your device to start the update, although Apple recommends you connect your device to a power outlet while updating.

首先，请确保您有足够的能力进行更新。 尽管Apple建议您在更新时将设备连接至电源插座，但是您至少需要50％的电池电量来启动更新。

You’ll also need to connect your device to Wi-Fi, as you can’t install big updates like iOS 11 over a cellular connection.

您还需要将设备连接到Wi-Fi，因为您无法通过蜂窝连接安装iOS 11等大型更新。

Tap Settings > General > Software Update to check for the update. Your device will check for any updates you can install. Tap “Download and Install” to start the installation process.

点击设置>常规>软件更新以检查更新。 您的设备将检查您可以安装的所有更新。 点击“下载并安装”开始安装过程。

The iOS 11 update needs at least 2 GB of free space on your device to download and install. If not enough space is available, your device will offer to temporarily remove apps to make space. Tap “Continue” and it will remove the apps (but not your data), install the update, and then restore the apps it removed. It works a lot like the app offloading feature. You can also tap “Cancel” and free up space on your iPhone or iPad in any way you like before continuing.

iOS 11更新需要在您的设备上至少有2 GB的可用空间才能下载和安装。 如果没有足够的空间，您的设备将提供临时删除应用程序以腾出空间的功能。 点击“继续”，它将删除应用程序(但不删除您的数据)，安装更新，然后恢复其删除的应用程序。 它的工作原理与应用程序分载功能非常相似。 您也可以轻按“取消”，然后以任意方式释放iPhone或iPad上的空间，然后再继续。

If there’s enough free space available, your device will offer to download the update. Tap “Install” to update now. You can also tap “Later” and then “Install Tonight”. Connect your device to power when you go to sleep at night and it will automatically install the update overnight.

如果有足够的可用空间，您的设备将提供下载更新。 点击“安装”以立即更新。 您也可以点击“稍后”，然后点击“今晚安装”。 晚上睡觉时，将设备接通电源，它将在一夜之间自动安装更新。

Finally, you’ll be asked to enter your device’s passcode. Enter it and the update process will begin. If you don’t know your passcode, you’ll have to wipe your device and start from scratch.

最后，系统会要求您输入设备的密码。 输入它，更新过程将开始。 如果您不知道密码，则必须擦除设备并从头开始。

选项二：插入计算机并使用iTunes更新 (Option Two: Plug Into Your Computer and Update Using iTunes)

You can still use iTunes to update an iPhone, iPad, or iPod Touch. It’s normally more convenient to update wirelessly using the device itself, but iTunes can come in handy in rare situations. For example, if you don’t have a Wi-Fi network available but you have a computer with a wired Ethernet connection, you can plug your device into the computer and use iTunes to download the update.

您仍然可以使用iTunes更新iPhone，iPad或iPod Touch。 使用设备本身进行无线更新通常更方便，但是iTunes在极少数情况下可以派上用场。 例如，如果您没有可用的Wi-Fi网络，但有一台具有有线以太网连接的计算机，则可以将设备插入计算机并使用iTunes下载更新。

You’ll need the latest version of iTunes to do this. On a PC, either launch iTunes and click Help > Check for Updates, or download iTunes from Apple if you don’t already have it installed. On a Mac, open iTunes and click iTunes > Check for Updates.

您需要最新版本的iTunes才能执行此操作。 在PC上，启动iTunes并单击“帮助”>“检查更新”，或者如果尚未安装，请从Apple下载iTunes。 在Mac上，打开iTunes，然后单击iTunes>检查更新。

Once the latest version is installed, connect your device to your PC or Mac using its included cable—the same one you use to charge it. Select your device by clicking its icon on the toolbar at the upper left corner of the iTunes window.

安装最新版本后，使用随附的电缆将设备连接至PC或Mac(用于充电)。 通过单击iTunes窗口左上角工具栏上的设备图标来选择您的设备。

Click the “Summary” heading in the sidebar and then click the “Check for Update” button under the device’s name in the main pane. iTunes will check for any available updates and prompt you to install them.

单击边栏中的“摘要”标题，然后在主窗格中单击设备名称下方的“检查更新”按钮。 iTunes将检查是否有可用的更新，并提示您安装它们。

Click “Download and Update” to install the update if it’s available. Enter your passcode on your device’s screen when it’s requested and the update will begin.

单击“下载并更新”以安装更新(如果有)。 根据要求在设备屏幕上输入密码，更新将开始。

翻译自: https://www.howtogeek.com/327329/how-to-update-your-iphone-or-ipad-to-ios-11/