您的房子或工作区周围是否有备用的 Chromebook ？(a spare Chromebook)您可以将它用作 PC 的临时辅助显示器。独立显示器变得非常昂贵(monitors are becoming crazy expensive)，因此，如果您还买不起一台，请阅读本指南以了解如何将Chromebook用作第二台显示器。
ChromeOS没有可让您执行此操作的内置工具，因此您需要第三方解决方案。我们测试了一些（免费和付费）工具，但只找到了一个可靠的产品——Duet Display。
首先，我们应该提到Duet Display是一款付费应用（售价 9.99 美元）。您只需在Chromebook上购买(Chromebook)Android应用程序（从Google Play 商店(Google Play Store)）。Mac和Windows客户端是免费的——只要您是付费用户。
它还可以无线工作，因此您不需要任何电缆。但是，您的设备必须在同一个Wi-Fi网络上才能使应用程序正常工作。
在 Chromebook 上设置 Duet 显示
启动Play 商店(Play Store)，搜索Duet Display，然后单击安装(Install)以将应用程序下载到您的Chromebook上。
打开Duet Display，创建一个帐户（也在您的电子邮件中验证该帐户），然后单击连接(Connect)以将您的Mac或 Windows PC 的显示器链接到您的Chromebook。
该应用程序现在已准备好接收来自连接到您的Duet Air帐户的其他设备的视觉信号。下一步是在您的Mac或Windows计算机上设置Duet Display 。
在 Mac 上设置 Duet 显示
访问Duet Display 网站(Duet Display website)并单击macOS按钮下载应用程序客户端。在您的设备上安装该应用程序并继续下一步以将您的Chromebook用作第二台显示器。
如果您的Mac运行 macOS Catalina (10.15) 或更高版本，您需要授予 Duet Display “辅助功能”和屏幕(Screen)访问权限。转到系统偏好设置(System Preferences)>安全和隐私(Security & Privacy)>隐私(Privacy)>辅助功能(Accessibility)，然后单击窗口左下角的锁定图标。
检查Duet以授予应用程序访问权限以控制您的Mac。
接下来，用于屏幕录制访问；选择侧边栏上的屏幕录制(Screen Recording)并检查二重奏(duet)。
虽然您可以在没有帐户的情况下使用 Dual Display 的Mac客户端，但登录您的Duet 帐户(Duet Account)可以确保与您的Chromebook进行更安全、更快速的连接。因此，我们建议您登录您的Duet Air帐户；启动应用程序并单击登录远程桌面(Sign In For Remote Desktop)。
您需要做的最后一件事是：在Duet应用程序中启用屏幕共享。单击侧边栏上的(Click) 配置文件(Profile)并选中启用屏幕共享(Screen Sharing Enabled)。
您现在可以继续使用该应用程序将 Mac 的显示投影或扩展到Chromebook。
(Use Chromebook)在Mac上(Mac)使用 Chromebook作为第二台显示器(Second Monitor)
确保(Make)Duet Display(Duet Display)具有正常工作所需的权限。同样(Likewise)，确保您将设备连接到同一个Wi-Fi网络。
1. 在您的Chromebook(Chromebook)上启动Duet应用程序。
2. 在您的Mac(Mac)上打开应用程序并转到Android选项卡。
该应用程序应自动检测连接到 Wi-Fi 网络的Chromebook或其他“Duet Air”设备。
3. 当您的 Chromebook 出现在“发现的(Discovered) 设备(Devices)”部分时，点击单击以无线连接(Click to connect wirelessly)。
如果应用未自动检测您的Chromebook，请选择手动连接到 IP(Connect to IP Manually)，输入您的 Chromebook 的 IP 地址并选择连接(Connect)。
您可以在Settings > Network > Connected network > IP Address中找到 Chromebook 的 IP 地址。
4. Duet让你镜像和扩展你的Mac的显示。如果您的Mac有触控栏(Touch Bar)，您可以轻松地在“镜像显示”或“扩展桌面”模式之间切换。
要在非 Touch Bar Mac(Bar Macs)上切换显示模式，请转到 Duet 的设置，选择调整设置(Adjust Settings)并选中镜像显示(Mirror Display)。
切换显示模式的另一种方法是单击Mac菜单栏上的镜像图标，然后选择Mirror Built-in Retina Display。
要将应用程序或窗口移动到 Chromebook 的显示屏，请将应用程序拖到 Mac 屏幕的右边缘。应用程序窗口将从显示屏的左边缘出现在您的 Chromebook 上。
如果您想修改或更改屏幕位置，请转到系统偏好设置(System Preferences)>显示(Displays)>排列(Arrangement)并将显示（蓝色矩形）拖动到不同的位置。有趣的是，您也可以只移动菜单栏；将显示屏顶部的白色矩形拖到第二个屏幕。
无论您是镜像还是扩展您的显示器，Duet都足够智能，可以检测您的Mac或 PC 的键盘和触控板。如果您愿意，还可以使用 Chromebook 的键盘或触控板。
在 Windows 上设置 Duet 显示
访问Duet Display 网站(Duet Display website)并下载Windows安装客户端。安装应用程序并重新启动计算机。将您的 PC 连接到与Chromebook相同的(Chromebook)Wi-Fi网络并启动Duet。
转到Air选项卡并单击登录以进行远程访问(Sign In For Remote Access)以连接您的 Dual Air 帐户。
接下来，转到Profile选项卡并选中Screen Sharing Enabled。
最后，转到Settings选项卡并选中Enable Duet Air。
现在一切就绪，可以将Chromebook用作 PC 的第二个显示器。
(Use Chromebook)在Windows上(Windows)使用 Chromebook作为第二个显示器(Second Monitor)
注意：(Note:)虽然Duet支持Windows，但该应用程序在Mac上运行得更好更流畅。该应用程序偶尔会在我们的测试Windows(Windows) PC上崩溃，尤其是在连接到Chromebook之后。有时，除非我们重新启动 PC，否则它不会打开。根据我们的研究，其他一些Windows用户也无法在他们的设备上流畅地使用该应用程序，但其他一些用户却可以正常运行。
这可能是由于不同的硬件配置造成的。或者，可能是Windows客户端中的错误。在您的Windows(Windows) PC上试用该应用程序，让我们知道您的体验。
如果您正确配置了应用程序，Windows 上的Duet应用程序应该会立即自动检测您的Chromebook。否则，请关闭并重新打开应用程序，或重新启动计算机。
在Air选项卡中，选择侧边栏上的Android并单击您的Chromebook。如果您仍然无法在已发现设备列表中找到您的Chromebook，请单击手动连接到 IP(Connect to IP Manually)并输入您的 Chromebook 的 IP 地址。
转到设置(Settings)>网络(Network)>连接的网络(Connected network)> IP 地址(IP Address)以检查您的Chromebook的 IP。您的 PC 桌面应该出现在Chromebook上。
重要的二重奏显示设置
在将您的显示器投影或镜像到Chromebook时，您会在应用程序的设置(Settings)页面上找到一些重要的配置。以下是它们的含义以及它们如何影响您使用该应用程序的体验：
1. 文字大小：(1. Text Size:)有五种文字大小可供选择。文字越大，Chromebook上的显示分辨率就越小。
2. Retina Display：如果您选中Retina选项，Duet将通过将像素密度加倍来模拟 Chromebook 上的视网膜显示。虽然此设置会提高图片质量，但它会导致应用程序消耗更多的电池电量。
3. 帧率：(3. Framerate:)有两种选择：60 FPS和30 FPS。选择更高的帧速率(higher frame rate)将提供更流畅的运动，但会以设备电池为代价。
4. 质量：(4. Quality:) Duet还让您可以自由选择您喜欢的信号传输质量。高质量(High)以更少的数字伪影提供最佳体验。在常规(Regular)质量上，文本和图像将具有更多细节。此外，该应用程序将消耗更少的电池电量。
当您更改任何这些设置时， Duet应用程序会自动调整 Chromebook 的显示。为获得最佳体验，我们建议使用可用的最高设置。但是，请确保在使用该应用程序时将设备插入电源。
调节开关
您还可以使用Duet应用程序将(Duet)Chromebook的屏幕无线投影到Mac或Windows PC。将设备连接到同一Wi-Fi网络并启动Duet Display。您的Mac或Windows PC应出现在Chromebook上的应用程序仪表板上；选择镜像(Mirror)或扩展(Extend)以相应地投影您的屏幕。
如果您有任何问题，请发表评论或访问Duet Display 帮助中心(Duet Display Help Center)寻求帮助。
How to Use Your Chromebook as a Second Monitor
Do you have a spare Chromebook lying around the house or your workspace? You can put it to good use as a makeshift secondary monitor for your PC. Standalone monitors are becoming crazy expensive, so if you cannot afford one just yet, read this guide to learn how to use your Chromebook as a second monitor.
ChromeOS doesn’t have a built-in tool that lets you do this, so you’ll need third-party solutions. We tested a handful of (free and paid) tools but only found one reliable product—Duet Display.
Before anything, we should mention that Duet Display is a paid app (costs $9.99). You’ll only need to purchase the Android app on your Chromebook (from the Google Play Store). The Mac and Windows clients are free—as long as you’re a paid user.
It also works wirelessly so you don’t need any cable. However, your devices must be on the same Wi-Fi network for the app to work.
Set Up Duet Display on Chromebook
Launch the Play Store, search for Duet Display, and click Install to download the app on your Chromebook.
Open Duet Display, create an account (verify the account in your email, too) and click Connect to link your Mac or Windows PC’s display to your Chromebook.
The app is now ready to receive visual signals from other devices connected to your Duet Air account. The next step is to set up Duet Display on your Mac or Windows computer.
Set Up Duet Display on Mac
Visit the Duet Display website and click the macOS buttons to download the app client. Install the app on your device and proceed to the next step to use your Chromebook as a second monitor.
If your Mac runs macOS Catalina (10.15) or later, you’ll need to grant the Duet Display “Accessibility” and Screen access. Go to System Preferences > Security & Privacy > Privacy > Accessibility and click the lock icon at the window’s bottom-left corner.
Check duet to grant the app access to control your Mac.
Next, for screen recording access; select Screen Recording on the sidebar and check duet.
Although you can use the Dual Display’s Mac client without an account, signing into your Duet Account allows for a secured and faster connection with your Chromebook. Therefore, we recommend signing in to your Duet Air account; launching the app and clicking Sign In For Remote Desktop.
There’s one last thing you need to do: enable screen sharing within the Duet app. Click Profile on the sidebar and check Screen Sharing Enabled.
You can now proceed to use the app to project or extend your Mac’s display to your Chromebook.
Use Chromebook as Second Monitor on Mac
Make sure Duet Display has the necessary permissions to work correctly. Likewise, ensure you connect your devices to the same Wi-Fi network.
1. Launch the Duet app on your Chromebook.
2. Open the app on your Mac and go to the Android tab.
The app should automatically detect your Chromebook or other “Duet Air” devices connected to your Wi-Fi network.
3. When your Chromebook shows up in the “Discovered Devices” section, tap Click to connect wirelessly.
If the app isn’t detecting your Chromebook automatically, select Connect to IP Manually, enter your Chromebook’s IP address and select Connect.
You’ll find your Chromebook’s IP address in Settings > Network > Connected network > IP Address.
4. Duet lets you mirror and extend your Mac’s display. If your Mac has a Touch Bar, you can easily toggle between both the “Mirror Displays” or “Extend Desktop” modes.
To switch display mode on non-Touch Bar Macs, go to Duet’s settings, select Adjust Settings and check Mirror Display.
Another way to switch display modes is to click the mirroring icon on the Mac menu bar and select Mirror Built-in Retina Display.
To move an app or window to the Chromebook’s display, drag the app to the right edge of your Mac’s screen. The app window will appear on your Chromebook from the left edge of the display.
If you wish to modify or alternate the screen positions, go to System Preferences > Displays > Arrangement and drag the display (blue rectangle) to a different position. Interestingly, you can also move the menu bar only; drag the white rectangle at the top of the display to the second screen.
Whether you’re mirroring or extending your display, Duet is smart enough to detect your Mac or PC’s keyboard and trackpad. You can also use the Chromebook’s keyboard or trackpad if you wish.
Set Up Duet Display on Windows
Visit the Duet Display website and download the Windows setup client. Install the app and restart your computer. Connect your PC to the same Wi-Fi network as the Chromebook and launch Duet.
Go to the Air tab and click Sign In For Remote Access to connect your Dual Air account.
Next, go to the Profile tab and check Screen Sharing Enabled.
Finally, go to the Settings tab and check Enable Duet Air.
Everything’s now in order to use your Chromebook as a second display for your PC.
Use Chromebook As Second Monitor on Windows
Note: Although Duet supports Windows, the app worked better and smoother on Mac. The app occasionally crashed on our test Windows PC, particularly after connecting to a Chromebook. Sometimes, it wouldn’t open unless we rebooted our PC. From our research, a couple of other Windows users were also unable to use the app smoothly on their devices, but a few others got it working without issues.
This may be due to varying hardware configurations. Or perhaps, a bug in the Windows client. Give the app a try on your Windows PC and let us know your experience.
If you configured the app correctly, the Duet app on your Windows should automatically detect your Chromebook immediately. Otherwise, close and reopen the app, or restart your computer.
In the Air tab, select Android on the sidebar and click your Chromebook. If you still can’t find your Chromebook on the list of discovered devices, click Connect to IP Manually and enter your Chromebook’s IP address.
Go to Settings > Network > Connected network > IP Address to check your Chromebook’s IP. Your PC’s desktop should appear on the Chromebook.
Important Duet Display Settings
While projecting or mirroring your display to the Chromebook, you’ll find a couple of important configurations on the app’s Settings page. Here’s what they mean and how they can impact your experience using the app:
1. Text Size: There are five text sizes to choose from. The larger the text size, the smaller the display resolution on your Chromebook.
2. Retina Display: If you check the Retina option, Duet will simulate a retina display on your Chromebook by doubling the pixel density. While this setting will improve picture quality, it’ll cause the app to consume more battery power.
3. Framerate: There are two options: 60 FPS and 30 FPS. Choosing the higher frame rate will provide smoother motion, but at the expense of your device’s battery.
4. Quality: Duet also hands you the freedom to choose your preferred signal transmission quality. High quality provides the best experience with fewer digital artifacts. On Regular quality, texts and images will have more detail. Plus, the app will consume less battery power.
The Duet app automatically adjusts your Chromebook’s display when you change any of these settings. For the best experience, we recommend the highest settings available. However, make sure you plug your devices into a power source when using the app.
Flip the Switch
You can also use the Duet app to wirelessly project your Chromebook’s screen to a Mac or Windows PC. Connect the devices to the same Wi-Fi network and launch Duet Display. Your Mac or Windows PC should appear on the app’s dashboard on your Chromebook; select Mirror or Extend to project your screen accordingly.
If you have any questions, drop a comment or visit the Duet Display Help Center for assistance.
