让 Mac 的屏幕共享功能正常工作至关重要。你永远不知道什么时候需要它。可以将您的 Mac 屏幕投影到第二台显示器(project your Mac’s screen to a second monitor)，或者与您的团队成员远程协作完成一个项目。
您应该能够毫无问题地与另一台Mac或其他设备共享您的屏幕。(Mac)但是，屏幕共享可能会突然停止在您的Mac上运行，无论是通过屏幕共享应用程序(screen-sharing apps)还是视频会议工具(video conferencing tools)（Skype、Zoom、Microsoft Teams等）。本文中的提示向您展示了如何解决该问题。
启用屏幕共享服务
您需要启用系统范围的屏幕共享(Screen Sharing)服务才能在其他设备上查看 Mac 的显示。打开系统偏好设置(System Preferences)，选择共享(Sharing)并检查屏幕共享(Screen Sharing)选项。
如果您的Mac仍未出现在其他设备上，请取消选择屏幕共享(Screen Sharing)并重新启用该功能。
禁用远程管理
macOS 具有远程管理(Remote Management)功能，可让您使用Apple 远程桌面(Apple Remote Desktop)应用程序从其他设备管理您的Mac。您不能在 macOS 上同时启用“屏幕共享(Screen Sharing)”和“远程管理”。(Remote Management)这是因为远程管理(Remote Management)工具控制了屏幕共享(Screen Sharing)服务。
如果您不使用Apple Remote Desktop应用程序，请禁用远程管理，以便您可以共享 MacBook 的屏幕。
转到系统偏好设置(System Preferences)>共享(Sharing)并取消选择远程管理(Remote Management)。
然后，检查屏幕共享(Screen Sharing)并检查您现在是否可以在其他设备上访问 Mac 的屏幕。
切换到管理员帐户
您需要管理权限才能使用 macOS屏幕共享(Screen Sharing)服务。如果您以访客(Guest)用户身份登录，请切换到管理员帐户。单击(Click)菜单栏(Menu Bar)上的帐户名称（电池图标旁边），选择管理员(Administrator)帐户，然后输入帐户密码（或使用 Touch ID）登录。
如果您在菜单栏上没有找到您的帐户名称，请转到系统偏好设置(System Preferences)> Dock & Menu Bar > Fast User Switching并选中Show in Menu Bar。
将您的设备连接到同一网络(Same Network)
要与另一台电脑共享 MacBook 的屏幕，您必须将两台设备连接到同一个网络。检查 Mac 的连接设置以确保您已正确连接到网络。
延长显示器休眠超时
如果任一设备进入睡眠状态，屏幕共享会话可能会突然结束。让您的Mac和其他设备保持唤醒状态，并确保它们不会进入睡眠模式。您可以调整Mac的电源设置，使其在屏幕共享期间不会进入睡眠状态。
1. 单击菜单栏上的电池图标并选择(battery icon)电池首选项(Battery Preferences)。
或者，前往System Preferences > Battery以访问MacBook上的(MacBook)Battery Preferences页面。
2. 默认情况下，macOS 会在 2 分钟不活动后关闭 Mac 的显示屏。将“关闭显示后(Turn display off after)”滑块向右移动以增加显示超时持续时间 — 可能为 30 分钟或更长时间。
3. 转到电源适配器(Power Adapter)选项卡并将显示超时调整为更长的时间。
如果您使用Mac桌面（i Mac或Mac Pro），请前往System Preferences > Energy Saver以访问Battery Preferences菜单。
注意：(Note:) 请记住在不使用(Remember)Mac Book 时始终合上盖子或将其置于睡眠状态。持续让显示器打开太久会缩短其电池寿命并可能损坏您的Mac。
启用屏幕录制访问
应用程序第一次尝试录制或共享Mac的屏幕时，会提示您授予应用程序屏幕录制权限。如果您拒绝该权限（可能是意外），屏幕共享将无法与Mac(Mac)上的应用程序一起使用。
1. 打开系统偏好设置(System Preferences)，选择安全和隐私(Security & Privacy)，前往隐私(Privacy)选项卡，然后选择侧边栏上的屏幕录制(Screen Recording)。
2. 单击左下角的锁定图标，输入您的 Mac 密码（或使用 Touch ID），并确保选择了受影响的应用程序。(lock icon)
如果您在框中找不到该应用程序，您可能拒绝该应用程序访问以记录您的屏幕。
3. 单击加号图标(plus icon)将应用程序添加到列表中。
4. 在 Finder 窗口中，转到Applications文件夹，选择要授予屏幕录制访问权限的应用程序，然后选择Open。之后(Afterward)，启动应用程序并再次尝试共享您的屏幕。
强制退出并重新启动应用程序
很多时候，强制关闭应用程序(force-closing an app)可以解决导致应用程序功能冻结或故障的问题。如果您无法在应用内使用屏幕共享，请强制退出应用并重试。
1. 按Command + Option + Escape打开“强制退出应用程序”窗口。或者，选择菜单栏上的Apple 标志并选择(Apple logo)Force Quit。
2. 选择有问题的应用程序，然后单击底部角落的强制退出按钮。(Force Quit)
3.在提示中选择强制退出。(Force Quit)
4. 重新启动应用程序并检查您现在是否可以毫无问题地共享您的 Mac 屏幕。
禁用或更改防火墙设置
内置的 macOS 防火墙提供了足够的保护，防止不必要的入侵。您不需要第三方防火墙软件(don’t need third-party firewall software)。除了减慢Mac的速度外，许多第三方防火墙还可以阻止屏幕共享和文件共享活动。如果您的Mac上安装了防火墙，请禁用该应用程序或确保它有权共享您的Mac屏幕。
您还应该检查内置 macOS 防火墙的配置，(configuration of the built-in macOS firewall)并确保受影响的应用程序具有屏幕共享访问权限。强制(Force)关闭应用程序并按照以下步骤操作。
1. 打开系统偏好设置(System Preferences)，选择安全和隐私(Security & Privacy)，进入防火墙(Firewall)选项卡，点击左下角的锁(lock icon)形图标并输入您的 Mac 密码或使用Touch ID进行身份验证。
2. 选择防火墙选项(Firewall Options)。
3. 确保取消选择“阻止(Block)所有传入连接。” 然后(” Afterward)，选中屏幕共享(Screen Sharing)框并将屏幕共享应用程序的权限设置为“允许传入连接(Allow incoming connections)”。如果应用程序被阻止共享您的 Mac 屏幕，请单击下拉按钮并选择允许传入连接(Allow incoming connections)。
4. 如果在防火墙选项(Firewall Options)中找不到受影响的应用程序，请单击“屏幕共享”框下方的加号图标，将屏幕共享应用程序列入白名单。(plus icon)
5. 在Applications文件夹中选择应用程序，然后单击Add。
6、最后选择确定(OK)保存防火墙权限。
重新启动你的 Mac
如果上述建议均未解决Mac屏幕共享无法正常工作，您应该重启Mac 。单击菜单栏上的Apple 标志并选择(Apple logo)重新启动(Restart)。
请务必在重新启动Mac之前关闭其他应用程序，以免丢失任何未保存的任务或文档。
更新应用程序
(Screen)如果尝试记录屏幕的应用程序已过时或有故障，屏幕共享可能无法正常工作。访问App Store、应用程序的设置菜单或开发者的网站，检查是否有适用于该应用程序的更新。安装最新版本的应用程序，然后再次尝试共享您的屏幕。
更新或升级您的 Mac
您还需要确保您的Mac是最新的。将您的Mac连接到互联网，转到系统偏好设置(System Preferences)>软件更新(Software Update)，然后单击立即更新(Update Now)（或立即升级(Upgrade Now)）按钮。
联系 Apple 支持
如果您的Mac(Mac)屏幕共享无法正常工作，这些故障排除提示无法解决这种罕见的情况，请访问附近的Genius Bar 天才吧(Genius Bar)或 Apple 认证的技术人员。
Mac Screen Sharing Not Working? 12 Ways to Fix
It’s essential to have your Mac’s screen sharing functionality working corrесtlу. You never know whеn you’ll need it. It could be to project your Mac’s screen to a second monitor or to collaborate with your teammate on a project remotely.
You should be able to share your screen with another Mac or other devices without issues. However, screen sharing can suddenly stop working on your Mac, either via screen-sharing apps or video conferencing tools (Skype, Zoom, Microsoft Teams, etc.). The tips in this article show you how to resolve the problem.
Enable the Screen Sharing Service
You need to have the system-wide Screen Sharing service enabled to view your Mac’s display on other devices. Open System Preferences, select Sharing and check the Screen Sharing option.
If your Mac still doesn’t show up on other devices, deselect Screen Sharing and re-enable the feature.
Disable Remote Management
macOS has a Remote Management feature that lets you manage your Mac from other devices using the Apple Remote Desktop app. You cannot simultaneously enable both “Screen Sharing” and “Remote Management” on macOS. That’s because the Remote Management tool takes control of the Screen Sharing service.
If you don’t use the Apple Remote Desktop app, disable remote management so you can share your MacBook’s screen.
Go to System Preferences > Sharing and deselect Remote Management.
Afterward, check Screen Sharing and check if you can now access your Mac’s screen on other devices.
Switch to an Administrator Account
You need administrative access to use the macOS Screen Sharing service. If you signed in as a Guest user, switch to an administrator account. Click the account name on the Menu Bar (next to the battery icon), select the Administrator account, and enter the account password (or use Touch ID) to sign in.
If you don’t find your account name on the menu bar, go to System Preferences > Dock & Menu Bar > Fast User Switching and check Show in Menu Bar.
Connect Your Devices to the Same Network
To share your MacBook’s screen with another computer, you must connect both devices to the same network. Check your Mac’s connection setting to ensure you’re properly connected to the network.
Extend Display Sleep Timeout
A screen-sharing session may come to an abrupt end if either of the devices goes to sleep. Keep your Mac and the other device awake and ensure they don’t go into sleep mode. You can adjust your Mac’s power settings, so it doesn’t go to sleep during screen sharing.
1. Click the battery icon on the menu bar and select Battery Preferences.
Or, go to System Preferences > Battery to access the Battery Preferences page on your MacBook.
2. By default, macOS turns off your Mac’s display after 2 minutes of inactivity. Move the Turn display off after slider to the right to increase the display timeout duration—maybe 30 minutes or more.
3. Go to the Power Adapter tab and adjust the display timeout to a lengthier period.
If you use a Mac desktop (iMac or Mac Pro), head to System Preferences > Energy Saver to access the Battery Preferences menu.
Note: Remember always to close your MacBook’s lid or put it to sleep when it’s not in use. Constantly leaving the display on for too long will shorten its battery life and possibly damage your Mac.
Enable Screen Recording Access
The first time an app attempts to record or share your Mac’s screen, you’d get a prompt to grant the app screen recording permission. If you deny the permission (perhaps accidentally), screen sharing won’t work with the app on your Mac.
1. Open System Preferences, select Security & Privacy, head to the Privacy tab, and select Screen Recording on the sidebar.
2. Click the lock icon at the bottom-left corner, enter your Mac’s password (or use Touch ID), and ensure the affected app is selected.
If you can’t find the app in the box, you probably denied the app access to record your screen.
3. Click the plus icon to add the app to the list.
4. In the Finder window, go to the Applications folder, select the app to grant screen recording access, and select Open. Afterward, launch the app and try sharing your screen again.
Force Quit and Restart the App
Many times, force-closing an app can fix issues causing the app’s features to freeze or malfunction. If you can’t use screen-sharing within an app, force quit the app and try again.
1. Press Command + Option + Escape to open the “Force Quit Applications” window. Or, select the Apple logo on the menu bar and select Force Quit.
2. Select the problematic app and click the Force Quit button at the bottom corner.
3. Select Force Quit on the prompt.
4. Relaunch the app and check if you can now share your Mac’s screen without issues.
Disable or Change Your Firewall’s Settings
The built-in macOS firewall offers sufficient protection against unwanted intrusion. You don’t need third-party firewall software. Besides slowing down your Mac, many third-party firewalls can block screen-sharing and file-sharing activities. If you have a firewall installed on your Mac, disable the app or ensure it has permission to share your Mac’s screen.
You should also check the configuration of the built-in macOS firewall and ensure the affected app has screen sharing access. Force close the app and follow the steps below.
1. Open System Preferences, select Security & Privacy, go to the Firewall tab, click the lock icon at the bottom-left corner and enter your Mac’s password or authenticate using Touch ID.
2. Select Firewall Options.
3. Make sure you deselect “Block all incoming connections.” Afterward, check the Screen Sharing box and set the screen sharing app’s permission to “Allow incoming connections.” If the app is blocked from sharing your Mac’s screen, click the drop-down button and select Allow incoming connections.
4. If you can’t find the affected app in the Firewall Options, click the plus icon below the “Screen Sharing” box to whitelist the screen-sharing app.
5. Select the app in the Applications folder and click Add.
6. Finally, select OK to save the firewall permissions.
Restart Your Mac
You should power-cycle your Mac if none of the recommendations above resolved Mac screen sharing not working. Click the Apple logo on the menu bar and select Restart.
Be sure to close other apps before restarting your Mac so that you don’t lose any unsaved task or document.
Update the App
Screen sharing may fail to work if the app attempting to record your screen is outdated or buggy. Visit the App Store, the app’s settings menu, or the developer’s website to check if there’s an update available for the app. Install the latest version of the app and try sharing your screen again.
Update or Upgrade Your Mac
You also need to ensure your Mac is up-to-date. Connect your Mac to the internet, go to System Preferences > Software Update and click the Update Now (or Upgrade Now) button.
Contact Apple Support
In the rare instance that these troubleshooting tips don’t resolve when your Mac screen sharing isn’t working, visit a nearby Genius Bar or Apple-certified technician.
