更新至 18.04 版后，我的外接显示器无法再被检测到。我尝试遵循以下建议：Ubuntu 18.04 上未检测到外接显示器（添加模式、安装 lightdm 等）但无济于事。输出xrandr如下：
Screen 0: minimum 320 x 200, current 1920 x 1080, maximum 8192 x 8192
eDP-1 connected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 294mm x 165mm
1920x1080 60.02*+ 60.01 59.97 59.96 59.93 48.01
1680x1050 59.95 59.88
1600x1024 60.17
1400x1050 59.98
1600x900 59.99 59.94 59.95 59.82
1280x1024 60.02
1440x900 59.89
1400x900 59.96 59.88
1280x960 60.00
1440x810 60.00 59.97
1368x768 59.88 59.85
1360x768 59.80 59.96
1280x800 59.99 59.97 59.81 59.91
1152x864 60.00
1280x720 60.00 59.99 59.86 59.74
1024x768 60.04 60.00
960x720 60.00
928x696 60.05
896x672 60.01
1024x576 59.95 59.96 59.90 59.82
960x600 59.93 60.00
960x540 59.96 59.99 59.63 59.82
800x600 60.00 60.32 56.25
840x525 60.01 59.88
864x486 59.92 59.57
800x512 60.17
700x525 59.98
800x450 59.95 59.82
640x512 60.02
720x450 59.89
700x450 59.96 59.88
640x480 60.00 59.94
720x405 59.51 58.99
684x384 59.88 59.85
680x384 59.80 59.96
640x400 59.88 59.98
576x432 60.06
640x360 59.86 59.83 59.84 59.32
512x384 60.00
512x288 60.00 59.92
480x270 59.63 59.82
400x300 60.32 56.34
432x243 59.92 59.57
320x240 60.05
360x202 59.51 59.13
320x180 59.84 59.32
DP-1 disconnected (normal left inverted right x axis y axis)
HDMI-1 disconnected (normal left inverted right x axis y axis)
显卡（运行sudo lshw -C video）的详细信息如下：
*-display
description: VGA compatible controller
product: Intel Corporation
vendor: Intel Corporation
physical id: 2
bus info: pci@0000:00:02.0
version: 02
width: 64 bits
clock: 33MHz
capabilities: pciexpress msi pm vga_controller bus_master cap_list rom
configuration: driver=i915 latency=0
resources: irq:131 memory:f0000000-f0ffffff memory:e0000000-efffffff ioport:e000(size=64) memory:c0000-dffff
有什么想法可以解决这个问题吗？我尝试使用相同的显示器和相同的电缆将同事笔记本电脑上的 Ubuntu 先前版本连接到一起，没有任何问题。
根据建议进行编辑：
使用实时图像部分解决了我的问题：我加载实时图像，重新启动计算机并提取它，现在它又出现了。奇怪的是，现在我登录时两个屏幕都被克隆了，但一旦我登录，显示器屏幕就会变黑。但是，如果我拔下并再次插入 HDMI 电缆，我就会得到我想要的配置（作为连接显示器，在显示器屏幕上有图标和栏）。