实验室有一个大屏幕，连接上了之后输入
xrandr我的输出是这样
Screen 0: minimum 8 x 8, current 3840 x 1080, maximum 32767 x 32767
eDP-1-1 connected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 309mm x 174mm
1920x1080 60.00*+ 59.97 59.96 59.93 48.00
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
HDMI-1-1 connected 1920x1080+1920+0 (normal left inverted right x axis y axis) 531mm x 299mm
1920x1080 60.00*+ 59.94
1600x900 60.00
1280x1024 75.02 60.02
1152x864 75.00
1280x720 60.00 59.94
1024x768 75.03 60.00
800x600 75.00 60.32
640x480 75.00 60.00 59.94
720x400 70.08
DP-1-1 disconnected (normal left inverted right x axis y axis)
HDMI-1-2 disconnected (normal left inverted right x axis y axis)
说明我是一个eDP-1-1（电脑显示屏）+HDMI-1-1（大屏幕）
输入
xrandr --output HDMI-1-1 --same-as eDP-1-1两个屏幕就一样啦
也可以右侧拓展 因为我电脑经常动所以就没再设置
右侧拓展是这个
xrandr --output HDMI-1-1 --right-of eDP-1-1 --auto