Ubuntu 12.04 dual-screen configuration tutorial

View the LVDS1 information of the current monitor.
Daitr @ aa :~ $ XrandrScreen 0: minimum 320x200, current 2646x1024, maximum 8192x8192LVDS1 connected 1366x768 + 0 + 0 (normal left inverted right x axis y axis) 309x174mm1366x768 60.0 * + www.2cto.com 1360x768 59.8 60.0x1024 768 60.0x800 600 60.3 56.2x640 480 59.9
The other displays VGA1 information.
VGA1 connected 1280x1024 + 1366 + 0 (normal left inverted right x axis y axis) 376mm x 301mm1280x1024 60.0 x + 75.0 1152x864 75.0x1024 768 75.1x60.0 800 600x75.0 60.3 640 480x75.0 60.0 720 www.2cto.com HDMI1 disconnected (normal left inverted right x axis y axis) DP1 disconnected (normal left inverted right x axis y axis) displays the display on the right of the current book:
Daitr @ aa :~ $ Xrandroid -- ouput VGA1 -- auto -- right-of LVDS1 turn off the monitor VGA1daitr @ aa :~ $ Xrandroid -- output VGA1 -- off enable the monitor VGA1daitr @ aa :~ $ Xrandroid -- output VGA1 -- auto enable the monitor VGA1 on the right daitr @ aa :~ $ Xrandroid -- output VGA1 -- auto -- right of test