1、問題描述

第一步，確保手動啟動Qt程序沒有報錯！如果報以下錯誤，參見博客

qt.qpa.xcb: could not connect to display 
qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though it was found.
This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.Available platform plugins are: xcb.

第二步，在Ubuntu系統中設置自啟動腳本，例如在 /etc/rc.local 文件中添加啟動腳本，但是在自啟動時報錯：

*******XOpenDisplay Fail ******* 
qt.qpa.xcb: could not connect to display 
qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in <