/*********************************************************************************
* error: QXcbConnection: Could not connect to display
* 说明：
* 调试Qt5支持XCB平台模式的时候遇到的错误。
*
* 2017-11-28 深圳 南山平山村 曾剑锋
********************************************************************************/
一、参考文档：
1. Qt5： QXcbConnection: Could not connect to display Aborted (core dumped)
http://bbs.csdn.net/topics/391894181
二、Qt支持X11 XCB
/home/zengjf/zengjf/zengjfos/buildroot-2017.02.3/.config - Buildroot 2017.02.3 C
o> Target packages > Graphic libraries and applications (graphic/text) > Qt5 ──
┌────────────────────────────────── Qt5 ──────────────────────────────────┐
│ Arrow keys navigate the menu. <Enter> selects submenus ---> (or empty │
│ submenus ----). Highlighted letters are hotkeys. Pressing <Y> │
│ selectes a feature, while <N> will exclude a feature. Press │
│ <Esc><Esc> to exit, <?> for Help, </> for Search. Legend: [*] feature │
│ ┌────^(-)─────────────────────────────────────────────────────────────┐ │
│ │ -*- gui module │ │
│ │ -*- widgets module │ │
│ │ *** OpenGL support needs an OpenGL-capable backend *** │ │
│ │ [*] linuxfb support │ │
│ │ *** directfb backend available if directfb is enabled *│ │
│ │ [*] X.org XCB support │ │
│ │ *** eglfs backend available if OpenGL and EGL are enabl│ │
│ │ (xcb) Default graphical platform │ │
│ │ [ ] fontconfig support │ │
│ │ [ ] GIF support │ │
│ └────┴(+)─────────────────────────────────────────────────────────────┘ │
├─────────────────────────────────────────────────────────────────────────┤
│ <Select> < Exit > < Help > < Save > < Load > │
└─────────────────────────────────────────────────────────────────────────┘
三、错误解决方法
1. Error 1
1. cmd: ./Helloworld -platform xcb
2. error: QXcbConnection: Could not connect to display
3. resolution: export DISPLAY=:0.0
2. Error 2
1. cmd: ./Helloworld -platform xcb
2. error: QXcbConnection: Could not connect to display :0.0
3. resolution: 检查X11 Server正常运行
