每次在linux安装QT总是会出现各种问题，看了很多博客都不够全面，解决问题花了很大的精力，实属没必要。想写篇尽可能全面的博客记录下来。
QT版本：qt-opensource-linux-x64-5.12.10.run
ubantu版本：18.04桌面版
1、下载
下载地址：https://download.qt.io/archive/qt/5.12/
2、运行安装文件
注意：安装要在系统提供的终端上进行，xshell下无法安装成功
给qt-opensource-linux-x64-5.12.10.run执行权限
chmod +x qt-opensource-linux-x64-5.12.10.run
执行完毕后用ls命令查看qt-opensource-linux-x64-5.12.10.run，确认有执行权限
ls -l qt-opensource-linux-x64-5.12.10.run
此时权限如下所示
3、开始安装
为了跳过QT安装时的登陆账号步骤，安装之前先把网络断开，如果有账号可以不断网。
执行如下命令启动安装程序，安装过程不要关闭终端窗口
./qt-opensource-linux-x64-5.12.10.run
一路下一步，直到选择组件时，最好全选，否则根据用途自行选择
想了解各模块功能的同学，参看如下链接：
Qt Charts：https://blog.csdn.net/u011430225/article/details/79012904
Qt Data Visualization：同上
Qt Purchasing ：https://www.cnblogs.com/findumars/p/5574539.html
Virtual Keyboard：同上
安装完成后，就下而已在如下目录中找到QTCreator了（如果不是安装在home根目录，需要进入指定目录）
~/Qt5.12.10/Tools/QtCreator/bin$
4、安装完毕
此时，qt已经安装完毕，尝试启动qtcreator，在ubantu下时无法启动，出现如下问题
找不到xcb库
This application failed to start because it could not find or load the Qt platform plugin "xcb"
in "".
Available platform plugins are: eglfs, linuxfb, minimal, minimalegl, offscreen, vnc, xcb.
Reinstalling the application may fix this problem.
Aborted (core dumped)
解决方法：
解决方法：
1.sudo gedit ~/.bashrc 输入 export QT_DEBUG_PLUGINS=1 和
export LD_LIBRARY_PATH=/home/itcast/qt/Qt5.12.10/5.12.10/gcc_64/lib:$LD_LIBRARY_PATH（注意把路径替换为自己的安装路径）
2.运行qtcreator，在命令行得到运行中过程，如下
QFactoryLoader::QFactoryLoader() checking directory path "/home/itcast/qt/Qt5.12.10/Tools/QtCreator/lib/Qt/plugins/platforms" ...
QFactoryLoader::QFactoryLoader() looking at "/home/itcast/qt/Qt5.12.10/Tools/QtCreator/lib/Qt/plugins/platforms/libqeglfs.so"
Found metadata in lib /home/itcast/qt/Qt5.12.10/Tools/QtCreator/lib/Qt/plugins/platforms/libqeglfs.so, metadata=
{
"IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
"MetaData": {
"Keys": [
"eglfs"
]
},
"archreq": 0,
"className": "QEglFSIntegrationPlugin",
"debug": false,
"version": 331520
}
Got keys from plugin meta data ("eglfs")
QFactoryLoader::QFactoryLoader() looking at "/home/itcast/qt/Qt5.12.10/Tools/QtCreator/lib/Qt/plugins/platforms/libqlinuxfb.so"
Found metadata in lib /home/itcast/qt/Qt5.12.10/Tools/QtCreator/lib/Qt/plugins/platforms/libqlinuxfb.so, metadata=
{
"IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
"MetaData": {
"Keys": [
"linuxfb"
]
},
"archreq": 0,
"className": "QLinuxFbIntegrationPlugin",
"debug": false,
"version": 331520
}
Got keys from plugin meta data ("linuxfb")
QFactoryLoader::QFactoryLoader() looking at "/home/itcast/qt/Qt5.12.10/Tools/QtCreator/lib/Qt/plugins/platforms/libqminimal.so"
Found metadata in lib /home/itcast/qt/Qt5.12.10/Tools/QtCreator/lib/Qt/plugins/platforms/libqminimal.so, metadata=
{
"IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
"MetaData": {
"Keys": [
"minimal"
]
},
"archreq": 0,
"className": "QMinimalIntegrationPlugin",
"debug": false,
"version": 331520
}
Got keys from plugin meta data ("minimal")
QFactoryLoader::QFactoryLoader() looking at "/home/itcast/qt/Qt5.12.10/Tools/QtCreator/lib/Qt/plugins/platforms/libqminimalegl.so"
Found metadata in lib /home/itcast/qt/Qt5.12.10/Tools/QtCreator/lib/Qt/plugins/platforms/libqminimalegl.so, metadata=
{
"IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
"MetaData": {
"Keys": [
"minimalegl"
]
},
"archreq": 0,
"className": "QMinimalEglIntegrationPlugin",
"debug": false,
"version": 331520
}
Got keys from plugin meta data ("minimalegl")
QFactoryLoader::QFactoryLoader() looking at "/home/itcast/qt/Qt5.12.10/Tools/QtCreator/lib/Qt/plugins/platforms/libqoffscreen.so"
Found metadata in lib /home/itcast/qt/Qt5.12.10/Tools/QtCreator/lib/Qt/plugins/platforms/libqoffscreen.so, metadata=
{
"IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
"MetaData": {
"Keys": [
"offscreen"
]
},
"archreq": 0,
"className": "QOffscreenIntegrationPlugin",
"debug": false,
"version": 331520
}
Got keys from plugin meta data ("offscreen")
QFactoryLoader::QFactoryLoader() looking at "/home/itcast/qt/Qt5.12.10/Tools/QtCreator/lib/Qt/plugins/platforms/libqvnc.so"
Found metadata in lib /home/itcast/qt/Qt5.12.10/Tools/QtCreator/lib/Qt/plugins/platforms/libqvnc.so, metadata=
{
"IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
"MetaData": {
"Keys": [
"vnc"
]
},
"archreq": 0,
"className": "QVncIntegrationPlugin",
"debug": false,
"version": 331520
}
Got keys from plugin meta data ("vnc")
QFactoryLoader::QFactoryLoader() looking at "/home/itcast/qt/Qt5.12.10/Tools/QtCreator/lib/Qt/plugins/platforms/libqxcb.so"
Found metadata in lib /home/itcast/qt/Qt5.12.10/Tools/QtCreator/lib/Qt/plugins/platforms/libqxcb.so, metadata=
{
"IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
"MetaData": {
"Keys": [
"xcb"
]
},
"archreq": 0,
"className": "QXcbIntegrationPlugin",
"debug": false,
"version": 331520
}
Got keys from plugin meta data ("xcb")
QFactoryLoader::QFactoryLoader() checking directory path "/home/itcast/qt/Qt5.12.10/Tools/QtCreator/bin/platforms" ...
loaded library "/home/itcast/qt/Qt5.12.10/Tools/QtCreator/lib/Qt/plugins/platforms/libqxcb.so"
loaded library "Xcursor"
Segmentation fault (core dumped)
3.原因在于libqxcb.so，解决方法：
进入platform目录 ： ~/qt/Qt5.12.10/5.12.10/gcc_64/plugins/platforms（注意路径和安装位置有关） 执行如下命令
ldd libqxcb.so
sudo apt install --reinstall libxcb-xinerama0
source ~/.bashrc
到这里QT就已经可以打开了（注意,QT 需要加sudo才能打开）
sudo ./qtcreator