下载Qt在线安装包

这里采用镜像地址进行下载，避免网络过慢。
镜像地址：http://mirrors.ustc.edu.cn/qtproject/archive/online_installers/4.5/
选择最新版本下载，如截至目前最新版本为qt-unified-linux-x64-4.5.2-online.run文件

安装必需环境

Debian/Ubuntu (apt-get)

sudo apt-get install build-essential libgl1-mesa-dev

Fedora/RHEL/CentOS (yum)

sudo yum groupinstall "C Development Tools and Libraries"
sudo yum install mesa-libGL-devel

运行安装程序

首先需要增加执行权限，才能运行。

chmod +x qt-unified-linux-x64-4.5.2-online.run
./qt-unified-linux-x64-4.5.2-online.run

为了使用国内镜像源安装可以使用以下方法：

（推荐）新版本的安装器（4.0.1-1 后）支持 --mirror 命令行参数。在命令行中执行安装器，添加 --mirror https://mirrors.ustc.edu.cn/qtproject 参数。

例如 Windows 下执行当前目录的安装器的命令为

.\qt-unified-windows-x86-online.exe --mirror https://mirrors.ustc.edu.cn/qtproject

Linux为：

./qt-unified-linux-x64-4.5.2-online.run --mirror https://mirrors.ustc.edu.cn/qtproject

或在启动安装器后在设置中禁用默认源，添加新源

 http://mirrors.ustc.edu.cn/qtproject/online/qtsdkrepository/linux_x64/root/qt/ （其他版本注意更改地址）。

安装过程中可能遇到的错误：

在执行run文件时

$ ./qt-unified-linux-x64-4.5.2-online.run 
./qt-unified-linux-x64-4.5.2-online.run: error while loading shared libraries: libxcb-xinerama.so.0: cannot open shared object file: No such file or directory

安装libxcb-xinerama0解决问题

sudo apt install libxcb-xinerama0

之后就是熟悉的安装界面了
在这里插入图片描述
下载所需的Qt版本即可，这里我选择的是最新的Qt 6.5

运行demo可能遇到的问题

在ubuntu-22.04.2 Qt 6.5中可能会有如下警告：

Could NOT find XKB (missing: XKB_LIBRARY XKB_INCLUDE_DIR) (Required is at least version “0.5.0”)

安装

sudo apt install libxkbcommon-dev

Could NOT find WrapVulkanHeaders (missing: Vulkan_INCLUDE_DIR)

Qt6Gui could not be found because dependency WrapOpenGL could not be found

当安装完成之后，运行第一个helloworld程序，无法正常运行。

会遇到如下错误：

CMake Warning at /usr/local/share/cmake-3.26/Modules/CMakeFindDependencyMacro.cmake:76 (find_package):
  Found package configuration file:                 
    /home/Leo/Qt/6.5.0/gcc_64/lib/cmake/Qt6Gui/Qt6GuiConfig.cmake                                             
  but it set Qt6Gui_FOUND to FALSE so package "Qt6Gui" is considered to be NOT FOUND.  Reason given by package:                                                                   
  Qt6Gui could not be found because dependency WrapOpenGL could not be found.                                 
  Configuring with --debug-find-pkg=WrapOpenGL might reveal details why the package was not found.                                                                                 
  Configuring with -DQT_DEBUG_FIND_PACKAGE=ON will print the values of some of the path variables that find_package uses to try and find the package.                                   

Call Stack (most recent call first):                                                                     /home/Leo/Qt/6.5.0/gcc_64/lib/cmake/Qt6/QtPublicDependencyHelpers.cmake:111 (find_dependency)               
/home/Leo/Qt/6.5.0/gcc_64/lib/cmake/Qt6Widgets/Qt6WidgetsDependencies.cmake:39 (_qt_internal_find_qt_dependencies)                                                                                               /home/Leo/Qt/6.5.0/gcc_64/lib/cmake/Qt6Widgets/Qt6WidgetsConfig.cmake:40 (include)                          
/home/Leo/Qt/6.5.0/gcc_64/lib/cmake/Qt6/Qt6Config.cmake:157 (find_package)                                  
  CMakeLists.txt:15 (find_package)                                                                       
CMake Warning at /home/Leo/Qt/6.5.0/gcc_64/lib/cmake/Qt6/Qt6Config.cmake:157 (find_package):
  Found package configuration file:                 
    /home/Leo/Qt/6.5.0/gcc_64/lib/cmake/Qt6Widgets/Qt6WidgetsConfig.cmake                                   
   
  but it set Qt6Widgets_FOUND to FALSE so package "Qt6Widgets" is considered to be NOT FOUND.  Reason given by package:                                    
  Qt6Widgets could not be found because dependency Qt6Gui could not be found.                                 
                                                                                                              
  Configuring with --debug-find-pkg=Qt6Gui might reveal details why the  package was not found.                                                                                 
  Configuring with -DQT_DEBUG_FIND_PACKAGE=ON will print the values of some                                   
  of the path variables that find_package uses to try and find the package.                           
Call Stack (most recent call first):                                                                     
  CMakeLists.txt:15 (find_package)                                                                            
                                                     
CMake Error at CMakeLists.txt:15 (find_package):
  Found package configuration file:                                                                     
    /home/Leo/Qt/6.5.0/gcc_64/lib/cmake/Qt6/Qt6Config.cmake                                                   

  but it set Qt6_FOUND to FALSE so package "Qt6" is considered to be NOT FOUND.  Reason given by package:                                                                                                                    
  Failed to find required Qt component "Widgets".                                                       
  Expected Config file at                                                                               "/home/Leo/Qt/6.5.0/gcc_64/lib/cmake/Qt6Widgets/Qt6WidgetsConfig.cmake"                                     
  exists                                                                                                      

  Configuring with --debug-find-pkg=Qt6Widgets might reveal details why the package was not found.                                                                                 
  Configuring with -DQT_DEBUG_FIND_PACKAGE=ON will print the values of some of the path variables that find_package uses to try and find the package.

原因是因为没有按照第一步安装环境，缺失libgl1-mesa-dev

使用sudo apt install libgl1-mesa-dev安装之后，即可正常运行。