一般来讲，编译生成 Qt5 应用程序后，直接双击应用程序，会跳出缺少这个 dll 缺少那个 dll 的错误。那么怎么来找齐这些 dll 呢？

一、蛮力大法

顾名思义，就是一个一个dll找。先把exe复制到一个文件夹里，双击运行，根据提示，一个一个从Qt的bin文件夹里找到这些dll文件。

可是这种方法很不优雅啊？

二、设置路径法

这种方法，需要在目标机里再重新安装一次Qt，然后将Qt的bin路径设置到环境变量里面。倒也很省事，只是如果目标机不方便安装Qt，也就不好办了。

三、使用 windeployqt 工具

打开Qt程序目录里面的命令行，敲入 windeployqt –help 命令，就会蹦出他的详细用法

C:\Qt\Qt5.3.2\5.3\mingw482_32>windeployqt --help
Usage: windeployqt [options] [file]
Qt Deploy Tool 5.3.2

The simplest way to use windeployqt is to add the bin directory of your Qt
installation (e.g. <QT_DIR\bin>) to the PATH variable and then run:
  windeployqt <path-to-app-binary>
If ICU, ANGLE, etc. are not in the bin directory, they need to be in the PATH
variable. If your application uses Qt Quick, run:
  windeployqt --qmldir <path-to-app-qml-files> <path-to-app-binary>

Options:
  -?, -h, --help             Displays this help.
  -v, --version              Displays version information.
  --dir <directory>          Use directory instead of binary directory.
  --libdir <path>            Copy libraries to path.
  --debug                    Assume debug binaries.
  --release                  Assume release binaries.
  --force                    Force updating files.
  --dry-run                  Simulation mode. Behave normally, but do not
                             copy/update any files.
  --no-plugins               Skip plugin deployment.
  --no-libraries             Skip library deployment.
  --qmldir <directory>       Scan for QML-imports starting from directory.
  --no-quick-import          Skip deployment of Qt Quick imports.
  --no-translations          Skip deployment of translations.
  --no-system-d3d-compiler   Skip deployment of the system D3D compiler.
  --compiler-runtime         Deploy compiler runtime (Desktop only).
  --no-compiler-runtime      Do not deploy compiler runtime (Desktop only).
  --webkit2                  Deployment of WebKit2 (web process).
  --no-webkit2               Skip deployment of WebKit2.
  --json                     Print to stdout in JSON format.
  --list <option>            Print only the names of the files copied.
                             Available options:
                              source:   absolute path of the source files
                              target:   absolute path of the target files
                              relative: paths of the target files, relative
                                        to the target directory
                              mapping:  outputs the source and the relative
                                        target, suitable for use within an
                                        Appx mapping file
  --verbose <level>          Verbose level.

Qt libraries can be added by passing their name (-xml) or removed by passing
the name prepended by --no- (--no-xml). Available libraries:
bluetooth clucene concurrent core declarative designer designercomponents
enginio gui qthelp multimedia multimediawidgets multimediaquick network nfc
opengl positioning printsupport qml quick quickcompilerruntime quickparticles
quickwidgets script scripttools sensors serialport sql svg test webkit
webkitwidgets websockets widgets winextras xml xmlpatterns

Arguments:
  [file]                     Binary or directory containing the binary.

比如  LT 编译出来的应用程序路径为  C:\Users\liangtao\Documents\Qt Projects\build-test_hmi-Desktop_Qt_5_3_MinGW_32bit-Release\release\test_hmi.exe，那么输入命令

C:\Qt\Qt5.3.2\5.3\mingw482_32>windeployqt "C:\Users\liangtao\Documents\Qt Projec
ts\build-test_hmi-Desktop_Qt_5_3_MinGW_32bit-Release\release\test_hmi.exe"
C:\Users\liangtao\Documents\Qt Projects\build-test_hmi-Desktop_Qt_5_3_MinGW_32bi
t-Release\release\test_hmi.exe 32 bit, release executable
Skipping plugin qtaccessiblequick.dll due to disabled dependencies.
Adding Qt5Svg for qsvgicon.dll
Direct dependencies: Qt5Core Qt5Widgets
All dependencies   : Qt5Core Qt5Gui Qt5Widgets
To be deployed     : Qt5Core Qt5Gui Qt5Svg Qt5Widgets
Updating icuin52.dll.
Updating icuuc52.dll.
Updating icudt52.dll.
Updating Qt5Core.dll.
Updating Qt5Gui.dll.
Updating Qt5Svg.dll.
Updating Qt5Widgets.dll.
Updating libgcc_s_dw2-1.dll.
Updating libstdc++-6.dll.
Updating libwinpthread-1.dll.
Creating directory accessible.
Updating qtaccessiblewidgets.dll.
Creating directory iconengines.
Updating qsvgicon.dll.
Creating directory imageformats.
Updating qdds.dll.
Updating qgif.dll.
Updating qicns.dll.
Updating qico.dll.
Updating qjp2.dll.
Updating qjpeg.dll.
Updating qmng.dll.
Updating qsvg.dll.
Updating qtga.dll.
Updating qtiff.dll.
Updating qwbmp.dll.
Updating qwebp.dll.
Creating directory platforms.
Updating qwindows.dll.
Creating qt_cs.qm...
Creating qt_de.qm...
Creating qt_fi.qm...
Creating qt_hu.qm...
Creating qt_it.qm...
Creating qt_ja.qm...
Creating qt_ru.qm...
Creating qt_sk.qm...
Creating qt_uk.qm...

可以看到它自动把一大堆dll搬运到这个目录里面，运行看看，可以运行了！

源码下载

test_hmi.zip

四、扩展阅读

• Qt for Windows – Deployment
  http://doc.qt.io/qt-5/windows-deployment.html#application-dependencies
• This Linux Deployment Tool
  https://github.com/probonopd/linuxdeployqt