Qt5 静态构建产生无法加载平台插件“windows”

Question

I am writing a Qt application on Windows using Visual Studio 2012 . Using the Qt Add-in and a custom built static distribution of Qt 5.0.2 . I am running into the dreaded "Failed to load platform plugin windows" error whenever I run the application. I have added the following to the linker input:

imm32.lib
winmm.lib
Ws2_32.lib
qtmaind.lib
Qt5Cored.lib
Qt5Guid.lib
Qt5Widgetsd.lib

At first I thought that maybe I should add "qwindowsd.lib" to that list as well however that did not fix the problem. What do I need to do in order to make my application run?

Answer 1

For dynamic build only: Make sure you move the qwindows.dll to the following directory:

yourapp.exe
Qt5Core.dll
...
platforms/qwindows.dll
...

Note that the plugins directory is missing! You put all the needed folders from QT_BASE/.../plugins/* directly together with your binaries. BTW: I did not need libEGL.dll, but my application almost has no GUI.

My source: http://qt-project.org/forums/viewthread/27056/#122588

Answer 2

I solved it. Thanks to this I was able to get everything to work. I added the following libraries:

opengl32.lib
Qt5PlatformSupport.lib
qwindows.lib

I also added the following to my code:

#include <QtPlugin>
Q_IMPORT_PLUGIN (QWindowsIntegrationPlugin);

Answer 3

I had the same error with MinGW version of Qt (not static): "Failed to load platform plugin windows".

The solution for me was to add the DLLs libEGL.dll and libEGLd.dll .

Answer 4

You could also make an environment variable:

QT_QPA_PLATFORM_PLUGIN_PATH=<QT_BASE>\\plugins\\platforms

which in my case becomes: QT_QPA_PLATFORM_PLUGIN_PATH=f:\\Qt\\5\\5.4\\msvc2013_opengl\\plugins\\platforms

Thus avoiding installing/copying qwindows.dll during development (to save disk-space!?).

This solution was also mentioned on GitHub and here .

EDIT: Sorry, this is not effective in a static build. But I'll leave my A here.

Answer 5

Ok I had similar issue.

I found out that QT 5.2+ has windeployq.exe

QT_DIRECTORY\\5.2...\\bin\\windeployq.exe

Use it with the directory of your project (where the .exe of your application is). And voilà ! Automatically linked everything and ready to deploy !

It will get the DLLs, Plugins etc... automatically !

Answer 6

另一种方法是将qtbase/plugins/platforms目录复制到 Debug/Release 目录中，根据需要仅qwindowsd.dll或qwindows.dll 。

Answer 7

解决方案是，如果您使用 anaconda 和 python 使用 qt 设计器制作 gui，则转到 anaconda,pkgs,qt.xxx,library,plugins ，然后将平台文件夹复制到包含您的 program.exe 的构建文件夹中

Answer 8

Starting with QT 5.9+ Qt5PlatformSupport.lib is no longer available and has been split into different libraries. To create a static build under windows one needs to link the following additional libraries:

Qt5FontDatabaseSupport.lib
Qt5EventDispatcherSupport.lib
Qt5ThemeSupport.lib
Qt5PlatformCompositorSupport.lib
Qt5AccessibilitySupport.lib
Qt5WindowsUiAutomationSupport.lib
qwindows.lib

and load the windows plugin statically :

#include <QtPlugin>
Q_IMPORT_PLUGIN (QWindowsIntegrationPlugin);

Answer 9

I exactly this probelm. The solution is to check the Qt in Debug output. That window tells you all the DLLs it loads. These are the ones you may need in your distribution exe folder.

Answer 10

I had the same error with VS2015 and the version of Qt 5.9.3

I solved the error by replacing the Qt5Cored.dll and Qt5Core.dll(where the exe of my application) with the same DLLs in Qt directory