Visual Studio 2019/Qt C++ Executable file not working ?

mrjj

Hi
You need a deployment folder to run the .exe alone
a deployment folder is a folder with the needed Qt DLLS

there is a tool you can use
https://doc.qt.io/qt-5/windows-deployment.html
it will copy the needed DLLS for you.

Also explained here in good details
http://www.tripleboot.org/?p=138

learnist

@mrjj I am now in a state that when i click ```
project_name.exe

nothing happens, Here are the steps i took , i opened Developer Command Prompt for VS 2019, typed this ```
C:\Qt\5.14.1\msvc2017_64\bin>set PATH C:\Qt\5.14.1\msvc2017_64\bin

and then this

C:\Qt\5.14.1\msvc2017_64\bin>windeployqt.exe C:\projects\GAF_Updated\GAF\x64\Release\GafUI.exe

Then the errors about QtWidgets.dll, QtGui.dll missing were gone, but i was facing some other errors like libGLESv2.dll is missing, so i copied it from visual studio folder and pasted it, further i got some other errors like MSVCP140_APP.dll and also VCRUNTIME140_APP.dll is missing , so i downloaded it from the internet and pasted that dll file in my project_name.exe folder,

now when i click it , i get no errors , but when i click projectname.exe file, nothing happens,

Why is deploying in QT so tough ?

mrjj

@learnist
Hi

Why is deploying in QT so tough ?
its only tough the first few times :)

windeployqt.exe has option called --compiler-runtime
that tells it to also copy MSVCP140_APP.dll and VCRUNTIME140_APP.

Just to be sure. you go into the folder and click the .exe, correct ?

To test on same machine where Qt is installed, i often rename the c:\Qt folder
so it cant possibly find anything there.
(i check the .exe and then rename back)

learnist

@mrjj Yes, When i click

project_name.exe

the cursor changes to loading icon and then nothing happens, im not really sure where i went wrong. , is there a way to undo all of this and do it correctly.

mrjj

@learnist
Hi
its just a build folder so you can just delete it and rebuild to get your exe back.
Or simply press ctrl+a and
then hold ctrl and click the exe to deselect it,
then press delete button to delete anything else.

Then open command prompt again and
do
C:\Qt\5.14.1\msvc2017_64\bin>windeployqt.exe --compiler-runtime
C:\projects\GAF_Updated\GAF\x64\Release\GafUI.exe

do you use openGL since it wants libGLESv2 ?
Do you use QML also ?

learnist

@mrjj Hello mrjj, i deleted the release and build it again, so i got a fresh start here, Nope, i did not use OpenGL and QML,

i used Visual Studio 2019 when i was workin on this project. so instead of command prompt should i use "Developer command prompt for VS 2019" ??

mrjj

@learnist said in Visual Studio 2019/Qt C++ Executable file not working ?:

i used Visual Studio 2019 when i was workin on this project. so instead of command prompt should i use "Developer command prompt for VS 2019" ??

I~~t this case it should not be important but should not hurt either.~~
I was wrong . its best to do.
if you have multiple Qt installed then
its important from which folder you start the actual windeployqt.exe - from

learnist

@mrjj I have solved this by placing qt.conf file in my application's .exe folder

[Paths]
Prefix=C:\Qt\5.14.1\msvc2017_64
Defining Prefix in your qt.conf file allows it to find the qwindows.dll platform plugin when your app starts.

if i have a .conf file , i know that application will work perfectly fine on my computer , but not on my friend's computer in which there is no QT installed,

so what i have done is i opened 'Developer command Prompt for Visual Studio 2019' and did this C:\Windows\System32>set PATH=C:/Qt/5.14.1/msvc2017_64/bin;%PATH%
and then

windeployqt C:\projects\GAF_Updated\GAF\x64\Release\GafUI.exe

but still my application.exe was not working, so i noticed that all .dll files were of debug, all of them ended with ...d.dll , for example QWidgetsd.dll, so i deleted them and copied the correct .dll files

i copied correct .dll files(which dont end with 'd') from C:\Qt\5.14.1\msvc2017_64 folder , now my application.exe works,but, there are still some dlls , which i can find in C:\Qt\5.14.1\msvc2017_64 folder , but these are like msvcp140_1d.dll, vcruntime140d.dll , i dunno where can i find them , coz these are not QT specific. these are visual studio related.

Pablo J. Rogina

@learnist said in Visual Studio 2019/Qt C++ Executable file not working ?:

so i noticed that all .dll files were of debug, all of them ended with ...d.dll

You may want to check windeployqt documentation, especially regarding --release switch

learnist

@Pablo-J-Rogina Thanks , This worked just perfect.