@SGaist Thank you inform about me QtSingleApplication class. I will modify code and use QtSingleApplication.

@newbieQTDev said in Use a QDialog box in Win32 Application:

This is the version of my QT.

No this is the Qt version which was used to build QtCreator (which is a Qt app).
You're using Qt 5.6.0

I found a solution. In case anyone has the same problem just add the following to you CMakeLists.txt:

if(WIN32) set(GUI_TYPE WIN32) elseif(APPLE) set(GUI_TYPE MACOSX_BUNDLE) endif()

then add

${GUI_TYPE}

to your target.

My CMakeLists.txt is now

project(Win32App) cmake_minimum_required(VERSION 3.0.2 FATAL_ERROR) if(WIN32) set(GUI_TYPE WIN32) elseif(APPLE) set(GUI_TYPE MACOSX_BUNDLE) endif() set(SRC main.cpp ) set(HDR) set(RES) add_definitions(-DWIN32 -D_WINDOWS -D_UNICODE -DUNICODE) set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} /SUBSYSTEM:WINDOWS,5.01") add_custom_target(${PROJECT_NAME}_HEADERS SOURCES ${HDR}) add_executable(${CMAKE_PROJECT_NAME} ${GUI_TYPE} ${SRC} ${RES})

Hi and welcome to devnet,

Do you have by any change QT_FATAL_WARNINGS defined ?

If not, can you try the same thing with the 5.6 beta ?

@SGaist Oh, I see where to do that. Thanks. I think that last part makes for a solution.

As soon as paths or library names differ, you will have to use scoped declarations. Otherwise it really does not matter. Win32 also links correctly using -lSomeCoolLib, therefor you could just use one LIBS directive.

@Zylann said:

@JKSH there might be a slight difference in my case actually:
I'm not trying to embed a window from another application, but a HWND created by my own.
Does it makes a difference, or the problem is the same?

Same problems. By "external", I meant "not made by Qt Widgets".

@koahnig
it is out of subject on this forum, but I tested with the win32 function Shellexecute and "runas" as second parameter instead of qprocess and it created my service.so I mark this subject solved.thanks.

This function is only for desktop applications. It may not exist for embedded systems.

I would check if the function exist before doing anything else. If you list the exported functions from USER32 and don't see it then this explains the linker error.