LNK2019 problems when trying to get custom window frame in Qt - c++

Question

I want a custom window frame for an app I've made in Qt 5.4 with QML.Before implementing it on my main project, I tried the following on a default application:
int main(int argc, char *argv[])
{
QApplication app(argc, argv);
//QQmlApplicationEngine engine;
//engine.load(QUrl(QStringLiteral("qrc:/main.qml")));
QDeclarativeView view;
viewsetWindowFlags(Qt::FramelessWindowHint
| Qt::WindowSystemMenuHint
| Qt::WindowMinimizeButtonHint
| Qt::Window);
view.setAttribute(Qt::WA_TranslucentBackground);
view.setMaximumHeight(640);
view.setMaximumWidth(350);
view.viewport()->setAutoFillBackground(false);
view.show();
return app.exec();
}
Here is the .pro file:
TEMPLATE = app
QT += qml quick widgets
QT += core gui widgets quick
QT += network
SOURCES += main.cpp
RESOURCES += qml.qrc
# Additional import path used to resolve QML modules in Qt Creator's code model
QML_IMPORT_PATH =
# Default rules for deployment.
include(deployment.pri)
The errors:
main.obj:-1: error: LNK2019: unresolved external symbol "__declspec(dllimport) public: __cdecl QDeclarativeDebuggingEnabler::QDeclarativeDebuggingEnabler(void)" (__imp_??0QDeclarativeDebuggingEnabler##QEAA#XZ) referenced in function "void __cdecl `dynamic initializer for 'qmlEnableDebuggingHelper''(void)" (??__EqmlEnableDebuggingHelper##YAXXZ)
main.obj:-1: error: LNK2019: unresolved external symbol "__declspec(dllimport) public: __cdecl QDeclarativeView::QDeclarativeView(class QWidget *)" (__imp_??0QDeclarativeView##QEAA#PEAVQWidget###Z) referenced in function main
main.obj:-1: error: LNK2019: unresolved external symbol "__declspec(dllimport) public: virtual __cdecl QDeclarativeView::~QDeclarativeView(void)" (__imp_??1QDeclarativeView##UEAA#XZ) referenced in function main
I know this is related to my .pro file but not too good in understanding LNk errors, I've tried different things but no progress, till now. How to fix this?

Answer 1

Add to the pro file:
QT += declarative
From the doc:
For the purposes of porting older applications, the QtDeclarative
module is still available in Qt 5 but has been renamed to Qt Quick 1.
Applications that required Qt Quick 1 specific API (e.g.
QDeclarativeView or QDeclarativeItem and the Graphics View
integration) can use this module. Note that new applications should
use the new Qt QML and Qt Quick modules instead.
To use the Qt Quick 1 module, add "declarative" to your qmake .pro
file:
Required header files can be included as follows:
#include <QtDeclarative/QDeclarativeView>
#include <QtDeclarative/QDeclarativeItem>
Also:
All classes that were previously in the QtDeclarative module have been
moved into the Qt QML and Qt Quick modules, and their class names have
been changed to reflect their new module locations. The class name
changes are as follows:
... QDeclarativeView -> QQuickView
But:
(The QtDeclarative module is still available to developers as the Qt
Quick 1 module, as discussed below. However, it should not be used for
new applications.)