[SOLVED] { Qt5.0.2/QtQuick2.0/C++ } What is the right way to make a class outside main.cpp to use QtQuick2ApplicationViewer?
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I have described the question in detail in stack overflow:
The problem:
I want to make a C++ application that uses QML for dialog UI.
I am trying to put my UI code outside main.cpp (in a class called "Dialog"), so that I can later separate it to run in a thread.
I build & run: No errors in compilation, no errors in application output.
However, nothing shows up on the screen. But if written in main.cpp, this chunk of code shows the QML dialog correctly:
@QtQuick2ApplicationViewer viewer;
viewer.setMainQmlFile(QStringLiteral("qml/Kiosk/main.qml"));viewer.showExpanded();@
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I wonder why this is happening, could you please advise - what am I doing wrong?
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Looking at the code you posted on stack overflow I notice that you are creating an instance of QtQuick2ApplicationViewer on the stack.
@
void Dialog::show()
{
QtQuick2ApplicationViewer viewer;
viewer.setMainQmlFile(QStringLiteral("qml/Kiosk/main.qml"));viewer.showExpanded();}
@This will go out of scope and be destroyed once your function returns.
Try this:
@
void Dialog::show()
{
QtQuick2ApplicationViewer *viewer = new QtQuick2ApplicationViewer;
viewer->setMainQmlFile(QStringLiteral("qml/Kiosk/main.qml"));viewer->showExpanded();}
@You will need to retain the viewer pointer and explicitly call delete in order to avoid memory leaks.