So, I wanted to implemented a placeholder text for a list (QListView) which would be displayed if the list has no items.

Currently I'm doing it using QStackedLayout but it requires quite a bit of boilerplate. You need to create a wrapper QWidget that will hold QStackedLayout, and also another wrapper QWidget for placeholder text so it can be centered:

auto stackedLayoutWrapper = new QWidget(parent); auto stackedLayout = new QStackedLayout(stackedLayoutWrapper); stackedLayout->addWidget(listView); auto placeholderWrapper = new QWidget(); auto placeholderLayout = new QVBoxLayout(placeholderWrapper); auto placeholder = new QLabel("No items"); placeholderLayout->addItem(placeholder, 0, Qt::AlignCenter); stackedLayout->addWidget(placeholderWrapper);

And then I discovered another neat way to do it, using QListView::viewport():

auto placeholderLayout = new QVBoxLayout(listView->viewport()); auto placeholder = new QLabel("No items"); placeholderLayout->addWidget(placeholder, 0, Qt::AlignCenter);

This works right now, but question is, how safe is it set a layout on the viewport() like this?

@michaelcarlos said in Best Way to Optimize a Qt Quick Application for Smooth Performance?:

Are there any profiling tools that are Qt-specific and will allow me to identify bottlenecks?

The QML profiler built into Creator (Analyze -> QML Profiler) has worked for me in the past.

@Tim-Jenssen
Thanks for your reply. I got limited resources tracking this issue. Appreciate for your help. If u need more info debugging this from my side, feel free to ask.

@jagadish Thank you

Introducing the QML for Beginners Learning Path & Challenges!

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Introduction to QML Introduction to Qt Quick Introduction to Qt Quick Controls Positioners and Layouts Model View Delegate with QML QML Best Practice QML Fluid Elements and Animations QML Debugging Basics with Qt Creator

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When you want to include some headers of a library you also must pass the include path to the compiler.
If you use cmake, use target_include_directories() and add the desired include paths there. Later when you use this library (aka you link them with target_link_libraries()), cmake will automatically add the paths specified.

刚刚接触QT，菜单直接打开链接到某个文件"

They still send you this trash after you unsubscribe. Had to fully block qt in my mail client.

They are very stupid for not using a mail provider for that spam. Now their URL is being flagged by all of us.