Qt for HarmonyOS/qtohosextras doc/Screen Display ID Example
Screen Display ID Example
Demonstrates obtaining the native display ID of the screen a window is shown on.
The window shows the current display ID and a refresh button. The value is queried with QtOhosExtras::tryGetScreenDisplayId() for the screen of the window, once after the window is shown and again on every button click, so the window can be moved to another display and re-queried. A null result is shown as <invalid>.
void updateDisplayId(QWidget *window, QLabel *label)
{
auto displayId = QtOhosExtras::tryGetScreenDisplayId(window->windowHandle()->screen());
label->setText(
QStringLiteral("Display ID: %1")
.arg(displayId
? QString::number(*displayId)
: QLatin1String("<invalid>")));
}