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Qt for HarmonyOS/qtohosextras doc/Screen Display ID Example

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Revision as of 02:48, 17 September 2026 by Shawn Luo (talk | contribs) (Publish example source listings and restore Files lists (QTFOROH-2307))

< Qt for HarmonyOS / qtohosextras doc

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>")));
 }

Files: