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Preserving Aspect Ratio in Qt's QLabel with QPixmap
In Qt, displaying an image in a QLabel often poses the challenge of resizing while preserving its aspect ratio. This is especially important when dealing with dynamic changes in the source image's dimensions.
Keeping Aspect Ratio with Size Policy
To address this, adjust the label's QSizePolicy to allow for expansion or minimum expansion. For example:
<code class="cpp">QLabel label; label.setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);</code>
Scaling the QPixmap
To scale the QPixmap within the QLabel while maintaining the aspect ratio, add the following code:
<code class="cpp">QPixmap pixmap; // Assumed loaded from a source int labelWidth = label.width(); int labelHeight = label.height(); label.setPixmap(pixmap.scaled(labelWidth, labelHeight, Qt::KeepAspectRatio));</code>
Insert this code in two locations:
This setup ensures that the QLabel resizes to accommodate the QPixmap while preserving its aspect ratio, following the available space.
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