如何阻止Qt Designer为QComboBox应用QPalette（Python环境）

1. Prevent Qt Designer from Generating Custom Palette Code #

• Open your .ui file in Qt Designer.
• Select the problematic myComboBox widget.
• In the Property Editor (right-hand panel), locate the palette property.
• Right-click the palette property and choose Reset to Default. This clears all custom palette configurations for the widget.
• Save the .ui file. Subsequent conversions to Python will no longer generate the lengthy palette code.

2. Reset Palette in Python Script #

If you need to retain other custom settings in Qt Designer, add code after UI initialization to revert the combo box's palette to default:

Option A: Reset to System Default Palette #

After calling setupUi(self) in your Python class, insert:

# Restore system default palette for the combo box
self.myComboBox.setPalette(QtGui.QPalette())

Option B: Inherit Parent Palette #

Use unsetPalette() to remove the custom palette and let the widget inherit settings from its parent or application:

# Remove custom palette to use parent's default styling
self.myComboBox.unsetPalette()

Root Cause of the Issue #

The generated palette code sets the Highlight color (for Active/Inactive states) to white (255,255,255), while HighlightedText remains black. This makes highlighted text invisible because the background and text colors are indistinguishable. Resetting the palette restores the system's default highlight scheme (usually a blue background with white text), fixing the double-click highlight visibility.

内容的提问来源于stack exchange，提问作者slalomchip