如何通过Python自动触发Qt可勾选菜单项？

Absolutely, there's a clean way to trigger your checkable QAction programmatically—one that mimics a user clicking it, updating both the GUI state and firing the connected alwaysOnTop function. Here's what you need to know:

1. Use the trigger() Method #

The simplest and most direct approach is to call the QAction's built-in trigger() method. This fully simulates a user clicking the menu item: it toggles the checkable state and emits the triggered signal, which will execute your alwaysOnTop function.

Here's how to implement it:

# This will toggle the check state AND run alwaysOnTop()
action.trigger()

2. Force a Specific Check State + Trigger #

If you need to set the action to a specific checked/unchecked state and trigger the function, you can combine setChecked() with trigger(). Remember that setChecked() alone only updates the GUI state without firing the signal—pairing it with trigger() fixes that:

# Set the action to checked, then trigger the function
action.setChecked(True)
action.trigger()

# Or set to unchecked and trigger
action.setChecked(False)
action.trigger()

Why setChecked() Alone Doesn't Work #

As you noticed, setChecked(True) only modifies the action's internal state and updates the checkbox in the menu. It doesn't emit the triggered signal, which is why your alwaysOnTop function wasn't running. The trigger() method is what explicitly fires that signal, linking the state change to your function execution.

内容的提问来源于stack exchange，提问作者user15953688