If you look at the UEditableText class, you can see that the WidgetStyle object is only used when the RebuildWidget function is called, as shown in the previous answer.
This means that updating the WidgetStyle variable does not actually cause any changes to the Slate object.
So I haven’t found a way to update the Style of the UEditableText at runtime as I want without changing the UEditableText class.
In my case, I only needed to change the font information out of the entire style, so my solution was to borrow the way a UTextBlock with a similar structure changes the font and add a custom class that inherits from UEditableText.
Of course, since I am working in a Blueprint environment, these additional class registrations were necessary, but If in a C++ environment, you may get the internal Slate widget with TakeWidget() and do the updates directly.
Here are the additional interfaces I registered
void UMyEditableText::SetFont(FSlateFontInfo InFont)
{
if(!WidgetStyle.Font.IsIdenticalTo(InFont))
{
WidgetStyle.Font = InFont;
if (MyEditableText.IsValid())
{
MyEditableText->SetFont(InFont);
MyEditableText->Invalidate(EInvalidateWidgetReason::LayoutAndVolatility);
}
}
}
Hope this helps.