你没发现那段代码是当发生语言改变时改变语言吗，那个ui->retranslateUi(this); 就是改变语言的函数了。
参见：
void QWidget::changeEvent ( QEvent * event ) [virtual protected]
This event handler can be reimplemented to handle state changes.
The state being changed in this event can be retrieved through the event supplied.
Change events include: QEvent::ToolBarChange, QEvent::ActivationChange, QEvent::EnabledChange, QEvent::FontChange, QEvent::StyleChange, QEvent::PaletteChange, QEvent::WindowTitleChange, QEvent::IconTextChange, QEvent::ModifiedChange, QEvent::MouseTrackingChange, QEvent::ParentChange, QEvent::WindowStateChange, QEvent::LanguageChange, QEvent::LocaleChange, QEvent::LayoutDirectionChange.
