因为当输入焦点从下拉式方块移至按钮时，选取范围就会自动清除。

This is because the selection is automatically cleared when the input focus moves from the combo box to the button.

youdao

因为当输入焦点从下拉式方块移至按钮时，选取范围就会自动清除。

This is because the selection is automatically cleared when the input focus moves from the combo box to the button.

youdao