Flutter 之點擊空白處取消TextField焦點

GestureDetector(
    behavior: HitTestBehavior.translucent,
    onTap: () {
        // 觸摸收起鍵盤
        FocusScope.of(context).requestFocus(FocusNode());
    },
    child: *******
}

注：必定要放到最外層