flutter 防止重复点击

 DateTime ? lastPopTime;
 if (lastPopTime == null ||
                  DateTime.now().difference(lastPopTime) >
                      Duration(seconds: 2)) {
                print(lastPopTime);
                lastPopTime = DateTime.now();
            do somesing
              } else {
                // lastPopTime = DateTime
                //     .now(); //如果不注释这行,则强制用户一定要间隔2s后才能成功点击. 而不是以上一次点击成功的时间开始计算.
                print("请勿重复点击！");
              }