Question

我想通过按住右箭头键来增加整数。我做的功能有效，但返回得太快。

document.onkeydown = function (e) {
                e = e || window.event;
                if (e.keyCode == '39') {

                        var steps = localStorage.getItem("steps");
                        if (+steps < 9) {
                            if (+steps === +steps) {
                                localStorage.setItem("steps", +steps + +1)
                            }
                        } else {
                            localStorage.setItem("steps", +steps - +10);
                        }
                        var sss = localStorage.getItem("steps");

                        unicorn.className = "unicorn_" + sss + "";

                        return false;
                }
            }

上面的代码是我现在所处的位置。我使用localStorage检查存储的整数，如果匹配则递增。一旦整数达到9，它就会减去0。

任何人都可以看到我做错了什么，或者做不对？

Answer 1

您还可以使用闭包手动跟踪时间：

document.onkeydown = (function () {

    var T0 = Date.now();

    return function (event) {
        if (Date.now() - T0 > 500) {
            console.log("doing my thing over here", Math.random());
            T0 = Date.now();
        }
    }
})();

Answer 2

如果您不希望它执行too fast，请考虑将其放入setTimeout

var notTooFast = false;
var timeout   = 1000; // change it whatever you want to be

document.onkeydown = function (e) {
  e = e || window.event;
  if (e.keyCode == '39') {

    if (!notTooFast)
    {
      var steps = localStorage.getItem("steps");
      if (+steps < 9) {
          if (+steps === +steps) {
              localStorage.setItem("steps", +steps + +1)
          }
      } else {
          localStorage.setItem("steps", +steps - +10);
      }
      var sss = localStorage.getItem("steps");

      unicorn.className = "unicorn_" + sss + "";

      notTooFast = true;
      setTimeout(function () {
          notTooFast = false;
      }, timeout);

      return false;
    }
  }
}

有没有办法制作＆＃34; onkeydown＆＃34;回来慢点

2 个答案: