Question

我想用用户输入（按钮）运行此代码，但我不知道如何操作。另外，我从互联网上获得了一些这样的代码，所以我仍然不太明白为什么颜色变量数组中有6种颜色，而不是只有3种颜色（红色，黄色，绿色）。我也不太了解if语句，所以如果你能解释为什么我真的需要var时间，那就太好了。谢谢！

＆＃13;

var time = 5;

function lights() {
  var red = document.getElementById('redLight')
  var yellow = document.getElementById('yellowLight')
  var green = document.getElementById('greenLight')
  var Colours = ["#FF0000", "#FFB300", "#05FF0D", "#7A0000", "#7A5C00", "#008000"];
  if (time == 5) {
    red.style.background = Colours[0]; 
    yellow.style.background = Colours[4];
    green.style.background = Colours[5];
    time = 1;
  } else if (time == 2 || time == 4) {
    red.style.background = Colours[3];
    yellow.style.background = Colours[1];
    green.style.background = Colours[5];
  } else if (time == 3) {
    red.style.background = Colours[3];
    yellow.style.background = Colours[4]
    green.style.background = Colours[2];

  }
  time += 1
};
setInterval(function() {
  lights();
}, 2000);

＆＃13;

  <h1> Traffic Light </h1>
        <div id="redLight"></div>
        <div id="yellowLight"></div>
        <div id="greenLight"></div>
        <div id="box"></div>

＆＃13;

Answer 1

您可以添加<button onclick="test()"></button>按钮然后你把间隔放在我称之为测试的函数中。喜欢： function test(){setInterval(lights(),2000)

Answer 2

使用<button onclick=></button>。或者，您也可以使用<div> <div onclick=></div>进行onclick：private GradientDrawable imageButtonGradient() { GradientDrawable buttonShape = new GradientDrawable(); buttonShape.setCornerRadius(20); buttonShape.setColor(Color.WHITE); return buttonShape; }。

Answer 3

var time = 5;

function lights() {
  var red = document.getElementById('redLight')
  var yellow = document.getElementById('yellowLight')
  var green = document.getElementById('greenLight')
  var Colours = ["#FF0000", "#FFB300", "#05FF0D", "#7A0000", "#7A5C00", "#008000"];
  if (time == 5) {
    red.style.background = Colours[0]; 
    yellow.style.background = Colours[4];
    green.style.background = Colours[5];
    time = 1;
  } else if (time == 2 || time == 4) {
    red.style.background = Colours[3];
    yellow.style.background = Colours[1];
    green.style.background = Colours[5];
  } else if (time == 3) {
    red.style.background = Colours[3];
    yellow.style.background = Colours[4]
    green.style.background = Colours[2];

  }
  time += 1
};
setInterval(function() {
  lights();
}, 2000);

  <h1> Traffic Light </h1>
        <div id="redL"></div>
        <div id="yellowL"></div>
        <div id="greenL"></div>
        <div id="box"></div>

如何为此JavaScript和HTML代码添加一个按钮，以便当我按下按钮时，我的红绿灯序列会运行一次？

3 个答案: