JavaScript事件监听器使字符在箭头右键按下时向右移动

Question

我有一个简单的 JScript HTML 和 CSS 游戏，其中角色必须跳跃，但也可以在按下右箭头时向右移动。我可以使用跳转功能，但是在尝试复制它以创建右箭头功能时，它不起作用。

所需输出： 修正当前代码，以便在按下右箭头时，角色也可以向右移动以及跳跃。按下右箭头键后，角色将继续向右移动。在 keyup 上，它会停止（我是否必须实际为 keyup 和这种可能性创建另一个动画）或者肯定有更简单的方法？

使用更新后的解决方案，它会向右移动，但随后会跳回位置 left:0 而不是停留在移动的位置。

解释：这是一种可接受的编码方式，还是应该将整个代码放在事件监听器中？ （例如整个游戏循环）添加额外的关键移动功能的最佳实践是什么。调用像这样的 CSS 动画是可以接受的还是不好的做法，如果不是，为什么？

我的 JavaScript

var character = document.getElementById("character");
var enemy = document.getElementById("enemy");
function jump(){
 
    if(character.classlist!="animate"){
    character.classList.add("animate");
    }
    setTimeout(function(){
        character.classList.remove("animate");
    },500);
    
}



function right(){
    if(character.classlist!="right"){
    character.classList.add("right");
    }
    setTimeout(function(){
        character.classList.remove("right");
    },500);
    
}



var checkDead =setInterval(function(){
    var characterTop = parseInt(window.getComputedStyle(character).getPropertyValue("top"));
    var enemyLeft = parseInt(window.getComputedStyle(enemy).getPropertyValue("left"));
    
    console.log(characterTop);
    //commented this out while working on css
    /*
    
    if(
        enemyLeft<30 && enemyLeft>0 && characterTop>=360
    )
    {
        enemy.style.animation="none"; //remove the animation
        enemy.style.display="none";
        alert("Poke.....I got you there!");
        
    }
    
    */
    
},10);



addEventListener("keyup", function(e) {
    if(e.keyCode == 38) jump()
})

addEventListener("keyright", function(e) {
    if(e.keyCode == 40) right()
})

我为 keyright 添加的事件监听器基于 keyup 的事件监听器（有效）。

  addEventListener("keyright", function(e) {
        if(e.keyCode == 40) right()
    })

动画在 CSS 中生成

*{
    padding:0;
    margin:22;
}

#game{
    width:500px;
    height:500px;
    border:4px solid #171918;
}

#character{
    width:30px;
    height:120px;
    background-color:green;
    position:relative;
    top:320px;
    border-radius:20px;
    /*animation: jump 300ms */
    
}

/* new class called animate */
.animate{
    animation: jump 500ms;
}

.right{
    animation: right 500ms;
}

#enemy{
    width:60px;
    height:60px;
    background-color:red;
    border-radius:14px;
    position:relative;
    top:320px;
    left:440px;
    animation: moveenemy 1s infinite linear;
    
}

@keyframes moveenemy{
    0%{left:440px;}
    50%{top:58px;}
    100%{left:0px; top:320x;}
}

@keyframes jump{
    0%{top:380px;}
    30%{top:50px;}
    50%{top:40px;}
    100%{top:380px;}
}

@keyframes right{
    0%{left:0px;}
    100%{left:30px;}
}

/* adding sky*/
#sky{
    width:500px;
    height:340px;
    background-color:skyblue;
    position:absolute;
    top:118px;
}

/* adding ground */
#ground{
    width:500px;
    height:170px;
    background-color:bisque;
    position:absolute;
    top:450px;
}

HTML

<!DOCTYPE html>

<html lang="en">

<head>
    <meta charset="UTF-8">
    <title>Document</title>
    <link rel="stylesheet" href="style.css">
    
</head>
<body>
  <h1>B</h1>
  <p>Fight</p>

   
   
   <div id="game">
        <div id="sky"></div>
       <div id="ground"></div>
        <div id="enemy"></div>
       <div id="character"></div>
   </div>
   
<script src="script.js"></script>
</body>

</html>

Answer 1

现在按right arrow时角色会向右移动，按up arrow时角色会跳跃

keyup 是在您松开按键时触发的...而不是在您按下右箭头时触发！

var character = document.getElementById("character");
var enemy = document.getElementById("enemy");

function jump() {

  if (character.classlist != "animate") {
    character.classList.add("animate");
  }
  setTimeout(function() {
    character.classList.remove("animate");
  }, 500);

}



function right() {

  var leftVal =  parseInt(window.getComputedStyle(character).getPropertyValue("left"))
  character.style.left = (leftVal + 30) + "px";

}

function left() {

  var leftVal =  parseInt(window.getComputedStyle(character).getPropertyValue("left"))
  character.style.left = (leftVal - 30) + "px";

}


var checkDead = setInterval(function() {
  var characterTop = parseInt(window.getComputedStyle(character).getPropertyValue("top"));
  var enemyLeft = parseInt(window.getComputedStyle(enemy).getPropertyValue("left"));

  //console.log(characterTop);
  //commented this out while working on css
  /*
    
  if(
      enemyLeft<30 && enemyLeft>0 && characterTop>=360
  )
  {
      enemy.style.animation="none"; //remove the animation
      enemy.style.display="none";
      alert("Poke.....I got you there!");
      
  }
    
  */

}, 10);

addEventListener("keyup", function(e) {
  if (e.keyCode === 37) {
    left()
  }
})

addEventListener("keyup", function(e) {
  if (e.keyCode === 38) {
    jump()
  }
})

addEventListener("keyup", function(e) {
  if (e.keyCode === 39) {
    right()
  }
})

* {
  padding: 0;
  margin: 22;
}

#game {
  width: 500px;
  height: 500px;
  border: 4px solid #171918;
}

#character {
  width: 30px;
  height: 120px;
  background-color: green;
  position: relative;
  top: 320px;
  border-radius: 20px;
  left:0px;
  /*animation: jump 300ms */
}


/* new class called animate */

.animate {
  animation: jump 500ms;
}

.right {
  animation: right 500ms;
}

#enemy {
  width: 60px;
  height: 60px;
  background-color: red;
  border-radius: 14px;
  position: relative;
  top: 320px;
  left: 440px;
  animation: moveenemy 1s infinite linear;
}

@keyframes moveenemy {
  0% {
    left: 440px;
  }
  50% {
    top: 58px;
  }
  100% {
    left: 0px;
    top: 320x;
  }
}

@keyframes jump {
  0% {
    top: 380px;
  }
  30% {
    top: 50px;
  }
  50% {
    top: 40px;
  }
  100% {
    top: 380px;
  }
}

@keyframes right {
  0% {
    left: 0px;
  }
  100% {
    left: 30px;
  }
}


/* adding sky*/

#sky {
  width: 500px;
  height: 340px;
  background-color: skyblue;
  position: absolute;
  top: 118px;
}


/* adding ground */

#ground {
  width: 500px;
  height: 170px;
  background-color: bisque;
  position: absolute;
  top: 450px;
}

<!DOCTYPE html>

<html lang="en">

<head>
  <meta charset="UTF-8">
  <title>Document</title>
  <link rel="stylesheet" href="style.css">

</head>

<body>
  <h1>B</h1>
  <p>Fight</p>



  <div id="game">
    <div id="sky"></div>
    <div id="ground"></div>
    <div id="enemy"></div>
    <div id="character"></div>
  </div>

  <script src="script.js"></script>
</body>

</html>