【发布时间】：2020-06-19 21:59:21
【问题描述】：
我编写了一个游戏 java 脚本代码，我需要在 HTML 中显示分数变量点。我试了一下，但它总是打印 0 而不会增加分数。 Score 变量递增 1，但在 HTML 页面上一直显示 0。我应该在哪里更改标签以正确显示它，还是需要更改它的 java script score 函数？
我的 Java 脚本代码：
var notes = [];
var gameStarted = false;
var Score = 0;
// ==== CLASS FOR ARROWS ==== //
// 1. Direction of arrows
// 2. jQuery img that links to direction bottom
// 3. Destroy when it arrow gets to the
// 4. Explode when arrow gets to the bottom
// Class Arrow
function Arrow(direction) {
// CSS spacings for the arrows //
var xPos = null;
switch(direction) {
case "left" : xPos = "350px";
break;
case "up" : xPos = "420px";
break;
case "down" : xPos = "490px";
break;
case "right" : xPos = "560px";
break;
}
this.direction = direction;
this.image = $("<img src='./arrows/" + direction + ".gif'/>");
this.image.css({
position: "absolute",
top: "0px",
left: xPos
});
$('.stage').append(this.image);
}// ends CLASS Arrow
// To enable animating the arrows
Arrow.prototype.step = function() {
// Controls the speed of the arrows
this.image.css("top", "+=4px");
};
// Deletes arrows when they get to bottom of page
Arrow.prototype.destroy = function() {
// removes the image of the DOM
this.image.remove();
// Removes the note/arrow from memory/array
notes.splice(0,1);
};
// Explodes arrow when hit
Arrow.prototype.explode = function() {
this.image.remove();
};
// For random arrows
var randNum = 0;
// Frame increasing
var frame = 0;
// Determines the speed of notes
var arrowSpawnRate = 40;
// Random generator for arrows
function randomGen() {
// Randomizes between 1 and 4
randNum = Math.floor(Math.random() * 4) + 1;
if (randNum === 1) {
notes.push(new Arrow("left"));
}
if (randNum === 2) {
notes.push(new Arrow("right"));
}
if (randNum === 3) {
notes.push(new Arrow("up"));
}
if (randNum === 4) {
notes.push(new Arrow("down"));
}
}// ends randomGen()
// Render function //
function render() {
if (frame++ % arrowSpawnRate === 0) {
randomGen();
}
// Animate arrows showering down //
for (var i = notes.length - 1; i >= 0; i--) {
notes[i].step();
// Check for cleanup
if (notes[i].image.position().top > 615) {
notes[i].destroy();
}
}
}// ends render()
// jQuery to animate arrows //
$(document).ready(function () {
// shim layer with setTimeout fallback
window.requestAnimFrame = (function() {
return window.requestAnimationFrame ||
window.webkitRequestAnimationFrame ||
window.mozRequestAnimationFrame ||
function(callback) {
window.setTimeout(callback, 40 / 75);
};
})();
/* place the rAF *before* the render()
to assure as close to 60fps with the
setTimeout fallback. */
// Infinte loop for game play
(function animloop() {
if (gameStarted) {
requestAnimFrame(animloop);
render();
} else {
window.setTimeout(animloop, 1000); // check the state per second
}
})();// ends (function animloop() )
});// ends $(doc).ready
// Listening for when the key is pressed
$(document).keydown( function(event) {
for (var i = 0; i < notes.length; i++) {
console.log(notes[i].image.position().top);
if (event.keyCode == 37 && notes[i].direction == "left") {
if (notes[i].image.position().top > 490 && notes[i].image.position().top < 730) {
console.log("LEFT! "+notes[i].explode());
Score++;
}
}
if (event.keyCode == 38 && notes[i].direction == "up") {
if (notes[i].image.position().top > 490 && notes[i].image.position().top < 730) {
console.log("UP! "+notes[i].explode());
Score++;
}
}
if (event.keyCode == 40 && notes[i].direction == "down") {
if (notes[i].image.position().top > 490 && notes[i].image.position().top < 730) {
console.log("DOWN! "+notes[i].explode());
Score++;
}
}
if (event.keyCode == 39 && notes[i].direction == "right") {
if (notes[i].image.position().top > 490 && notes[i].image.position().top < 730) {
console.log("RIGHT! "+notes[i].explode());
Score++;
}
}
}// ends loop
});// ends $(doc).keyup
function score() {
document.getElementById("Points").innerHTML = Score;
}
HTML 代码：
<html>
<head>
<link rel="icon" href="./arrows/clubbackground.jpg" type="image/gif" sizes="16x16">
<script src="https://code.jquery.com/jquery-1.11.2.min.js"></script>
<script src="jsRev.js" type="text/javascript"></script>
<link rel="stylesheet" type="text/css" href="style.css">
<title>DDR-Project 1</title>
</head>
<body>
<div id="BackgroundScene">
<div id="DanceScoreboard">
<div id="GameStopped"><button id="StartBtn" class="btnStyle" onclick="gameStarted=true;">Begin Game</button>
<br><br><br><div class="Status">Click Begin Game to start</div>
</div>
<div id="GameRunning"><button id="StopBtn" class="btnStyle" onclick="gameStarted=false;">Stop Game</button>
<div id="Status" class="Status"></div>
</div>
<div id="dancePoints" class="Points">Points Earned: <div class="OutputText" id="CorrectCount">0</div>
</div>
</div>
<div class="stage"></div> <!-- ENDS .STAGE -->
<div id="controls">
<img id="left" src="./arrows/staticLeft.png">
<img id="up" src="./arrows/staticUp.png">
<img id="down" src="./arrows/staticDown.png">
<img id="right" src="./arrows/staticRight.png">
</div> <!-- ENDS #CONTROLS -->
</body>
</html>
【问题讨论】：
-
@usman khan - 每当您的
Score更新时，请致电score()。在你html中，没有id 为Points的元素，而是你有类Points。所以不要使用document.getElementById("Points").innerHTML = Score;使用document.querySelector(".Points").innerHTML = Score; -
@random 你能在我的代码中修改它并发布答案吗？
-
@random 我照你说的做了，但一直显示
points earned: 0
标签： javascript html