Question

我有一个学校项目，我想编制一个游戏网站，但我从另一个网站复制的游戏始终位于顶部，你可以帮我把它搞定吗？我希望游戏在热门栏下的网站中心:) HTML代码：

 <!DOCTYPE html>
    <html>
    <head>
        <title>Games</title>
        <meta name="viewport" content="width=device-width, initial-scale=1.0"/>
        <link rel="stylesheet" href="css/nav.css">
        <style>
    canvas {
        border:1px solid #d3d3d3;
        background-color: #f1f1f1;
    }
    </style>
    </head>
    <body onload="startGame()">
         <div class="nav">
            <ul>
                <li><a href="">Aventure Games</a></li>
                <li><a href="">1vs1 Games</a></li>
                <li id="logo"><img src="src/logogif.gif" style="width:300px;"></li>
                <li><a href="">Other Categories</a></li>
                <li><a href="">About us</a></li>
            </ul>
        </div>
        <article>
            <h1>Games</h1>
            <p>content bla bla</p>
        </article>


        <p class="flappybird">
        <script>

    var myGamePiece;
    var myObstacles = [];
    var myScore;

    function startGame() {
        myGamePiece = new component(30, 30, "red", 10, 120);
        myGamePiece.gravity = 0.05;
        myScore = new component("30px", "Consolas", "black", 280, 40, "text");
        myGameArea.start();
    }

    var myGameArea = {
        canvas : document.createElement("canvas"),
        start : function() {
            this.canvas.width = 480;
            this.canvas.height = 270;
            this.context = this.canvas.getContext("2d");
            document.body.insertBefore(this.canvas, document.body.childNodes[0]);
            this.frameNo = 0;
            this.interval = setInterval(updateGameArea, 20);
            },
        clear : function() {
            this.context.clearRect(0, 0, this.canvas.width, this.canvas.height);
        }
    }

    function component(width, height, color, x, y, type) {
        this.type = type;
        this.score = 0;
        this.width = width;
        this.height = height;
        this.speedX = 0;
        this.speedY = 0;    
        this.x = x;
        this.y = y;
        this.gravity = 0;
        this.gravitySpeed = 0;
        this.update = function() {
            ctx = myGameArea.context;
            if (this.type == "text") {
                ctx.font = this.width + " " + this.height;
                ctx.fillStyle = color;
                ctx.fillText(this.text, this.x, this.y);
            } else {
                ctx.fillStyle = color;
                ctx.fillRect(this.x, this.y, this.width, this.height);
            }
        }
        this.newPos = function() {
            this.gravitySpeed += this.gravity;
            this.x += this.speedX;
            this.y += this.speedY + this.gravitySpeed;
            this.hitBottom();
        }
        this.hitBottom = function() {
            var rockbottom = myGameArea.canvas.height - this.height;
            if (this.y > rockbottom) {
                this.y = rockbottom;
                this.gravitySpeed = 0;
            }
        }
        this.crashWith = function(otherobj) {
            var myleft = this.x;
            var myright = this.x + (this.width);
            var mytop = this.y;
            var mybottom = this.y + (this.height);
            var otherleft = otherobj.x;
            var otherright = otherobj.x + (otherobj.width);
            var othertop = otherobj.y;
            var otherbottom = otherobj.y + (otherobj.height);
            var crash = true;
            if ((mybottom < othertop) || (mytop > otherbottom) || (myright < otherleft) || (myleft > otherright)) {
                crash = false;
            }
            return crash;
        }
    }

    function updateGameArea() {
        var x, height, gap, minHeight, maxHeight, minGap, maxGap;
        for (i = 0; i < myObstacles.length; i += 1) {
            if (myGamePiece.crashWith(myObstacles[i])) {
                return;
            } 
        }
        myGameArea.clear();
        myGameArea.frameNo += 1;
        if (myGameArea.frameNo == 1 || everyinterval(150)) {
            x = myGameArea.canvas.width;
            minHeight = 20;
            maxHeight = 200;
            height = Math.floor(Math.random()*(maxHeight-minHeight+1)+minHeight);
            minGap = 50;
            maxGap = 200;
            gap = Math.floor(Math.random()*(maxGap-minGap+1)+minGap);
            myObstacles.push(new component(10, height, "green", x, 0));
            myObstacles.push(new component(10, x - height - gap, "green", x, height + gap));
        }
        for (i = 0; i < myObstacles.length; i += 1) {
            myObstacles[i].x += -1;
            myObstacles[i].update();
        }
        myScore.text="SCORE: " + myGameArea.frameNo;
        myScore.update();
        myGamePiece.newPos();
        myGamePiece.update();
    }

    function everyinterval(n) {
        if ((myGameArea.frameNo / n) % 1 == 0) {return true;}
        return false;
    }

    function accelerate(n) {
        myGamePiece.gravity = n;
    }
    </script>
    <br>
    <button onmousedown="accelerate(-0.2)" onmouseup="accelerate(0.05)">ACCELERATE</button>
    <p>Use the ACCELERATE button to stay in the air</p>
    <p>How long can you stay alive?</p>
    </body>
    </html>

CSS代码：

*{

        margin: 0px;
        background-color:darkred;
    }
    .nav{
        height: 100px;
    }

    ul {
        list-style-type: none;
        margin: 0;
        padding: 0;
        text-align: center;
        /*padding-left: 30%;
        padding-right: 30%;*/
        /*overflow: hidden;*/
        background-color: gray;
        height:70px;
    }

    li {
        /*float: left;*/
        display: inline-block;
        vertical-align: top;
        margin: 0 -2px;

    }

    li a {
        display: block;
        font-family: Verdana, Helvetica, sans-serif;
        color: white;
        text-align: center;
        padding: 14px 16px;
        text-decoration: none;
        background-color: darkred;
    }
    #logo {
        /*display: block;*/
        font-family: Verdana, Helvetica, sans-serif;
        background-color: black;
        text-align: center;
        padding: 10px;
        text-decoration: none;
    }   
    #logo img{
        display: block;
    }

    li a:hover {
        background-color: black;
        color: white;
    }

    }
    p{font-family:Tahoma;}

    article {
        padding-left: 12px;
    }

Answer 1

您需要定义要插入新元素的正确位置，例如画布。在下面的代码片段中，您可以将画布放在文档正文的第一个子节点之前。

document.body.insertBefore(this.canvas, document.body.childNodes[0]);

你需要指定一个元素来放置它，在它下面寻找具有类名flappybird的第一个元素。

document.body.insertBefore(this.canvas, document.getElementsByClassName("flappybird")[0]);

我希望我的游戏位于底部而不是顶部？

1 个答案: