canvas 导入序列帧+图片预加载

修改图片路径
<!doctype html>
<html lang="zh">
<head>
    <meta charset="UTF-8">
    <title>canvas导入序列帧</title>
    <script>
        // 立即生成兼容VIEWPORT
        (function () {
            var phoneWidth = parseInt(window.screen.width);
            var phoneScale = phoneWidth / 640;
            var ua = navigator.userAgent;
            if (/Android (d+.d+)/.test(ua)) {
                // window.location.href = 'Android.html';
                var version = parseFloat(RegExp.$1);
                if (version > 2.3) {
                    // andriod 2.3以上
                    document.write('<meta name="viewport" content="width=640, minimum-scale = ' + phoneScale + ', maximum-scale = ' + phoneScale + ', target-densitydpi=device-dpi">');
                } else {
                    // andriod 2.3
                    document.write('<meta name="viewport" content="width=640, target-densitydpi=device-dpi">');
                }
                // IOS及其他系统
            } else {
                document.write('<meta name="viewport" content="width=640, user-scalable=no">');
            }
        })();
    </script>
    <!--<link rel="stylesheet" href="css/index.css">-->
</head>
<body>
<canvas id="animation_canvas" width="640" height="1030" style="background-color: #fff;"></canvas>
</body>
<script src="https://cdn.bootcss.com/jquery/3.3.1/jquery.min.js"></script>
<script src="http://h5.appro.cc/Resources/js/global.min.js"></script>
<script src="http://res.wx.qq.com/open/js/jweixin-1.0.0.js"></script>
<script src="http://h5.appro.cc/Resources/js/wxOAuth.min.2.0.js"></script>
<script>
    //初始化参数
    var canvas = null;
    var ctx = null;
    //预加载序列图片
    function loadImages(sources,callback){
        var loadedImages = 0;
        var numImages = 0;
        var images=[];
        var clearWidth=canvas.width;
        var clearHeight=canvas.height;
        // get num of sources
        numImages=sources.length;
        for (var i=0,len=sources.length;i<len;i++) {
            images[i] = new Image();
            //当一张图片加载完成时执行
            images[i].onload = function(){
                //当所有图片加载完成时,执行回调函数callback
                if (++loadedImages >= numImages) {
                    callback(images);
                }
            };
            //把sources中的图片信息导入images数组
            images[i].src = sources[i];
//            console.log(images);
        }
    }
    //播放图片动画
    function playImages(images){
        var imageNum=images.length;
        var imageNow=0;
        setInterval(function(){
//      ctx.fillStyle="rgba(0,0,0,0)";
            ctx.clearRect(0,0,640,1030);
            ctx.fillRect(0, 0, 640, 1030);
            ctx.drawImage(images[imageNow], 0, 0, 640, 1030);
            imageNow++;
            if(imageNow>=imageNum){
                imageNow=89;
            }
        },100)
    }
    //初始化
    window.onload = function(){
        var sources = [];
        //构建图片序列数据
        for(var i=0;i<=146;i++){
            sources[i] = 'images/0/01_' + i + '.png';//根据项目修改
        }
        canvas = document.getElementById("animation_canvas");
        canvas.width = 640;
        canvas.height = 1030;

        ctx = canvas.getContext("2d");
        //ctx.globalAlpha=0.5
        //执行图片预加载,加载完成后执行main
        loadImages(sources,function(images){
            playImages(images)
        });
    };

</script>
<script type="text/javascript" src="http://tajs.qq.com/stats?sId=52797855" charset="UTF-8"></script>
</html>
原文地址:https://www.cnblogs.com/llllpzyy/p/8884841.html