默认生成的 canvas 图片在 retina 设备上显示很模糊,处理成 2 倍图能解决这个问题:
var w = $( #code ).width();var h = $( #code ).height();//要将 canvas 的宽高设置成容器宽高的 2 倍var canvas = document.createElement( canvas canvas.width = w * 2;canvas.height = h * 2;canvas.style.width = w + px canvas.style.height = h + px var context = canvas.getContext( 2d //然后将画布缩放,将图像放大两倍画到画布上context.scale(2,2);html2canvas(document.querySelector( #code ), { canvas: canvas, onrendered: function(canvas) {});
下载方法:
.on( click , .download ,function(){ $( #mycanvas ).remove(); var _height=$( .skinReport ).height(); //滚到顶部 $( html, body ).animate({scrollTop:0}); if(confirm( 是否下载肌肤检测报告? )) setTimeout(function(){ var canvas = document.createElement( canvas ), w=$( #skinReport ).width(), h=$( #skinReport ).height(); canvas.width = w * 2; canvas.height = h * 2; canvas.style.width = w + px canvas.style.height = h + px var context = canvas.getContext( 2d //然后将画布缩放,将图像放大两倍画到画布上 context.scale(2,2); html2canvas(document.getElementById( skinReport ), { allowTaint: false, taintTest: true, canvas: canvas, onrendered: function(canvas) { canvas.id = mycanvas canvas.style.display = none document.body.appendChild(canvas); //生成base64图片数据 imgData = canvas.toDataURL(type); //var newImg = document.createElement( img //newImg.src = dataUrl; //document.body.appendChild(newImg); //console.log(imgData); var _fixType = function(type) { type = type.toLowerCase().replace(/jpg/i, jpeg var r = type.match(/png|jpeg|bmp|gif/)[0]; return image/ + r; // 加工image data,替换mime type imgData = imgData.replace(_fixType(type), image/octet-stream * 在本地进行文件保存 * @param {String} data 要保存到本地的图片数据 * @param {String} filename 文件名 var saveFile = function(data, filename){ var save_link = document.createElementNS( http://www.w3.org/1999/xhtml , a save_link.href = data; save_link.download = filename; var event = document.createEvent( MouseEvents event.initMouseEvent( click , true, false, window, 0, 0, 0, 0, 0, false, false, false, false, 0, null); save_link.dispatchEvent(event); // 下载后的问题名 var filename = aname+ 肌肤检测报告 + (new Date()).getTime() + . + type; // download saveFile(imgData,filename); width:1512, height:15000 },2500) else return; })
上面是我整理给大家的,希望今后会对大家有帮助。
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以上就是html2canvas把div保存图片高清图(图文教程)的详细内容,html教程
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