这篇文章将为大家详细讲解有关html2canvas如何实现将div保存图片高清图,小编觉得挺实用的,因此分享给大家做个参考,希望大家阅读完这篇文章后可以有所收获。
本文介绍了html2canvas把div保存图片高清图的方法示例,分享给大家,具体如下:
选择html2canvas版本(这个版本可以放大倍数保证图片清晰)
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'); 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; } })
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