1.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');
/**
* 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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