html2canvas如何截高清全图

简单直接上js代码

var w = $(".document").width();
var h = document.body.scrollHeight;
var canvas = document.createElement("canvas");
canvas.width = w * 2;
canvas.height = h * 2;
canvas.style.width = w + "px";
canvas.style.height = h + "px";
var context = canvas.getContext("2d");
context.scale(2, 2);
html2canvas($(".document"), {
canvas : canvas,
onrendered : function(canvas) {
var url = canvas.toDataURL("image/jpeg");

//下载图片代码             var triggerDownload = $("<a>").attr("href", url).attr("download", getNowFormatDate()+"异常信息.png").appendTo("body");               triggerDownload[0].click();               triggerDownload.remove();

},
"background" : '#FFFFFF'
});