html2canvas把div保存图片高清图的方法示例
author:一佰互联 2019-04-20   click:157

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:

http://www.bootcdn.cn/(可以搜索html2canvans)

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;                }            })

以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持网页设计。