html通过canvas转成base64的方法

<!--生成后存放的IMG--><img src="" id="saveImages"    <img src="">    <div class="name pa"></div>    <div class="msg pa"></div></div><style>#saveContent{width: 7.5rem; height: 12.27rem; position: relative;}#saveContent img{ width: 100%;}#saveContent .name{color: #7c5234;font-size: .3rem;top: 6.55rem;line-height: .6rem;text-align: center;left: 0;right: 0;}#saveContent .msg{color: #7c5234;font-size: .24rem;top: 7.35rem;text-align: center;left: 0;right: 0;}#saveContent .msg span{ color: #cf5350; font-size: .36rem;}</style>

<!--使用最新版本的html2canvas--><!--官网https://html2canvas.hertzen.com/--><script src="//html2canvas.hertzen.com/dist/html2canvas.min.js"></script><script src="//static.leiting.com/lib/jquery-1.9.0.min.js"></script><script>//生成$(function(){    var isCreate=false;    $('a.create').on('click',function(){        isCreate=true;                $('#saveContent img').attr('src','//activity.leiting.com/wd/201904/data/images/pop/1.jpg');        $('#saveContent .name').html('aaaaaa');        $('#saveContent .msg').html('bbbbbbbbbb');        html2canvas(document.getElementById('saveContent'), {            onrendered: function(ca) {                $('#saveImages').attr('src',ca.toDataURL('image/jpeg'));            }        });    })})</script>