html标签转换成img图片

app 里的元素需要转换成图片

<script src="../assets/js/html2canvas.min.js"></script>

$(function () {
                    html2canvas(document.querySelector("#app"), {useCORS: true}).then(canvas => {
                        layer.close(vm.layerIndex)
                        var img = new Image();
                        img.setAttribute('crossOrigin', 'anonymous');
                        var url = canvas.toDataURL();
                        img.src = url;
                        $('#newApp').append(img).show();
                        $('#newApp img').css({width: '100%',position:"absolute",top:0})
                    });
                })