html2canvas配置

    html2canvas(domObj, {
           useCORS: true,//Whether to attempt to load cross-origin images as CORS served, before reverting back to proxy
           allowTaint: false,//Whether to allow cross-origin images to taint the canvas
           height: domObj.offsetHeight,//Define the heigt of the canvas in pixels. If null, renders with full height of the window
           width: domObj.offsetWidth,
           windowWidth: document.body.scrollWidth,
           windowHeight: document.body.scrollHeight,
           logging: false,//Whether to log events in the console
           x: 0,
           y: scrollTop, // 用网页滚动的高度定位y轴顶点
           dpi: window.devicePixelRatio,
           scale: 1,
         backgroundColor: null,//Canvas background color, if none is specified in DOM. Set undefined for transparent
           letterRendering: true,//Whether to render each letter seperately. Necessary if letter-spacing is used
           onclone (doc) {
                  console.log(doc);
            }
            }).then(canvas => {
                    // 微信里可长按保存或转发
                    const imgData = canvas.toDataURL('image/png');
                    console.log(imgData);
            })
    }