html2canvas使用

引入

import html2canvas from 'html2canvas'

使用

        //获取详情
        getinfo(hid,sign){
            this.loading=true
            this.$apiRequest('details', {
                "hid":Number(hid),
                "sign":sign
            }).then(res => {
                this.info = res.data
               // alert(res.data.avatar)
                this.$nextTick(()=>{
                if(res.data.poster_type==="0"){
                    this.$nextTick(()=>{
                        
                        setTimeout(()=>{
                            let poster = document.getElementById("haibaoone");
                            this.createImg(poster)
                        },500)  
                    })
                }else if(res.data.poster_type==="1"){
                    setTimeout(()=>{
                        let poster = document.getElementById("haibaotwo");
                        this.createImg(poster)
                    },500) 
                }
                
                    
                })
               
            })
        },
        //生成图片
        createImg(dom) {
            //const poster = document.getElementById("haibao");
            let that = this
            html2canvas(dom, {
                dpi: 80,
                useCORS: true,
                scale: 4,
                async: true,
                //  dom.offsetWidth,
                // height: dom.offsetHeight
                x: that.getActuralPosition(dom).left + parseInt(that.getScrollWidth()/2),
                y: that.getActuralPosition(dom).top,
            }).then((canvas) => {
                this.imgSrc = canvas.toDataURL("image/jpeg");
                this.showdiv = false
                this.loading=false
                //console.log(this.imgSrc)
            }).catch(() => {
              
            })
        },
        //获取网页元素的绝对位置
        getActuralPosition(element){
            let acturalLeft = element.offsetLeft;
            let acturalTop = element.offsetTop;
            let curElement =  element.offsetParent;
            while(curElement){
                acturalLeft += curElement.offsetLeft;
                acturalTop += curElement.offsetTop;
                curElement = curElement.offsetParent;
            }
            return {
                left: acturalLeft,
                top: acturalTop,
            }
        },
        // 获取滚动条的宽度
        getScrollWidth() {
            // 创建一个div元素
            let noScroll, scroll, oDiv = document.createElement('DIV');
            oDiv.style.cssText = 'position:absolute; top:-1000px; 100px; height:100px; overflow:hidden;';
            // 没有滚动条的clientWidth  clientWidth为content+paddingLeft+paddingRight 不包括滚动//条，可以利用这个获取差值来求滚动条的宽度
            noScroll = document.body.appendChild(oDiv).clientWidth;
            oDiv.style.overflowY = 'scroll';
            scroll = oDiv.clientWidth;
            document.body.removeChild(oDiv);
            return noScroll-scroll;
        },