export const exportImg = function (imgsrc,name) { /* url图片地址，name图片名称 */
    // 不跨域
    // let alink = document.createElement('a');
    // alink.href = url;
    // alink.download = name || '图片下载'; //图片名
    // window.open(alink);
    let image = new Image();
    // 跨域，解决跨域 Canvas 污染问题
    image.setAttribute('crossOrigin', 'anonymous');
    image.onload = function() {
        let canvas = document.createElement('canvas');
        canvas.width = image.width;
        canvas.height = image.height;
        let context = canvas.getContext('2d');
        context.drawImage(image, 0, 0, image.width, image.height);
        let url = canvas.toDataURL('image/png'); //得到图片的base64编码数据

        let a = document.createElement('a'); // 生成一个a元素
        let event = new MouseEvent('click'); // 创建一个单击事件
        a.download = name || 'photo'; // 设置图片名称
        a.href = url; // 将生成的URL设置为a.href属性
        a.dispatchEvent(event); // 触发a的单击事件
    };
    image.src = imgsrc;
};
this.exportImg(url,'图片')

// url格式如http://192.168.0.0:8080/services/school/api/si-file-infos/get-img?imgUrl=C:/Users/Administrator.USER-20170313WG/AppData/Local/Temp/undertow-docbase.4291210821146122927.8085/upload/image/1574317025041001.png