js 下载图片

  downloadIamge(imgsrc, name) {//下载图片地址和图片名

  let image = new Image();

  // 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

    document.removeChild(a)

  };

  image.src = imgsrc;

},