vue 圖片轉base 64

// 將圖片轉換為Base64
imageUrlToBase64(img) {
  // 一定要設置為let，不然圖片不顯示
  let image = new Image();
  // 解決跨域問題
  image.setAttribute('crossOrigin', 'anonymous');
  let imageUrl = img;
  image.src = imageUrl;
  // image.onload為異步加載
  image.onload = () => {
    this.getImage(image);
  };
},
getImage(image) {
  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 quality = 0.8;
  // 這里的dataurl就是base64類型
  let dataURL = canvas.toDataURL('image/jpeg', quality);
  
},