前端下載base64格式圖片時，報錯：Not allowed to navigate top frame to data URL，程式碼如下：
<a href="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABMAAAATCAYAAAByUDbMAAAAIUlEQVQ4jWMUXfH6PwOVABO1DBo1bNSwUcNGDRs1DAcAAJNsAs1wYr6uAAAAAElFTkSuQmCC">
<el-button type="primary" size="mini">下載</el-button>
</a>點選按鈕竟然報錯了，給a標籤加上 download="專用二維碼"，如下：
<a :href="receive_qr_url" download="專用二維碼">
<el-button type="primary" size="mini">下載</el-button>
</a>問題解決。