前端下載base64格式圖片時，報錯：Not allowed to navigate top frame to data URL，代碼如下：

<a href="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABMAAAATCAYAAAByUDbMAAAAIUlEQVQ4jWMUXfH6PwOVABO1DBo1bNSwUcNGDRs1DAcAAJNsAs1wYr6uAAAAAElFTkSuQmCC">
    <el-button type="primary" size="mini">下載</el-button>
</a>

點擊按鈕竟然報錯了，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。