SOURCE

console 命令行工具 X clear

                    
>
console
const a = document.querySelector('#aaa')

a.onchange = e=>{
    alert("导入成功")
}
<style>
    .cccuuu{
    background-color: rgb(10, 76, 255);
    color: #fff;
    padding: 24px 8px;
    border-radius: 6px;
    
}
</style>
<label for="aaa" class="cccuuu">导入课表</label>
<input type="file" hidden id="aaa">