在网页加载完毕时自动触发某个按钮的点击事件
需求： 在使用bootstrap 模态框时 需要模态框在网页加载完毕后自动显示模态框而不是通过按钮激活模态框
解决思路：在window.onload() 方法中激活 模态框按钮的click方法即可
实现：
<!-- Button trigger modal --><button type="button" id="activate" class="btn btn-primary" data-toggle="modal" data-target="#staticBackdrop" hidden>点击展开</button><!-- Modal --><div class="modal fade" id="staticBackdrop" data-backdrop="static" data-keyboard="false" tabindex="-1" aria-labelledby="staticBackdropLabel" aria-hidden="true"><div class="modal-dialog"><div class="modal-content"><div class="modal-header"><h5 class="modal-title" id="staticBackdropLabel">模态框</h5><button type="button" class="close" data-dismiss="modal" aria-label="Close"><span aria-hidden="true">×</span></button></div><div class="modal-body">我是模态框模态框</div><div class="modal-footer"><button type="button" class="btn btn-secondary" data-dismiss="modal">取消</button><button type="button" class="btn btn-primary">同意</button></div></div></div></div>
window.onload = function (){document.querySelector("#activate").click()}
十分简单
