Bootstrap导航栏下拉菜单/折叠的导航栏未打开
[英]Bootstrap navbar dropdown menu/collapsed navbar not opening
问题描述
I am trying to add a navbar to this website, but for some reason it is not functioning how I thought it would. 
我正在尝试向该网站添加导航栏，但是由于某些原因，它无法正常运行。 The main problem I am trying to solve is getting the dropdown menu to actually display the list. 我要解决的主要问题是获取下拉菜单以实际显示列表。 It visually looks like the menu is already expanded, but I don't know if that has anything to do with why it is not working. 从外观上看，菜单似乎已经展开，但是我不知道这是否与为什么它不起作用有关。 Currently, the collapsed version will open from the hamburger menu only because of the CSS I added. 目前，由于我添加的CSS，折叠后的版本只能从汉堡包菜单中打开。 Without the CSS, that navbar will expand, but immediately collapse again. 没有CSS，该导航栏将扩展，但立即会再次崩溃。 Things I have tried: 我尝试过的事情：
- I have tried to switch the order that I include Bootstrap.js/css and jQuery, but that has no effect on it. 我试图切换包含Bootstrap.js / css和jQuery的顺序，但这对它没有影响。
- I have also tried to switch versions because I am not sure what is compatible with what, but that has not been successful. 我也尝试过切换版本，因为我不确定什么与什么兼容，但是那没有成功。
- The one thing that did work was using an old version of bootstrap, but I would like to use 4.0 or higher if that is possible. 起作用的一件事是使用旧版本的引导程序，但如果可能的话，我想使用4.0或更高版本。
I would appreciate it is someone could help me figure out why this is not working. 我会很感激有人可以帮助我弄清楚为什么它不起作用。 Thanks! 谢谢！
.navbar-collapse.collapse.in { display: block!important; }
<!DOCTYPE html> <html> <head> <title>Title</title> <script src="https://code.jquery.com/jquery-3.2.1.min.js"> </script> <script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script> <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css"> <link rel="stylesheet" href="index.css"> </head> <body> <nav class="navbar navbar-expand-lg navbar-light bg-light"> <a class="navbar-brand" href="#">Navbar</a> <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarSupportedContent" aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation"> <span class="navbar-toggler-icon"></span> </button> <div class="collapse navbar-collapse" id="navbarSupportedContent"> <ul class="navbar-nav mr-auto"> <li class="nav-item active"> <a class="nav-link" href="#">Home <span class="sr-only">(current)</span></a> </li> <li class="nav-item"> <a class="nav-link" href="#">Link</a> </li> <li class="nav-item dropdown"> <a class="nav-link dropdown-toggle" href="#" id="navbarDropdown" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false"> Products </a> <div class="dropdown-menu" aria-labelledby="navbarDropdown"> <a class="dropdown-item" href="#">Action</a> <a class="dropdown-item" href="#">Another action</a> <div class="dropdown-divider"></div> <a class="dropdown-item" href="#">Something else here</a> </div> </li> <li class="nav-item"> <a class="nav-link" href="#">About Us</a> </li> </ul> <form class="form-inline my-2 my-lg-0"> <input class="form-control mr-sm-2" type="search" placeholder="Search" aria-label="Search"> <button class="btn btn-outline-success my-2 my-sm-0" type="submit">Search</button> </form> </div> </nav> <div class="jumbotron"> <h1 class="display-3">Hello, world!</h1> <p class="lead">This is a simple hero unit, a simple jumbotron-style component for calling extra attention to featured content or information.</p> <hr class="my-4"> <p>It uses utility classes for typography and spacing to space content out within the larger container.</p> <p class="lead"> <a class="btn btn-primary btn-lg" href="#" role="button">Learn more</a> </p> </div> </body> </html>
1 个解决方案
解决方案1
2 已采纳 2018-10-02 20:06:36
That's because your bootstrap.js is version 3.3.7, and this is not how you implement sub-menu (on bootstrap 3). 这是因为bootstrap.js版本是3.3.7，这不是实现子菜单（在bootstrap 3上）的方式。 Although, If you're using bootstrap 4 already, you should consider updating your bootstrap.js to version 4.0.0 (And you should use the same versions of bootstrap.js and bootstrap.css to avoid unexepected bugs (like you just had). 虽然，如果您已经在使用bootstrap 4，则应考虑将bootstrap.js更新到版本4.0.0（并且应该使用相同版本的bootstrap.js和bootstrap.css以避免意外的错误（就像您刚遇到的一样） 。
.navbar-collapse.collapse.in { display: block!important; }
<!DOCTYPE html> <html> <head> <title>Title</title> <script src="https://code.jquery.com/jquery-3.2.1.min.js"> </script> <script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/js/bootstrap.min.js"></script> <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css"> <link rel="stylesheet" href="index.css"> </head> <body> <nav class="navbar navbar-expand-lg navbar-light bg-light"> <a class="navbar-brand" href="#">Navbar</a> <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarSupportedContent" aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation"> <span class="navbar-toggler-icon"></span> </button> <div class="collapse navbar-collapse" id="navbarSupportedContent"> <ul class="navbar-nav mr-auto"> <li class="nav-item active"> <a class="nav-link" href="#">Home <span class="sr-only">(current)</span></a> </li> <li class="nav-item"> <a class="nav-link" href="#">Link</a> </li> <li class="nav-item dropdown"> <a class="nav-link dropdown-toggle" href="#" id="navbarDropdown" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false"> Products </a> <div class="dropdown-menu" aria-labelledby="navbarDropdown"> <a class="dropdown-item" href="#">Action</a> <a class="dropdown-item" href="#">Another action</a> <div class="dropdown-divider"></div> <a class="dropdown-item" href="#">Something else here</a> </div> </li> <li class="nav-item"> <a class="nav-link" href="#">About Us</a> </li> </ul> <form class="form-inline my-2 my-lg-0"> <input class="form-control mr-sm-2" type="search" placeholder="Search" aria-label="Search"> <button class="btn btn-outline-success my-2 my-sm-0" type="submit">Search</button> </form> </div> </nav> <div class="jumbotron"> <h1 class="display-3">Hello, world!</h1> <p class="lead">This is a simple hero unit, a simple jumbotron-style component for calling extra attention to featured content or information.</p> <hr class="my-4"> <p>It uses utility classes for typography and spacing to space content out within the larger container.</p> <p class="lead"> <a class="btn btn-primary btn-lg" href="#" role="button">Learn more</a> </p> </div> </body> </html>
声明:本站的技术帖子网页，遵循CC BY-SA 4.0协议，如果您需要转载，请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.