JavaScript属性值不更新引导样式

JavaScript属性值不更新引导样式,javascript,twitter-bootstrap,Javascript,Twitter Bootstrap,我从嵌入式脚本创建了一个按钮,但是添加的引导样式“btn btn success”没有显示绿色按钮。 <body> <div class="container"> <main> </main> <aside> <hr> <button onclick="createElementBtn();">Create a button</button><b

我从嵌入式脚本创建了一个按钮,但是添加的引导样式“btn btn success”没有显示绿色按钮。

<body>
<div class="container">
    <main>
    </main>
    <aside>
        <hr>
    <button onclick="createElementBtn();">Create a button</button><br />
    </aside>
</div>  <!-- /container -->
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.3/jquery.min.js"></script>
<script src="http://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/js/bootstrap.min.js"></script>
<script>
function createElementBtn(){
        var bodyEl = document.getElementsByTagName("body")[0];
        var mainEl = bodyEl.getElementsByTagName("main")[0];
        var btn = document.createElement("button");
        btn.type='button';
        btn.class='btn btn-success';
        btn.innerHTML='Basic Button';
        mainEl.appendChild(btn);
}
</script>
</body>
</html>


创建一个按钮
函数createElementBtn(){ var bodyEl=document.getElementsByTagName(“主体”)[0]; var mainEl=bodyEl.getElementsByTagName(“main”)[0]; var btn=document.createElement(“按钮”); btn.type='button'; btn.class='btn btn success'; btn.innerHTML='Basic Button'; 主语、副词(btn); }
您应该修改元素的
className
属性,而不是定义
class
属性

<body>
<div class="container">
    <main>
    </main>
    <aside>
        <hr>
    <button onclick="createElementBtn();">Create a button</button><br />
    </aside>
</div>  <!-- /container -->
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.3/jquery.min.js"></script>
<script src="http://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/js/bootstrap.min.js"></script>
<script>
function createElementBtn(){
        var bodyEl = document.getElementsByTagName("body")[0];
        var mainEl = bodyEl.getElementsByTagName("main")[0];
        var btn = document.createElement("button");
        btn.type='button';
        btn.class='btn btn-success';
        btn.innerHTML='Basic Button';
        mainEl.appendChild(btn);
}
</script>
</body>
</html>
btn.className = 'btn btn-success';
btn.className = 'btn btn-success';

您应该修改元素的
className
属性,而不是定义
class
属性

<body>
<div class="container">
    <main>
    </main>
    <aside>
        <hr>
    <button onclick="createElementBtn();">Create a button</button><br />
    </aside>
</div>  <!-- /container -->
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.3/jquery.min.js"></script>
<script src="http://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/js/bootstrap.min.js"></script>
<script>
function createElementBtn(){
        var bodyEl = document.getElementsByTagName("body")[0];
        var mainEl = bodyEl.getElementsByTagName("main")[0];
        var btn = document.createElement("button");
        btn.type='button';
        btn.class='btn btn-success';
        btn.innerHTML='Basic Button';
        mainEl.appendChild(btn);
}
</script>
</body>
</html>
btn.className = 'btn btn-success';
btn.className = 'btn btn-success';
试试这个:

<body>
<div class="container">
    <main>
    </main>
    <aside>
        <hr>
    <button onclick="createElementBtn();">Create a button</button><br />
    </aside>
</div>  <!-- /container -->
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.3/jquery.min.js"></script>
<script src="http://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/js/bootstrap.min.js"></script>
<script>
function createElementBtn(){
        var bodyEl = document.getElementsByTagName("body")[0];
        var mainEl = bodyEl.getElementsByTagName("main")[0];
        var btn = document.createElement("button");
        btn.type='button';
        btn.class='btn btn-success';
        btn.innerHTML='Basic Button';
        mainEl.appendChild(btn);
}
</script>
</body>
</html>
btn.classList.add('btn');
btn.classList.add('btn-success');
或按类名:

<body>
<div class="container">
    <main>
    </main>
    <aside>
        <hr>
    <button onclick="createElementBtn();">Create a button</button><br />
    </aside>
</div>  <!-- /container -->
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.3/jquery.min.js"></script>
<script src="http://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/js/bootstrap.min.js"></script>
<script>
function createElementBtn(){
        var bodyEl = document.getElementsByTagName("body")[0];
        var mainEl = bodyEl.getElementsByTagName("main")[0];
        var btn = document.createElement("button");
        btn.type='button';
        btn.class='btn btn-success';
        btn.innerHTML='Basic Button';
        mainEl.appendChild(btn);
}
</script>
</body>
</html>
试试这个:

<body>
<div class="container">
    <main>
    </main>
    <aside>
        <hr>
    <button onclick="createElementBtn();">Create a button</button><br />
    </aside>
</div>  <!-- /container -->
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.3/jquery.min.js"></script>
<script src="http://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/js/bootstrap.min.js"></script>
<script>
function createElementBtn(){
        var bodyEl = document.getElementsByTagName("body")[0];
        var mainEl = bodyEl.getElementsByTagName("main")[0];
        var btn = document.createElement("button");
        btn.type='button';
        btn.class='btn btn-success';
        btn.innerHTML='Basic Button';
        mainEl.appendChild(btn);
}
</script>
</body>
</html>
btn.classList.add('btn');
btn.classList.add('btn-success');
或按类名:

<body>
<div class="container">
    <main>
    </main>
    <aside>
        <hr>
    <button onclick="createElementBtn();">Create a button</button><br />
    </aside>
</div>  <!-- /container -->
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.3/jquery.min.js"></script>
<script src="http://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/js/bootstrap.min.js"></script>
<script>
function createElementBtn(){
        var bodyEl = document.getElementsByTagName("body")[0];
        var mainEl = bodyEl.getElementsByTagName("main")[0];
        var btn = document.createElement("button");
        btn.type='button';
        btn.class='btn btn-success';
        btn.innerHTML='Basic Button';
        mainEl.appendChild(btn);
}
</script>
</body>
</html>