Bootstrap4 面包屑导航+表单+输入框组+自定义表单

Bootstrap4 面包屑导航（Breadcrumb）

<ul class="breadcrumb">
    <li class="breadcrumb-item"><a href="#">item1</a></li>
    <li class="breadcrumb-item"><a href="#">item2</a></li>
    <li class="breadcrumb-item"><a href="#">item3</a></li>
</ul>

也可以不用列表形式

<nav class="breadcrumb">
    <a href="#" class="breadcrumb-item">item1</a>
    <a href="#" class="breadcrumb-item">item2</a>
    <a href="#" class="breadcrumb-item">item3</a>
</nav>

Bootstrap4 表单

堆叠表单

<form action="">
    <div class="form-group">
        <label for="">username</label>
        <input type="text" class="form-control">
    </div>
    <div class="form-group">
        <label for="">password</label>
        <input type="password" class="form-control">
    </div>
</form>

内联表单

所有内联表单中的元素都是左对齐的。
注意：在屏幕宽度小于 576px 时为垂直堆叠，如果屏幕宽度大于等于576px时表单元素才会显示在同一个水平线上

<form class="form-inline">
    <div class="form-group">
        <label for="">username</label>
        <input type="text" class="form-control">
    </div>
    <div class="form-group">
        <label for="">password</label>
        <input type="password" class="form-control">
    </div>
</form>

Bootstrap4 输入框组

<form>
    <div class="input-group mb-3">
        <div class="input-group-prepend">
            <span class="input-group-text">@</span>
        </div>
        <input type="email">
    </div>
    <div class="input-group mb-3">        
        <input type="email">
        <div class="input-group-append">
            <span class="input-group-text">@qq.com</span>
        </div>
    </div>
</form>

文本信息可以使用复选框与单选框替代

<form>
    <div class="input-group mb-3">
        <div class="input-group-prepend">
            <div class="input-group-text">
                <input type="checkbox" name="" id="">
            </div>
        </div>
        <input type="email">
    </div>
    <div class="input-group mb-3">        
        <input type="email">
        <div class="input-group-append">
            <div class="input-group-text">
                <input type="radio" name="" id="">
            </div>
        </div>
    </div>
</form>

输入框添加按钮组

<form>
    <div class="input-group mb-3">
        <div class="input-group-prepend">
            <button type="button" class="btn btn-primary">提交</button>
        </div>
        <input type="email">
    </div>
    <div class="input-group mb-3">        
        <input type="email">
        <div class="input-group-append">
            <button type="submit" class="btn btn-primary">提交</button>
        </div>
    </div>
</form>

输入框中添加下拉菜单

<form>
    <div class="input-group mb-3">
        <div class="input-group-prepend">
            <button type="button" class="btn btn-primary dropdown-toggle" data-toggle="dropdown">提交</button>
            <div class="dropdown-menu">
                <a href="#" class="dropdown-item">item1</a>
                <a href="#" class="dropdown-item">item2</a>
                <a href="#" class="dropdown-item">item3</a>
            </div>    
        </div>    
        <input type="email">
    </div>
</form>

输入框组标签

<form>
    <label for="email">write your email here:</label>
    <div class="input-group mb-3">        
        <input type="email" id="email">
        <div class="input-group-append">
            <span class="input-group-text">@qq.com</span>
        </div>    
    </div>
</form>

Bootstrap4 自定义表单

自定义复选框

<form>
    <div class="custom-control custom-checkbox">
        <input type="checkbox" name="hobby" id="hobby" class="custom-control-input">
        <label for="hobby" class="custom-control-label">hobby</label>
    </div>
</form>

自定义单选框

<form>
    <div class="custom-control custom-radio">
        <input type="radio" name="hobby" id="hobby" class="custom-control-input">
        <label for="hobby" class="custom-control-label">hobby</label>
    </div>
</form>

自定义下拉选择菜单

<form>
    <select name="" id="" class="custom-select-sm">
        <option selected>请选择</option>
        <option value="1">item1</option>
        <option value="2">item2</option>
        <option value="3">item3</option>
    </select>
</form>

自定义滑块控件

<form>
    <label for="range">range</label>
    <input type="range" class="custom-range" />
</form>

<form>
    <div class="custom-file" style="200px;">
        <label for="file" class="custom-file-label">选择文件</label>
        <input type="file" class="custom-file-input" input="file" />
    </div>
</form>

总结一下，自定义表单控件比默认的表单控件颜值更高！